Respiratory CO2 response depends on plasma bicarbonate concentration in mechanically ventilated patients

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Maraví-Poma, E. Patchen Dellinger, C.E. Forsmark, P. Layer, P. Lévy, T. Shimosegawa, A.K. Siriwardena, G. Uomo, D.C. Whitcomb, J.A. Windsor, M.S. Petrov" "autores" => array:12 [ 0 => array:2 [ "nombre" => "E." "apellidos" => "Maraví-Poma" ] 1 => array:2 [ "nombre" => "E." "apellidos" => "Patchen Dellinger" ] 2 => array:2 [ "nombre" => "C.E." "apellidos" => "Forsmark" ] 3 => array:2 [ "nombre" => "P." "apellidos" => "Layer" ] 4 => array:2 [ "nombre" => "P." "apellidos" => "Lévy" ] 5 => array:2 [ "nombre" => "T." "apellidos" => "Shimosegawa" ] 6 => array:2 [ "nombre" => "A.K." "apellidos" => "Siriwardena" ] 7 => array:2 [ "nombre" => "G." "apellidos" => "Uomo" ] 8 => array:2 [ "nombre" => "D.C." "apellidos" => "Whitcomb" ] 9 => array:2 [ "nombre" => "J.A." "apellidos" => "Windsor" ] 10 => array:2 [ "nombre" => "M.S." 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"apellidos" => "Fernández Fernández" ] ] ] ] ] "idiomaDefecto" => "es" "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/S021056911400014X?idApp=WMIE" "url" => "/02105691/0000003800000004/v1_201404270108/S021056911400014X/v1_201404270108/es/main.assets" ] "en" => array:19 [ "idiomaDefecto" => true "cabecera" => "ORIGINAL" "titulo" => "Respiratory CO2 response depends on plasma bicarbonate concentration in mechanically ventilated patients" "tieneTextoCompleto" => true "paginas" => array:1 [ 0 => array:2 [ "paginaInicial" => "203" "paginaFinal" => "210" ] ] "autores" => array:1 [ 0 => array:4 [ "autoresLista" => "G. Rialp, J.M. Raurich, J.A. Llompart-Pou, I. Ayestarán, J. Ibáñez" "autores" => array:5 [ 0 => array:3 [ "nombre" => "G." "apellidos" => "Rialp" "referencia" => array:1 [ 0 => array:2 [ "etiqueta" => "a" "identificador" => "aff0005" ] ] ] 1 => array:4 [ "nombre" => "J.M." 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"apellidos" => "Ibáñez" "referencia" => array:1 [ 0 => array:2 [ "etiqueta" => "b" "identificador" => "aff0010" ] ] ] ] "afiliaciones" => array:2 [ 0 => array:3 [ "entidad" => "Servei de Medicina Intensiva, Hospital Son Llàtzer, Palma de Mallorca, Illes Balears, Spain" "etiqueta" => "a" "identificador" => "aff0005" ] 1 => array:3 [ "entidad" => "Servei de Medicina Intensiva, Hospital Universitari Son Espases, Palma de Mallorca, Illes Balears, Spain" "etiqueta" => "b" "identificador" => "aff0010" ] ] "correspondencia" => array:1 [ 0 => array:3 [ "identificador" => "cor0005" "etiqueta" => "⁎" "correspondencia" => "Corresponding author." ] ] ] ] "titulosAlternativos" => array:1 [ "es" => array:1 [ "titulo" => "La respuesta respiratoria al CO2 depende de la concentración plasmática de bicarbonato en pacientes sometidos a ventilación mecánica" ] ] "resumenGrafico" => array:2 [ "original" => 0 "multimedia" => array:7 [ "identificador" => "fig0005" "etiqueta" => "Figure 1" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr1.jpeg" "Alto" => 1060 "Ancho" => 1379 "Tamanyo" => 61934 ] ] "descripcion" => array:1 [ "en" => "Relationship between plasma bicarbonate concentration grouped in tertiles and baseline minute volume expressed by body weight in mL/min/kg, in non-COPD (white circles) and COPD patients (black circles). Dashed lines show the linear relationship among groups (p<0.001 for each variable). Values are expressed as mean and standard error." ] ] ] "textoCompleto" => "IntroductionElevated plasma bicarbonate concentration is a relatively common entity in critically ill patients that can influence the process of weaning of mechanical ventilation.<a class="elsevierStyleCrossRef" href="#bib0005">1</a> Several factors may contribute to elevated plasma bicarbonate concentration in critically ill patients, such as chronic hypercapnia, permissive hypercapnia in patients with acute respiratory distress syndrome, the use of diuretics and steroids, electrolyte disturbances (hypochloremia, hypokalemia), and hypoalbuminemia, among other factors.<a class="elsevierStyleCrossRef" href="#bib0010">2</a>Elevated plasma bicarbonate concentration may lead to compensatory hypoventilation and subsequent carbon dioxide (CO2) retention to maintain acid-base homeostasis. Also, elevated plasma bicarbonate concentration can blunt the change in hydrogen ion concentration (pH) for a given change in the partial pressure of carbon dioxide (PaCO2), in accordance with the Henderson-Hasselbalch relationship, thereby blunting CO2 response. In spite of this, the effect of plasma bicarbonate concentration on CO2 response is controversial. While some studies including a few number of healthy subjects or stable patients with chronic hypercapnia found that the ventilatory response to CO2 depends on the levels of plasma bicarbonate concentrations,<a class="elsevierStyleCrossRefs" href="#bib0015">3–6</a> other studies found that the CO2 response was not affected by bicarbonate levels.<a class="elsevierStyleCrossRefs" href="#bib0035">7–11</a>To our knowledge, the effect of plasma bicarbonate concentration on the CO2 response during mechanical ventilation has been studied only in patients with obesity-hypoventilation syndrome.<a class="elsevierStyleCrossRef" href="#bib0060">12</a> If such a relationship between the plasma bicarbonate concentration and CO2 response is confirmed in a general population of critically ill patients, normalizing elevated bicarbonate levels could be a useful tool to reduce the time of weaning of mechanical ventilation by increasing the CO2 response. Whether the same occurs in chronic elevations of plasma bicarbonate levels, as in patients with chronic obstructive pulmonary disease (COPD), and in acutely induced elevated plasma bicarbonate, has not been addressed yet.The objectives of this study were to analyze the relationship between the plasma bicarbonate concentration and the variation in pH for a given change in PaCO2 and to evaluate the effect of the level of plasma bicarbonate concentration on CO2 response in patients with and without COPD in the weaning of mechanical ventilation.MethodsPatientsFor the purpose of this analysis we selected cases from a database of patients with mechanical ventilation and CO2 response tests performed. The patients were selected if the CO2 response test was performed on the first day of meeting criteria for a spontaneous breathing trial. The patients were grouped in COPD and non-COPD. COPD was diagnosed according pulmonary function tests by the forced expiratory volume in one second (FEV1) to forced vital capacity (FVC) ratio and the FEV1 expressed as percentage of predicted. We excluded those patients admitted in the intensive care unit (ICU) with acute respiratory failure due to acute injury of the central nervous system, neuromuscular disease or patients with chronic hypercapnia due to other reason than COPD.Patients were retrospectively and non-consecutively studied in two medical-surgical ICUs, at the beginning of the weaning of mechanical ventilation. Hospital research committee approved the study. Informed consent was obtained in all cases from patients or closest relatives. Most of the patients of this study have been included in previous studies of our group.<a class="elsevierStyleCrossRefs" href="#bib0065">13–15</a>ProtocolPatients were studied when the physician in charge considered that they had clinical stability and fulfilled criteria for a spontaneous breathing trial. These criteria included that the patient was hemodynamically stable, without sedation awake and able to obey oral commands, had core temperature below 38.3°C and a ratio of the partial pressure of arterial oxygen (PaO2) to the fraction of inspired oxygen (FiO2) above 150mm Hg with a positive end-expiratory pressure (PEEP) of ≤8cm H2O.When the patients were clinically stable and ready for a spontaneous breathing trial, respiratory neuromuscular function was evaluated by measurement of maximal inspiratory pressure (PImax), maximal expiratory pressure (PEmax), and CO2 response test. All these measurements were carried out in the semirecumbent position at 30 degrees. We continuously recorded electrocardiogram, heart rate, pulse oximetry, and invasive systemic blood pressure.Measurements and proceduresMaximal inspiratory and expiratory pressureMuscular respiratory strength was assessed with the PImax and PEmax measurements. PImax and PEmax were measured, after 1–2min of spontaneous breathing, with an external pressure transducer via a unidirectional valve (Hans Rudolph, Kansas City, MO) connected to the endotracheal tube. PImax was obtained at residual volume, by occluding the inspiratory port of the unidirectional valve, whereas PEmax was measured at total lung volume, by occluding the expiratory port.<a class="elsevierStyleCrossRef" href="#bib0080">16</a> After 20–25s of occluded inspiration or expiration, the most negative or positive pressure values were recorded for PImax or PEmax test. Two measurements were performed and the highest value was used for analysis.CO2 response testTo increase the CO2 we used the method of the re-inhalation of expired air<a class="elsevierStyleCrossRefs" href="#bib0065">13,17</a> by inserting a corrugated tube between the Y-piece and the endotracheal tube that increased the dead space with a volume similar to the tidal volume (VT) obtained with a pressure support of 7cm H2O in each patient. The increase of dead space was made with a continuous corrugated tube (CORR-A-FLEX II® 22mm Tubing, Hudson RCI®, Temecula, USA).Baseline values for CO2 response test were obtained after applying 5min of pressure support ventilation with a pressure of 7cm H2O without PEEP, and FiO2 was set at 1.0 to prevent hypoxemia for patients’ security and to avoid hypoxic stimuli. Then, respiratory rate, airway occlusion pressure 0.1s after the beginning of inspiration (P0.1), and minute volume (VE) were recorded from the ventilator, and an arterial blood sample was withdrawn. Thereafter, we initiated the CO2 response test by increasing dead space maintaining the same ventilatory support, and when the exhaled CO2 (measured through capnography) had increased by above 10mm Hg, we measured again the respiratory rate, P0.1 and VE, and withdrew another arterial blood sample. Once the CO2 response test was finished the added dead space was removed and the patient was returned to his original assisted ventilation mode.We studied the following derived indexes of CO2 response test: the hypercapnic ventilatory response (ΔVE/ΔPaCO2), defined as the ratio of the change in VE (ΔVE) to the change in PaCO2 (ΔPaCO2) and the hypercapnic drive response (ΔP0.1/ΔPaCO2), defined as the ratio of the change in P0.1 (ΔP0.1) to ΔPaCO2. The changes in VE, P0.1, and PaCO2 were calculated as the difference between the value at the end of the CO2 response test and the baseline value. P0.1 was measured by means of the built-in system of the Dräger ventilator (Evita 2 Dura or Evita 4, Dräger, Lübeck, Germany),<a class="elsevierStyleCrossRefs" href="#bib0090">18,19</a> and P0.1 was calculated as the mean of 5 measurements at each point of the study. Arterial blood gases were measured with a blood gas analyzer (IL-1650, Instrument Laboratory, Izasa, Spain).Data collection and definitionsWe recorded the following clinical variables: gender, age, height, weight, the Simplified Acute Physiological Score (SAPS) II, length of mechanical ventilation before the study day, ICU and in-hospital length of stay, and in-hospital mortality.We considered the study day as the day that the CO2 response test was performed. Length of mechanical ventilation before the study day was defined as the number of days between the beginning of mechanical ventilation and the day the CO2 response test was performed. Patients were followed-up until discharge from our two hospitals.Statistical analysisCategorical data are expressed as number and percentages. Continuous variables are expressed as mean±standard deviation or as median and interquartile ranges (IQR). Differences between groups were compared with t test and chi-square test. Non-COPD and COPD patients were grouped into tertiles according to the baseline level of plasma bicarbonate concentration. Trend analysis among the tertiles of plasma bicarbonate concentration and changes of pH by changes of PaCO2, minute volume, CO2 response, tidal volume and respiratory rate, were conducted with Jonckheere–Terpstra test. Statistical analysis was performed with specific statistics software (SPSS 19.0, SPSS, Chicago, IL).ResultsOne hundred and sixty-eight patients were studied, 120 patients in the non-COPD group and 48 in the COPD group. The COPD group had a mean FEV1/FVC ratio of 54±12% and of the FEV1 of 37±16%. Compared with non-COPD patients, COPD patients were mostly men, with higher body mass index and lower severity disease (<a class="elsevierStyleCrossRef" href="#tbl0005">Table 1</a>). The main diagnoses of non-COPD patients were pneumonia and non-pulmonary sepsis (<a class="elsevierStyleCrossRef" href="#tbl0005">Table 1</a>). Non-COPD patients had longer duration of ventilation before the study day, and longer ICU and in-hospital length of stay (<a class="elsevierStyleCrossRef" href="#tbl0005">Table 1</a>).<elsevierMultimedia ident="tbl0005"></elsevierMultimedia>Between non-COPD and COPD groups there was no difference in the added dead space used to increase the PaCO2. Mean values were 414±70mL and 392±68mL respectively (p=0.08). The baseline values of CO2 response test, with pressure support ventilation of 7cm H2O and FiO2 of 1.0 showed a higher plasma bicarbonate concentration and PaCO2 and lower minute volume, respiratory rate and pH in COPD group compared with the non-COPD group (<a class="elsevierStyleCrossRef" href="#tbl0010">Table 2</a>). No differences were found in mean PaO2 and baseline P0.1 values between groups (<a class="elsevierStyleCrossRef" href="#tbl0010">Table 2</a>). The ventilatory and central CO2 response was lower in COPD patients than in non-COPD. No differences were found in respiratory muscle strength assessed by PImax and PEmax between groups (<a class="elsevierStyleCrossRef" href="#tbl0010">Table 2</a>).<elsevierMultimedia ident="tbl0010"></elsevierMultimedia>The tertile ranges of plasma bicarbonate concentration were 17.1 to 24.1, 24.1 to 26.6 and 26.6 to 37.5mmol/L for non-COPD patients, and 19.7 to 30.9, 30.9 to 35.5 and 35.5 to 43.7mmol/L for COPD patients. We found a significant inverse linear relationship between plasma bicarbonate concentration grouped in tertiles, in non-COPD and COPD groups of patients, and baseline minute volume (p<0.001) (<a class="elsevierStyleCrossRef" href="#fig0005">Fig. 1</a>). The same inverse linear relationship in both groups of patients were found between the tertiles of plasma bicarbonate concentration and pH change per mm Hg of PaCO2induced by CO2response test (p<0.001) (<a class="elsevierStyleCrossRef" href="#fig0010">Fig. 2</a>), and between the tertiles of plasma bicarbonate concentration and hypercapnic ventilatory response (p<0.001) and hypercapnic drive response (p<0.001) (<a class="elsevierStyleCrossRef" href="#fig0015">Fig. 3</a>).<elsevierMultimedia ident="fig0005"></elsevierMultimedia><elsevierMultimedia ident="fig0010"></elsevierMultimedia><elsevierMultimedia ident="fig0015"></elsevierMultimedia>When plotted minute volume and P0.1 against PaCO2, in non-COPD and COPD patients grouped by tertiles of plasma bicarbonate concentration, the slope of the CO2 response flattened with high levels of plasma bicarbonate concentration (<a class="elsevierStyleCrossRef" href="#fig0020">Fig. 4</a>). Of note, baseline values of minute volume decreased with the increased level of plasma bicarbonate, without changes in P0.1. Minute volume decreases through decrease in tidal volume (p=0.003) and respiratory frequency (P<0.001) (<a class="elsevierStyleCrossRef" href="#fig0025">Fig. 5</a>).<elsevierMultimedia ident="fig0020"></elsevierMultimedia><elsevierMultimedia ident="fig0025"></elsevierMultimedia>DiscussionIn this study we found an inverse relationship between the plasma bicarbonate concentration and the variation in pH for a given change in PaCO2. Indeed, the most interesting finding was that the response to CO2 also inversely depends on the level of plasma bicarbonate concentration, both in non-COPD and COPD patients, during the weaning of mechanical ventilation.These results are in agreement with previous studies in healthy subjects<a class="elsevierStyleCrossRefs" href="#bib0015">3,4</a> and chronic hypercapnia secondary to kyphoscoliosis or skeletal muscle disease.<a class="elsevierStyleCrossRefs" href="#bib0025">5,6</a> In these studies the variations in plasma bicarbonate concentration were induced by oral administration of sodium bicarbonate and ethacrynic acid, or ammonium chloride. Our results are also in accordance with a previous study with obesity-hypoventilation syndrome patients during the weaning of mechanical ventilation.<a class="elsevierStyleCrossRef" href="#bib0060">12</a> In that study we found the same inverse relationship between plasma bicarbonate concentration and CO2 response. We also found that lowering plasma bicarbonate concentration by acetazolamide administration increased the CO2 response in a small subset of patients.<a class="elsevierStyleCrossRef" href="#bib0060">12</a>One possible explanation for several previous studies that did not find the relationship between the plasma bicarbonate concentration and CO2 response was that the changes in the bicarbonate concentrations were small and in some cases only toward acidosis.<a class="elsevierStyleCrossRefs" href="#bib0035">7–11</a> Changes in the slope of the CO2 response are more evident when the patients reach high levels of plasma bicarbonate concentration, as occurred in our study.The ventilatory adaptation to an increase of plasma bicarbonate concentration is primarily achieved by decrease of tidal volume in subjects without lung disease,<a class="elsevierStyleCrossRef" href="#bib0030">6</a> while we found a decrease in both tidal volume and respiratory rate. This discordance may be related with the fact that they were studied with a pressure support of 7cm H2O. Indeed, Brochard et al.<a class="elsevierStyleCrossRef" href="#bib0100">20</a> found that the ventilation with a pressure support of 10cm H2O during weaning of mechanical ventilation resulted in significant improvements in tidal volume with a decreased respiratory rate compared to spontaneous ventilation.The clinical significance of this relationship between the level of plasma bicarbonate concentration and baseline minute volume and CO2 response relies on the fact that modifying the plasma bicarbonate concentration we can change the baseline minute volume, the CO2 response, and the work of breathing. Thus, in patients with COPD we could increase the minute volume and the CO2 response by reducing the plasma bicarbonate concentration. Reducing elevated levels of plasma bicarbonate concentration is simple with the administration of acetazolamide, as observed in our study of patients with obesity-hypoventilation syndrome.<a class="elsevierStyleCrossRef" href="#bib0060">12</a> Ongoing clinical trials evaluating the use of acetazolamide to facilitate the weaning of mechanical ventilation will address this issue. However, one must bear in mind several issues when considering this potential treatment. First, when reducing elevated plasma bicarbonate concentration there is an inherent risk of increasing the work of breathing in excess. Second, in non-COPD patients ventilated with high minute volume and with difficulty of weaning of mechanical ventilation, increasing the plasma bicarbonate concentration can reduce the minute volume and therefore the work of breathing.Along with the plasma bicarbonate concentration, the CO2 response depends on other factors such as the family,<a class="elsevierStyleCrossRef" href="#bib0105">21</a> age,<a class="elsevierStyleCrossRef" href="#bib0110">22</a> and circadian rhythm.<a class="elsevierStyleCrossRef" href="#bib0115">23</a> In this regard, we note that approximately 15% of healthy subjects have decreased response to CO2. These individuals are likely to develop CO2 retention when additional respiratory problems arise, such as obesity, obstructive lung disease or status asthmaticus.<a class="elsevierStyleCrossRefs" href="#bib0105">21,24,25</a> The reduced CO2 response in COPD patients cannot be attributed to hyperoxia. In these patients, the increase in the PaCO2 by hyperoxia is due to changes in the ventilation-perfusion distribution<a class="elsevierStyleCrossRefs" href="#bib0130">26,27</a> and to the increase in dead space by the Haldane effect on PaCO2.<a class="elsevierStyleCrossRef" href="#bib0140">28</a>Likewise, the high PaO2observed in our patients may be explained by the FiO2of 1 used in the study to correct hypoxemia in all lung units regardless of their ventilation-perfusion ratio except with a pure shunt.The main limitation of this study was the difficulty to interpret the results of the CO2 response tests due to the wide range of normal values in healthy subjects.<a class="elsevierStyleCrossRefs" href="#bib0145">29,30</a> In addition, the coefficients of variation are also wide, from 17.9% for the ventilatory response (ranged from 8.3 to 26.3%)<a class="elsevierStyleCrossRef" href="#bib0155">31</a> and about 60% for the P0.1 during CO2 rebreathing trials.<a class="elsevierStyleCrossRef" href="#bib0160">32</a> Other limitations of our study were the way in which we measured CO2 response with the ventilator, instead of with the conventional method.<a class="elsevierStyleCrossRef" href="#bib0165">33</a> The Evita ventilator tends to overestimate high P0.1 values and to underestimate low P0.1 values.<a class="elsevierStyleCrossRef" href="#bib0095">19</a> Another possible limitation is air trapping due to the high minute volume that occurs with hypercapnic stimulation or by effect of bronchoconstriction in patients with COPD. However, Conti et al.<a class="elsevierStyleCrossRef" href="#bib0170">34</a> found that reliable measurement of P0.1 can be obtained during pressure-support ventilation in patients with variable levels of intrinsic PEEP.In conclusion, we observed an inverse relationship between the plasma bicarbonate concentration and the variation in hydrogen ion concentration for a given change in PaCO2, and we found that elevated levels of plasma bicarbonate reduced the CO2 response both in COPD and non-COPD critically ill patients during weaning of mechanical ventilation.Conflict of interestAll authors declare that they have no conflict of interest." "textoCompletoSecciones" => array:1 [ "secciones" => array:11 [ 0 => array:2 [ "identificador" => "xres334292" "titulo" => array:9 [ 0 => "Abstract" 1 => "Objective" 2 => "Design" 3 => "Setting" 4 => "Patients" 5 => "Interventions" 6 => "Main outcome measures" 7 => "Results" 8 => "Conclusions" ] ] 1 => array:2 [ "identificador" => "xpalclavsec316022" "titulo" => "Keywords" ] 2 => array:2 [ "identificador" => "xres334291" "titulo" => array:9 [ 0 => "Resumen" 1 => "Objetivo" 2 => "Diseño" 3 => "Ámbito" 4 => "Pacientes" 5 => "Intervenciones" 6 => "Variables de interés principales" 7 => "Resultados" 8 => "Conclusiones" ] ] 3 => array:2 [ "identificador" => "xpalclavsec316021" "titulo" => "Palabras clave" ] 4 => array:2 [ "identificador" => "sec0005" "titulo" => "Introduction" ] 5 => array:3 [ "identificador" => "sec0010" "titulo" => "Methods" "secciones" => array:4 [ 0 => array:2 [ "identificador" => "sec0015" "titulo" => "Patients" ] 1 => array:2 [ "identificador" => "sec0020" "titulo" => "Protocol" ] 2 => array:3 [ "identificador" => "sec0025" "titulo" => "Measurements and procedures" "secciones" => array:2 [ 0 => array:2 [ "identificador" => "sec0030" "titulo" => "Maximal inspiratory and expiratory pressure" ] 1 => array:2 [ "identificador" => "sec0035" "titulo" => "CO response test" ] ] ] 3 => array:2 [ "identificador" => "sec0040" "titulo" => "Data collection and definitions" ] ] ] 6 => array:2 [ "identificador" => "sec0045" "titulo" => "Statistical analysis" ] 7 => array:2 [ "identificador" => "sec0050" "titulo" => "Results" ] 8 => array:2 [ "identificador" => "sec0055" "titulo" => "Discussion" ] 9 => array:2 [ "identificador" => "sec0060" "titulo" => "Conflict of interest" ] 10 => array:1 [ "titulo" => "References" ] ] ] "pdfFichero" => "main.pdf" "tienePdf" => true "fechaRecibido" => "2013-07-30" "fechaAceptado" => "2013-10-22" "PalabrasClave" => array:2 [ "en" => array:1 [ 0 => array:4 [ "clase" => "keyword" "titulo" => "Keywords" "identificador" => "xpalclavsec316022" "palabras" => array:5 [ 0 => "Hypercapnia" 1 => "Bicarbonate" 2 => "Chronic obstructive pulmonary disease" 3 => "Mechanical ventilation" 4 => "Respiratory center" ] ] ] "es" => array:1 [ 0 => array:4 [ "clase" => "keyword" "titulo" => "Palabras clave" "identificador" => "xpalclavsec316021" "palabras" => array:5 [ 0 => "Hipercapnia" 1 => "Bicarbonato" 2 => "Enfermedad pulmonar obstructiva crónica" 3 => "Ventilación mecánica" 4 => "Centro respiratorio" ] ] ] ] "tieneResumen" => true "resumen" => array:2 [ "en" => array:2 [ "titulo" => "Abstract" "resumen" => "ObjectiveThere is controversy about the effects of high plasma bicarbonate concentration ([HCO3−]) and the CO2 response test. We analyzed the relationship between [HCO3−] and the variation in hydrogen ion concentration (pH) for a given change in PaCO2, and its effects upon CO2 response. DesignA retrospective study was carried out. SettingTwo intensive care units. PatientsSubjects with and without chronic obstructive pulmonary disease (COPD), at the beginning of weaning from mechanical ventilation. InterventionsThe CO2 response was evaluated by the re-inhalation of expired air method, measuring the hypercapnic ventilatory response (ΔVE/ΔPaCO2) and hypercapnic drive response (ΔP01/ΔPaCO2), where VE is minute volume and P0.1 is airway occlusion pressure 0.1s after the initiation of inspiration. Main outcome measures[HCO3−] and CO2 response. ResultsA total of 120 patients in the non-COPD group and 48 in the COPD group were studied. COPD patients had higher mean [HCO3−] than non-COPD patients (33.2±5.4 vs. 25.7±3.7mmol/l, p<0.001). In both non-COPD and COPD patients we observed a significant inverse linear relationship between [HCO3−] and pH change per mmHg of PaCO2 (p<0.001), ΔVE/ΔPaCO2 (p<0.001) and ΔP0.1/ΔPaCO2 (p<0.001). ConclusionsThere is an inverse linear relationship between [HCO3−] and the variation of pH for a given change in PaCO2 and the CO2 response." ] "es" => array:2 [ "titulo" => "Resumen" "resumen" => "ObjetivoExiste controversia en si las diferencias en la concentración plasmática de bicarbonato (CO3H−) modifican la respuesta al incremento de CO2. Hemos analizado la relación entre la CO3H− y la variación en la concentración de iones de hidrógeno (pH) por un incremento agudo de la PaCO2 y entre la CO3H− y la respuesta del sistema respiratorio al incremento de CO2. DiseñoEstudio retrospectivo. ÁmbitoDos unidades de cuidados intensivos. PacientesPacientes con y sin enfermedad pulmonar obstructiva crónica (EPOC) en el inicio de la desconexión de ventilación mecánica. IntervencionesLa respuesta del sistema respiratorio al incremento de CO2 fue evaluada por el método de reinhalación del aire espirado, midiendo la respuesta ventilatoria a la hipercapnia (ΔVE/ΔPaCO2) y la respuesta del centro respiratorio a la hipercapnia (ΔP0,1/ΔPaCO2), donde VE es el volumen minuto y P0,1 es la presión de oclusión de la vía aérea a 0,1 s del inicio de la inspiración. Variables de interés principalesCO3H− y respuesta al CO2. ResultadosFueron estudiados 120 pacientes sin EPOC y 48 con EPOC. Las CO3H− medias en los pacientes sin y con EPOC fueron de 25,7±3,7 y 33,2±5,4 mmol/L, respectivamente (p<0,001). Hallamos, en ambos grupos de pacientes, una relación linear inversa entre la CO3H− y el cambio de pH por mmHg de PaCO2 (p<0,001), el ΔVE/ΔPaCO2 (p<0,001) y el ΔP0,1/ΔPaCO2 (p<0,001). ConclusionesHay una relación linear inversa entre la CO3H− y la variación en el pH por un incremento agudo de la PaCO2 y entre la CO3H− y la respuesta al CO2." ] ] "multimedia" => array:7 [ 0 => array:7 [ "identificador" => "fig0005" "etiqueta" => "Figure 1" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr1.jpeg" "Alto" => 1060 "Ancho" => 1379 "Tamanyo" => 61934 ] ] "descripcion" => array:1 [ "en" => "Relationship between plasma bicarbonate concentration grouped in tertiles and baseline minute volume expressed by body weight in mL/min/kg, in non-COPD (white circles) and COPD patients (black circles). Dashed lines show the linear relationship among groups (p<0.001 for each variable). Values are expressed as mean and standard error." ] ] 1 => array:7 [ "identificador" => "fig0010" "etiqueta" => "Figure 2" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr2.jpeg" "Alto" => 1028 "Ancho" => 1402 "Tamanyo" => 66378 ] ] "descripcion" => array:1 [ "en" => "Relationship between plasma bicarbonate concentration grouped in tertiles and pH change per mm Hg of PaCO2, in non-COPD (white circles) and COPD patients (black circles). Dashed lines show the linear relationship among groups (p<0.001). Values are expressed as mean and standard error." ] ] 2 => array:7 [ "identificador" => "fig0015" "etiqueta" => "Figure 3" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr3.jpeg" "Alto" => 2427 "Ancho" => 1583 "Tamanyo" => 146713 ] ] "descripcion" => array:1 [ "en" => "Relationship between plasma bicarbonate concentration grouped in tertiles and hypercapnic ventilatory response (ΔVE/ΔPaCO2) (top), and hypercapnic drive response (ΔP0.1/ΔPaCO2) (bottom), in non-COPD (white circles) and COPD patients (black circles). Dashed lines show the linear relationship among groups (p<0.001 for each variable). Values are expressed as mean and standard error." ] ] 3 => array:7 [ "identificador" => "fig0020" "etiqueta" => "Figure 4" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr4.jpeg" "Alto" => 2453 "Ancho" => 1546 "Tamanyo" => 182187 ] ] "descripcion" => array:1 [ "en" => "Baseline and response to CO2 increase of minute volume (VE) and occlusion pressure (P0.1). The patients were grouped according to tertiles of bicarbonate concentration, in non-COPD (white circles) and COPD patients (black circles). Values are expressed as mean and standard error." ] ] 4 => array:7 [ "identificador" => "fig0025" "etiqueta" => "Figure 5" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr5.jpeg" "Alto" => 2478 "Ancho" => 1594 "Tamanyo" => 151447 ] ] "descripcion" => array:1 [ "en" => "Relationship between plasma bicarbonate concentration grouped in tertiles and tidal volume (VT) in mL/kg of body weight and respiratory rate in breath per minute (bpm), in non-COPD (white circles) and COPD patients (black circles). Dashed lines show the linear relationship among groups. Values are expressed as mean and standard error." ] ] 5 => array:7 [ "identificador" => "tbl0005" "etiqueta" => "Table 1" "tipo" => "MULTIMEDIATABLA" "mostrarFloat" => true "mostrarDisplay" => false "tabla" => array:3 [ "leyenda" => "SAPS: simplified acute physiology score; COPD: chronic obstructive pulmonary disease." "tablatextoimagen" => array:1 [ 0 => array:2 [ "tabla" => array:1 [ 0 => """ <table border="0" frame="\n \t\t\t\t\tvoid\n \t\t\t\t" class=""><thead title="thead"><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-head\n \t\t\t\t " align="" valign="\n \t\t\t\t\ttop\n \t\t\t\t" style="border-bottom: 2px solid black"> \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-head\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t" style="border-bottom: 2px solid black">Non-COPD N: 120 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-head\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t" style="border-bottom: 2px solid black">COPD n: 48 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-head\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t" style="border-bottom: 2px solid black">p value \t\t\t\t\t\t\n \t\t\t\t</td></tr></thead><tbody title="tbody"><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Age, years \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">61±14 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">65±9 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">0.054 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Gender, female, n (%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">49 (40.8%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">6 (12.5%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t"><0.001 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Weight, kg \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">75±17 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">86±23 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">0.005 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Height, cm \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">165±9 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">165±8 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">0.97 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Body mass index, kg/m2 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">27.8±6.4 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">31.9±8.6 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">0.004 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">SAPS II at ICU admission \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">41±12 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">36±11 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">0.02 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " colspan="4" align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t"></td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " colspan="4" align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Main diagnosis, n (%)</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Pneumonia \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">52 (43.3%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">2 (4.2%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="" valign="\n \t\t\t\t\ttop\n \t\t\t\t"> \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Non-pulmonary sepsis \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">37 (30.8%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">– \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="" valign="\n \t\t\t\t\ttop\n \t\t\t\t"> \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Postoperative state \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">19 (15.8%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">4 (8.3%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="" valign="\n \t\t\t\t\ttop\n \t\t\t\t"> \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Other \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">12 (10.0%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">– \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="" valign="\n \t\t\t\t\ttop\n \t\t\t\t"> \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Exacerbated COPD \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">– \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">42 (87.5%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="" valign="\n \t\t\t\t\ttop\n \t\t\t\t"> \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Length of ventilation before study day, days<a class="elsevierStyleCrossRef" href="#tblfn0005">*</a> \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">12.5 (7–20) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">4 (3–6) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t"><0.001 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Length of weaning, days<a class="elsevierStyleCrossRef" href="#tblfn0005">*</a> \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">1 (0–7) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">1 (0–5) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t"><0.001 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">ICU LOS, days<a class="elsevierStyleCrossRef" href="#tblfn0005">*</a> \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">22 (13–40) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">7 (5–14) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">0.38 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">In-hospital LOS, days<a class="elsevierStyleCrossRef" href="#tblfn0005">*</a> \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">46 (29–75) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">21 (13–29) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t"><0.001 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">In-hospital mortality, n (%) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">32 (26.7) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">9 (18.8) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t"><0.001 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="" valign="\n \t\t\t\t\ttop\n \t\t\t\t"> \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="" valign="\n \t\t\t\t\ttop\n \t\t\t\t"> \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="" valign="\n \t\t\t\t\ttop\n \t\t\t\t"> \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">0.32 \t\t\t\t\t\t\n \t\t\t\t</td></tr></tbody></table> """ ] "imagenFichero" => array:1 [ 0 => "xTab491857.png" ] ] ] "notaPie" => array:1 [ 0 => array:3 [ "identificador" => "tblfn0005" "etiqueta" => "*" "nota" => "Median (IQR). ICU: intensive care unit; LOS: length of stay." ] ] ] "descripcion" => array:1 [ "en" => "Clinical characteristics of 168 patients." ] ] 6 => array:7 [ "identificador" => "tbl0010" "etiqueta" => "Table 2" "tipo" => "MULTIMEDIATABLA" "mostrarFloat" => true "mostrarDisplay" => false "tabla" => array:2 [ "leyenda" => "COPD: chronic obstructive pulmonary disease; P0.1: occlusion pressure at 100ms; ΔVE/ΔPaCO2: hypercapnic ventilatory response; ΔP0.1/ΔPaCO2: hypercapnic drive response; PImax: maximal inspiratory pressure; PEmax: maximal expiratory pressure." "tablatextoimagen" => array:1 [ 0 => array:2 [ "tabla" => array:1 [ 0 => """ <table border="0" frame="\n \t\t\t\t\tvoid\n \t\t\t\t" class=""><thead title="thead"><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-head\n \t\t\t\t " align="" valign="\n \t\t\t\t\ttop\n \t\t\t\t" style="border-bottom: 2px solid black"> \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-head\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t" style="border-bottom: 2px solid black">Non-COPD n: 120 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-head\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t" style="border-bottom: 2px solid black">COPD n: 48 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-head\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t" style="border-bottom: 2px solid black">p value \t\t\t\t\t\t\n \t\t\t\t</td></tr></thead><tbody title="tbody"><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " colspan="4" align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">CO2response test</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Baseline PaO2 at FiO2 of 1.0, mm Hg \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">439±100 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">410±114 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">0.10 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Baseline CO3H mmol/L \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">25.7±3.7 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">33.2±5.4 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t"><0.001 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " colspan="4" align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t"></td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " colspan="4" align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">pH</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Baseline \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">7.42±0.05 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">7.38±0.05 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t"><0.001 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Hypercapnia \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">7.31±0.05 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">7.29±0.05 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">0.02 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " colspan="4" align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t"></td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " colspan="4" align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">PaCO2, mm Hg</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Baseline \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">39.6±7.4 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">56.1±12.3 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t"><0.001 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Hypercapnia \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">55.6±10.2 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">73.2±15.1 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t"><0.001 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " colspan="4" align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t"></td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " colspan="4" align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Respiratory rate, bpm</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Baseline \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">28±7.3 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">23±6.0 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t"><0.001 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Hypercapnia \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">34±7.4 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">28±7.8 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t"><0.001 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " colspan="4" align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t"></td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " colspan="4" align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Minute ventilation, L/min</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Baseline \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">11.2±3.2 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">9.0±2.5 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t"><0.001 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Hypercapnia \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">18.3±4.9 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">13.4±4.1 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t"><0.001 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " colspan="4" align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t"></td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " colspan="4" align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">P0.1, cm H2O</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Baseline \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">3.2±1.9 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">2.9±1.6 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">0.32 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Hypercapnia \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">9.7±3.9 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">7.0±3.1 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t"><0.001 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">ΔVE/ΔPaCO2, L/min/mm Hg \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">0.52±0.37 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">0.30±0.20 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t"><0.001 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">ΔP0.1/ΔPaCO2, cm H2O/mm Hg \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">0.44±0.26 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">0.27±0.18 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t"><0.001 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " colspan="4" align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t"></td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " colspan="4" align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">Respiratory muscle strength</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">PImax, cm H2O \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">46±18 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">47±14 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">0.80 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="left" valign="\n \t\t\t\t\ttop\n \t\t\t\t">PEmax, cm H2O \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">26±13 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">27±13 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="\n \t\t\t\t\ttable-entry\n \t\t\t\t " align="char" valign="\n \t\t\t\t\ttop\n \t\t\t\t">0.57 \t\t\t\t\t\t\n \t\t\t\t</td></tr></tbody></table> """ ] "imagenFichero" => array:1 [ 0 => "xTab491858.png" ] ] ] ] "descripcion" => array:1 [ "en" => "CO2 response test (baseline and hypercapnia values of arterial blood gases and ventilatory parameters) and respiratory muscle strength (PEmax and PImax values)." ] ] ] "bibliografia" => array:2 [ "titulo" => "References" "seccion" => array:1 [ 0 => array:2 [ "identificador" => "bibs0005" "bibliografiaReferencia" => array:34 [ 0 => array:3 [ "identificador" => "bib0005" "etiqueta" => "1" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Incidence of metabolic alkalemia in hospitalized patients" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:3 [ 0 => "J.E. Hodgkin" 1 => "F.F. Soeprono" 2 => "D.M. Chan" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:7 [ "tituloSerie" => "Crit Care Med" "fecha" => "1980" "volumen" => "8" "paginaInicial" => "725" "paginaFinal" => "728" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/6778655" "web" => "Medline" ] ] "itemHostRev" => array:3 [ "pii" => "S0140673600028440" "estado" => "S300" "issn" => "01406736" ] ] ] ] ] ] ] 1 => array:3 [ "identificador" => "bib0010" "etiqueta" => "2" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Determinants of blood pH in health and disease" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:1 [ 0 => "J.A. Kellum" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1186/cc644" "Revista" => array:7 [ "tituloSerie" => "Crit Care" "fecha" => "2000" "volumen" => "4" "paginaInicial" => "6" "paginaFinal" => "14" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/11094491" "web" => "Medline" ] ] "itemHostRev" => array:3 [ "pii" => "S0735109705023417" "estado" => "S300" "issn" => "07351097" ] ] ] ] ] ] ] 2 => array:3 [ "identificador" => "bib0015" "etiqueta" => "3" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Respiration in man during metabolic alkalosis" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:1 [ 0 => "D.J. Stone" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:6 [ "tituloSerie" => "J Appl Physiol" "fecha" => "1962" "volumen" => "17" "paginaInicial" => "33" "paginaFinal" => "37" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/13917462" "web" => "Medline" ] ] ] ] ] ] ] ] 3 => array:3 [ "identificador" => "bib0020" "etiqueta" => "4" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Compensatory hypoventilation in metabolic alkalosis" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:4 [ 0 => "S. Javaheri" 1 => "N.S. Shore" 2 => "B. Rose" 3 => "H. Kazemi" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:6 [ "tituloSerie" => "Chest" "fecha" => "1982" "volumen" => "81" "paginaInicial" => "296" "paginaFinal" => "301" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/6799256" "web" => "Medline" ] ] ] ] ] ] ] ] 4 => array:3 [ "identificador" => "bib0025" "etiqueta" => "5" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Respiratory-renal adjustments in chronic hypercapnia in man. Extracellular bicarbonate concentration and the regulation of ventilation" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:3 [ 0 => "R.M. Goldring" 1 => "G.M. Turino" 2 => "H.O. Heinemann" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:6 [ "tituloSerie" => "Am J Med" "fecha" => "1971" "volumen" => "51" "paginaInicial" => "772" "paginaFinal" => "784" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/5129545" "web" => "Medline" ] ] ] ] ] ] ] ] 5 => array:3 [ "identificador" => "bib0030" "etiqueta" => "6" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Bicarbonate and the regulation of ventilation" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:2 [ 0 => "H.O. Heinemann" 1 => "R.M. Goldring" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:7 [ "tituloSerie" => "Am J Med" "fecha" => "1974" "volumen" => "57" "paginaInicial" => "361" "paginaFinal" => "370" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/4606269" "web" => "Medline" ] ] "itemHostRev" => array:3 [ "pii" => "S0735109706012630" "estado" => "S300" "issn" => "07351097" ] ] ] ] ] ] ] 6 => array:3 [ "identificador" => "bib0035" "etiqueta" => "7" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "The effect of maintained ammonium chloride acidosis on the relation between pulmonary ventilation and alveolar oxygen and carbon dioxide in man" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:4 [ 0 => "D.J. Cunningham" 1 => "D.G. Shaw" 2 => "S. Lahiri" 3 => "B.B. Lloyd" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:6 [ "tituloSerie" => "Q J Exp Physiol Cogn Med Sci" "fecha" => "1961" "volumen" => "46" "paginaInicial" => "323" "paginaFinal" => "334" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/13882641" "web" => "Medline" ] ] ] ] ] ] ] ] 7 => array:3 [ "identificador" => "bib0040" "etiqueta" => "8" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Respiratory control at high altitude suggesting active transport regulation of CSF pH" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:4 [ 0 => "J.W. Severinghaus" 1 => "R.A. Mitchell" 2 => "B.W. Richardson" 3 => "M.M. Singer" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:6 [ "tituloSerie" => "J Appl Physiol" "fecha" => "1963" "volumen" => "18" "paginaInicial" => "1155" "paginaFinal" => "1166" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/14080735" "web" => "Medline" ] ] ] ] ] ] ] ] 8 => array:3 [ "identificador" => "bib0045" "etiqueta" => "9" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Respiration and cerebrospinal fluid pH in metabolic acidosis and alkalosis" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:2 [ 0 => "R.A. Mitchell" 1 => "M.M. Singer" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:6 [ "tituloSerie" => "J Appl Physiol" "fecha" => "1965" "volumen" => "20" "paginaInicial" => "905" "paginaFinal" => "911" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/5837617" "web" => "Medline" ] ] ] ] ] ] ] ] 9 => array:3 [ "identificador" => "bib0050" "etiqueta" => "10" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Respiration and cerebral blood flow in metabolic acidosis and alkalosis in humans" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:3 [ 0 => "V. Fencl" 1 => "J.R. Vale" 2 => "J.A. Broch" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:6 [ "tituloSerie" => "J Appl Physiol" "fecha" => "1969" "volumen" => "27" "paginaInicial" => "67" "paginaFinal" => "76" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/5786972" "web" => "Medline" ] ] ] ] ] ] ] ] 10 => array:3 [ "identificador" => "bib0055" "etiqueta" => "11" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Relationship of CSF pH, O2, and CO2 responses in metabolic acidosis and alkalosis in humans" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:3 [ 0 => "G.B. Irsigler" 1 => "M.J. Stafford" 2 => "J.W. Severinghaus" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:6 [ "tituloSerie" => "J Appl Physiol" "fecha" => "1980" "volumen" => "48" "paginaInicial" => "355" "paginaFinal" => "361" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/6767670" "web" => "Medline" ] ] ] ] ] ] ] ] 11 => array:3 [ "identificador" => "bib0060" "etiqueta" => "12" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Hypercapnic respiratory failure in obesity-hypoventilation syndrome: CO(2) response and acetazolamide treatment effects" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:5 [ 0 => "J.M. Raurich" 1 => "G. Rialp" 2 => "J. Ibanez" 3 => "J.A. Llompart-Pou" 4 => "I. Ayestaran" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:6 [ "tituloSerie" => "Respir Care" "fecha" => "2010" "volumen" => "55" "paginaInicial" => "1442" "paginaFinal" => "1448" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/20979670" "web" => "Medline" ] ] ] ] ] ] ] ] 12 => array:3 [ "identificador" => "bib0065" "etiqueta" => "13" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Hypercapnia test as a predictor of success in spontaneous breathing trials and extubation" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:6 [ 0 => "J.M. Raurich" 1 => "G. Rialp" 2 => "J. Ibanez" 3 => "C. Campillo" 4 => "I. Ayestaran" 5 => "C. Blanco" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:6 [ "tituloSerie" => "Respir Care" "fecha" => "2008" "volumen" => "53" "paginaInicial" => "1012" "paginaFinal" => "1018" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/18655738" "web" => "Medline" ] ] ] ] ] ] ] ] 13 => array:3 [ "identificador" => "bib0070" "etiqueta" => "14" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Hypercapnia test and weaning outcome from mechanical ventilation in COPD patients" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:6 [ 0 => "J.M. Raurich" 1 => "G. Rialp" 2 => "J. Ibanez" 3 => "I. Ayestaran" 4 => "J.A. Llompart-Pou" 5 => "B. Togores" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:6 [ "tituloSerie" => "Anaesth Intensive Care" "fecha" => "2009" "volumen" => "37" "paginaInicial" => "726" "paginaFinal" => "732" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/19775035" "web" => "Medline" ] ] ] ] ] ] ] ] 14 => array:3 [ "identificador" => "bib0075" "etiqueta" => "15" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "CO2 response and duration of weaning from mechanical ventilation" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:5 [ 0 => "J.M. Raurich" 1 => "G. Rialp" 2 => "J. Ibanez" 3 => "J.A. Llompart-Pou" 4 => "I. Ayestaran" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.4187/respcare.01080" "Revista" => array:6 [ "tituloSerie" => "Respir Care" "fecha" => "2011" "volumen" => "56" "paginaInicial" => "1130" "paginaFinal" => "1136" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/21496366" "web" => "Medline" ] ] ] ] ] ] ] ] 15 => array:3 [ "identificador" => "bib0080" "etiqueta" => "16" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Estimation of inspiratory muscle strength in mechanically ventilated patients: the measurement of maximal inspiratory pressure" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:3 [ 0 => "J.J. Marini" 1 => "T.C. Smith" 2 => "V. Lamb" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "J Crit Care" "fecha" => "1986" "volumen" => "1" "paginaInicial" => "32" "paginaFinal" => "38" ] ] ] ] ] ] 16 => array:3 [ "identificador" => "bib0085" "etiqueta" => "17" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Ventilatory responses to dead space and CO2 breathing under inspiratory resistive load" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:2 [ 0 => "D.A. Sidney" 1 => "C.S. Poon" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:6 [ "tituloSerie" => "J Appl Physiol" "fecha" => "1995" "volumen" => "78" "paginaInicial" => "555" "paginaFinal" => "561" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/7759425" "web" => "Medline" ] ] ] ] ] ] ] ] 17 => array:3 [ "identificador" => "bib0090" "etiqueta" => "18" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "A new method for P0.1 measurement using standard respiratory equipment" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:6 [ 0 => "R. Kuhlen" 1 => "S. Hausmann" 2 => "D. Pappert" 3 => "K. Slama" 4 => "R. Rossaint" 5 => "K. Falke" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:6 [ "tituloSerie" => "Intensive Care Med" "fecha" => "1995" "volumen" => "21" "paginaInicial" => "554" "paginaFinal" => "560" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/7593896" "web" => "Medline" ] ] ] ] ] ] ] ] 18 => array:3 [ "identificador" => "bib0095" "etiqueta" => "19" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Evaluación de la medida de la presión de oclusión incorporada en los ventiladores Evita" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:5 [ 0 => "M. Subirana" 1 => "C. Irrazabal" 2 => "E. Bak" 3 => "F. Jara" 4 => "J. Mancebo" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "Med Intensiva" "fecha" => "1997" "volumen" => "21" "paginaInicial" => "305" "paginaFinal" => "310" ] ] ] ] ] ] 19 => array:3 [ "identificador" => "bib0100" "etiqueta" => "20" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Improved efficacy of spontaneous breathing with inspiratory pressure support" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:3 [ 0 => "L. Brochard" 1 => "F. Pluskwa" 2 => "F. Lemaire" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1164/ajrccm/136.2.411" "Revista" => array:6 [ "tituloSerie" => "Am Rev Respir Dis" "fecha" => "1987" "volumen" => "136" "paginaInicial" => "411" "paginaFinal" => "415" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/3619200" "web" => "Medline" ] ] ] ] ] ] ] ] 20 => array:3 [ "identificador" => "bib0105" "etiqueta" => "21" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Familial aspects of ventilatory control in patients with chronic obstructive pulmonary disease" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:3 [ 0 => "J.A. Fleetham" 1 => "M.E. Arnup" 2 => "N.R. Anthonisen" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1164/arrd.1984.129.2P2.S3" "Revista" => array:6 [ "tituloSerie" => "Am Rev Respir Dis" "fecha" => "1984" "volumen" => "129" "paginaInicial" => "3" "paginaFinal" => "7" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/6422810" "web" => "Medline" ] ] ] ] ] ] ] ] 21 => array:3 [ "identificador" => "bib0110" "etiqueta" => "22" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Effects of aging on ventilatory and occlusion pressure responses to hypoxia and hypercapnia" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:4 [ 0 => "D.D. Peterson" 1 => "A.I. Pack" 2 => "D.A. Silage" 3 => "A.P. Fishman" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1164/arrd.1981.124.4.387" "Revista" => array:6 [ "tituloSerie" => "Am Rev Respir Dis" "fecha" => "1981" "volumen" => "124" "paginaInicial" => "387" "paginaFinal" => "391" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/7294501" "web" => "Medline" ] ] ] ] ] ] ] ] 22 => array:3 [ "identificador" => "bib0115" "etiqueta" => "23" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "An endogenous circadian rhythm of respiratory control in humans" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:3 [ 0 => "C.M. Spengler" 1 => "C.A. Czeisler" 2 => "S.A. Shea" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:6 [ "tituloSerie" => "J Physiol" "fecha" => "2000" "volumen" => "526 Pt 3" "paginaInicial" => "683" "paginaFinal" => "694" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/10922018" "web" => "Medline" ] ] ] ] ] ] ] ] 23 => array:3 [ "identificador" => "bib0120" "etiqueta" => "24" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Effects of hypercapnia and inspiratory flow-resistive loading on respiratory activity in chronic airways obstruction" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:4 [ 0 => "M.D. Altose" 1 => "W.C. McCauley" 2 => "S.G. Kelsen" 3 => "N.S. Cherniack" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1172/JCI108665" "Revista" => array:6 [ "tituloSerie" => "J Clin Invest" "fecha" => "1977" "volumen" => "59" "paginaInicial" => "500" "paginaFinal" => "507" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/838862" "web" => "Medline" ] ] ] ] ] ] ] ] 24 => array:3 [ "identificador" => "bib0125" "etiqueta" => "25" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Hypoventilation in obstructive lung disease. The role of familial factors" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:3 [ 0 => "R. Mountain" 1 => "C. Zwillich" 2 => "J. Weil" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1056/NEJM197803092981001" "Revista" => array:6 [ "tituloSerie" => "N Engl J Med" "fecha" => "1978" "volumen" => "298" "paginaInicial" => "521" "paginaFinal" => "525" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/625307" "web" => "Medline" ] ] ] ] ] ] ] ] 25 => array:3 [ "identificador" => "bib0130" "etiqueta" => "26" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Hyperoxic-induced hypercapnia in stable chronic obstructive pulmonary disease" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:3 [ 0 => "C.S. Sassoon" 1 => "K.T. Hassell" 2 => "C.K. Mahutte" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:6 [ "tituloSerie" => "Am Rev Respir Dis" "fecha" => "1987" "volumen" => "135" "paginaInicial" => "907" "paginaFinal" => "911" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/3565937" "web" => "Medline" ] ] ] ] ] ] ] ] 26 => array:3 [ "identificador" => "bib0135" "etiqueta" => "27" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Effects of the administration of O2 on ventilation and blood gases in patients with chronic obstructive pulmonary disease during acute respiratory failure" "autores" => array:1 [ 0 => array:2 [ "etal" => true "autores" => array:6 [ 0 => "M. Aubier" 1 => "D. Murciano" 2 => "J. Milic-Emili" 3 => "E. Touaty" 4 => "J. Daghfous" 5 => "R. Pariente" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1164/arrd.1980.122.5.747" "Revista" => array:6 [ "tituloSerie" => "Am Rev Respir Dis" "fecha" => "1980" "volumen" => "122" "paginaInicial" => "747" "paginaFinal" => "754" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/6778278" "web" => "Medline" ] ] ] ] ] ] ] ] 27 => array:3 [ "identificador" => "bib0140" "etiqueta" => "28" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Contribution of the Haldane effect to the rise of arterial Pco2 in hypoxic patients breathing oxygen" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:4 [ 0 => "U.C. Luft" 1 => "E.M. Mostyn" 2 => "J.A. Loeppky" 3 => "M.D. Venters" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:6 [ "tituloSerie" => "Crit Care Med" "fecha" => "1981" "volumen" => "9" "paginaInicial" => "32" "paginaFinal" => "37" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/6780265" "web" => "Medline" ] ] ] ] ] ] ] ] 28 => array:3 [ "identificador" => "bib0145" "etiqueta" => "29" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Carbon dioxide response lines in young adults: the limits of the normal response" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:1 [ 0 => "G.B. Irsigler" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1164/arrd.1976.114.3.529" "Revista" => array:6 [ "tituloSerie" => "Am Rev Respir Dis" "fecha" => "1976" "volumen" => "114" "paginaInicial" => "529" "paginaFinal" => "536" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/970734" "web" => "Medline" ] ] ] ] ] ] ] ] 29 => array:3 [ "identificador" => "bib0150" "etiqueta" => "30" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Normal values for hypoxic and hypercapnic ventilatory drives in man" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:3 [ 0 => "C.A. Hirshman" 1 => "R.E. McCullough" 2 => "J.V. Weil" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:6 [ "tituloSerie" => "J Appl Physiol" "fecha" => "1975" "volumen" => "38" "paginaInicial" => "1095" "paginaFinal" => "1098" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/1141125" "web" => "Medline" ] ] ] ] ] ] ] ] 30 => array:3 [ "identificador" => "bib0155" "etiqueta" => "31" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Variability of ventilatory responses to hypoxia and hypercapnia" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:6 [ 0 => "S.A. Sahn" 1 => "C.W. Zwillich" 2 => "N. Dick" 3 => "R.E. McCullough" 4 => "S. Lakshminarayan" 5 => "J.V. Weil" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:6 [ "tituloSerie" => "J Appl Physiol" "fecha" => "1977" "volumen" => "43" "paginaInicial" => "1019" "paginaFinal" => "1025" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/606686" "web" => "Medline" ] ] ] ] ] ] ] ] 31 => array:3 [ "identificador" => "bib0160" "etiqueta" => "32" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Comparison of occlusion pressure and ventilatory responses" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:4 [ 0 => "D.H. Lederer" 1 => "M.D. Altose" 2 => "S.G. Kelsen" 3 => "N.S. Cherniack" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:6 [ "tituloSerie" => "Thorax" "fecha" => "1977" "volumen" => "32" "paginaInicial" => "212" "paginaFinal" => "220" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/867336" "web" => "Medline" ] ] ] ] ] ] ] ] 32 => array:3 [ "identificador" => "bib0165" "etiqueta" => "33" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Clinical characteristics, respiratory functional parameters, and outcome of a two-hour T-piece trial in patients weaning from mechanical ventilation" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:6 [ 0 => "I. Vallverdú" 1 => "N. Calaf" 2 => "M. Subirana" 3 => "A. Net" 4 => "S. Benito" 5 => "J. Mancebo" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1164/ajrccm.158.6.9712135" "Revista" => array:6 [ "tituloSerie" => "Am J Respir Crit Care Med" "fecha" => "1998" "volumen" => "158" "paginaInicial" => "1855" "paginaFinal" => "1862" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/9847278" "web" => "Medline" ] ] ] ] ] ] ] ] 33 => array:3 [ "identificador" => "bib0170" "etiqueta" => "34" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "A prospective, blinded evaluation of indexes proposed to predict weaning from mechanical ventilation" "autores" => array:1 [ 0 => array:2 [ "etal" => true "autores" => array:6 [ 0 => "G. Conti" 1 => "L. Montini" 2 => "M.A. Pennisi" 3 => "F. Cavaliere" 4 => "A. Arcangeli" 5 => "M.G. Bocci" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1007/s00134-004-2230-8" "Revista" => array:6 [ "tituloSerie" => "Intensive Care Med" "fecha" => "2004" "volumen" => "30" "paginaInicial" => "830" "paginaFinal" => "836" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/15127195" "web" => "Medline" ] ] ] ] ] ] ] ] ] ] ] ] ] "idiomaDefecto" => "en" "url" => "/02105691/0000003800000004/v1_201404270108/S0210569113002210/v1_201404270108/en/main.assets" "Apartado" => array:4 [ "identificador" => "24377" "tipo" => "SECCION" "en" => array:2 [ "titulo" => "Originales" "idiomaDefecto" => true ] "idiomaDefecto" => "en" ] "PDF" => "https://static.elsevier.es/multimedia/02105691/0000003800000004/v1_201404270108/S0210569113002210/v1_201404270108/en/main.pdf?idApp=WMIE&text.app=https://medintensiva.org/" "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/S0210569113002210?idApp=WMIE"]

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ORIGINAL

Respiratory CO2 response depends on plasma bicarbonate concentration in mechanically ventilated patients

La respuesta respiratoria al CO2 depende de la concentración plasmática de bicarbonato en pacientes sometidos a ventilación mecánica

G. Rialpa, J.M. Raurichb,

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joan.raurich@ssib.es

Corresponding author.

, J.A. Llompart-Poub, I. Ayestaránb, J. Ibáñezb

a Servei de Medicina Intensiva, Hospital Son Llàtzer, Palma de Mallorca, Illes Balears, Spain

b Servei de Medicina Intensiva, Hospital Universitari Son Espases, Palma de Mallorca, Illes Balears, Spain

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          "en" => "<p id="spar0085" class="elsevierStyleSimplePara elsevierViewall">Relationship between plasma bicarbonate concentration grouped in tertiles and baseline minute volume expressed by body weight in mL&#47;min&#47;kg&#44; in non-COPD &#40;white circles&#41; and COPD patients &#40;black circles&#41;&#46; Dashed lines show the linear relationship among groups &#40;<span class="elsevierStyleItalic">p</span><span class="elsevierStyleHsp" style=""></span>&#60;<span class="elsevierStyleHsp" style=""></span>0&#46;001 for each variable&#41;&#46; Values are expressed as mean and standard error&#46;</p>"
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    "textoCompleto" => "<span class="elsevierStyleSections"><span id="sec0005" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0105">Introduction</span><p id="par0005" class="elsevierStylePara elsevierViewall">Elevated plasma bicarbonate concentration is a relatively common entity in critically ill patients that can influence the process of weaning of mechanical ventilation&#46;<a class="elsevierStyleCrossRef" href="#bib0005"><span class="elsevierStyleSup">1</span></a> Several factors may contribute to elevated plasma bicarbonate concentration in critically ill patients&#44; such as chronic hypercapnia&#44; permissive hypercapnia in patients with acute respiratory distress syndrome&#44; the use of diuretics and steroids&#44; electrolyte disturbances &#40;hypochloremia&#44; hypokalemia&#41;&#44; and hypoalbuminemia&#44; among other factors&#46;<a class="elsevierStyleCrossRef" href="#bib0010"><span class="elsevierStyleSup">2</span></a></p><p id="par0010" class="elsevierStylePara elsevierViewall">Elevated plasma bicarbonate concentration may lead to compensatory hypoventilation and subsequent carbon dioxide &#40;CO<span class="elsevierStyleInf">2</span>&#41; retention to maintain acid-base homeostasis&#46; Also&#44; elevated plasma bicarbonate concentration can blunt the change in hydrogen ion concentration &#40;pH&#41; for a given change in the partial pressure of carbon dioxide &#40;PaCO<span class="elsevierStyleInf">2</span>&#41;&#44; in accordance with the Henderson-Hasselbalch relationship&#44; thereby blunting CO<span class="elsevierStyleInf">2</span> response&#46; In spite of this&#44; the effect of plasma bicarbonate concentration on CO<span class="elsevierStyleInf">2</span> response is controversial&#46; While some studies including a few number of healthy subjects or stable patients with chronic hypercapnia found that the ventilatory response to CO<span class="elsevierStyleInf">2</span> depends on the levels of plasma bicarbonate concentrations&#44;<a class="elsevierStyleCrossRefs" href="#bib0015"><span class="elsevierStyleSup">3&#8211;6</span></a> other studies found that the CO<span class="elsevierStyleInf">2</span> response was not affected by bicarbonate levels&#46;<a class="elsevierStyleCrossRefs" href="#bib0035"><span class="elsevierStyleSup">7&#8211;11</span></a></p><p id="par0015" class="elsevierStylePara elsevierViewall">To our knowledge&#44; the effect of plasma bicarbonate concentration on the CO<span class="elsevierStyleInf">2</span> response during mechanical ventilation has been studied only in patients with obesity-hypoventilation syndrome&#46;<a class="elsevierStyleCrossRef" href="#bib0060"><span class="elsevierStyleSup">12</span></a> If such a relationship between the plasma bicarbonate concentration and CO<span class="elsevierStyleInf">2</span> response is confirmed in a general population of critically ill patients&#44; normalizing elevated bicarbonate levels could be a useful tool to reduce the time of weaning of mechanical ventilation by increasing the CO<span class="elsevierStyleInf">2</span> response&#46; Whether the same occurs in chronic elevations of plasma bicarbonate levels&#44; as in patients with chronic obstructive pulmonary disease &#40;COPD&#41;&#44; and in acutely induced elevated plasma bicarbonate&#44; has not been addressed yet&#46;</p><p id="par0020" class="elsevierStylePara elsevierViewall">The objectives of this study were to analyze the relationship between the plasma bicarbonate concentration and the variation in pH for a given change in PaCO<span class="elsevierStyleInf">2</span> and to evaluate the effect of the level of plasma bicarbonate concentration on CO<span class="elsevierStyleInf">2</span> response in patients with and without COPD in the weaning of mechanical ventilation&#46;</p></span><span id="sec0010" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0110">Methods</span><span id="sec0015" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0115">Patients</span><p id="par0025" class="elsevierStylePara elsevierViewall">For the purpose of this analysis we selected cases from a database of patients with mechanical ventilation and CO<span class="elsevierStyleInf">2</span> response tests performed&#46; The patients were selected if the CO<span class="elsevierStyleInf">2</span> response test was performed on the first day of meeting criteria for a spontaneous breathing trial&#46; The patients were grouped in COPD and non-COPD&#46; COPD was diagnosed according pulmonary function tests by the forced expiratory volume in one second &#40;FEV1&#41; to forced vital capacity &#40;FVC&#41; ratio and the FEV1 expressed as percentage of predicted&#46; We excluded those patients admitted in the intensive care unit &#40;ICU&#41; with acute respiratory failure due to acute injury of the central nervous system&#44; neuromuscular disease or patients with chronic hypercapnia due to other reason than COPD&#46;</p><p id="par0030" class="elsevierStylePara elsevierViewall">Patients were retrospectively and non-consecutively studied in two medical-surgical ICUs&#44; at the beginning of the weaning of mechanical ventilation&#46; Hospital research committee approved the study&#46; Informed consent was obtained in all cases from patients or closest relatives&#46; Most of the patients of this study have been included in previous studies of our group&#46;<a class="elsevierStyleCrossRefs" href="#bib0065"><span class="elsevierStyleSup">13&#8211;15</span></a></p></span><span id="sec0020" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0120">Protocol</span><p id="par0035" class="elsevierStylePara elsevierViewall">Patients were studied when the physician in charge considered that they had clinical stability and fulfilled criteria for a spontaneous breathing trial&#46; These criteria included that the patient was hemodynamically stable&#44; without sedation awake and able to obey oral commands&#44; had core temperature below 38&#46;3<span class="elsevierStyleHsp" style=""></span>&#176;C and a ratio of the partial pressure of arterial oxygen &#40;PaO<span class="elsevierStyleInf">2</span>&#41; to the fraction of inspired oxygen &#40;FiO<span class="elsevierStyleInf">2</span>&#41; above 150<span class="elsevierStyleHsp" style=""></span>mm Hg with a positive end-expiratory pressure &#40;PEEP&#41; of &#8804;8<span class="elsevierStyleHsp" style=""></span>cm H<span class="elsevierStyleInf">2</span>O&#46;</p><p id="par0040" class="elsevierStylePara elsevierViewall">When the patients were clinically stable and ready for a spontaneous breathing trial&#44; respiratory neuromuscular function was evaluated by measurement of maximal inspiratory pressure &#40;P<span class="elsevierStyleInf">Imax</span>&#41;&#44; maximal expiratory pressure &#40;P<span class="elsevierStyleInf">Emax</span>&#41;&#44; and CO<span class="elsevierStyleInf">2</span> response test&#46; All these measurements were carried out in the semirecumbent position at 30 degrees&#46; We continuously recorded electrocardiogram&#44; heart rate&#44; pulse oximetry&#44; and invasive systemic blood pressure&#46;</p></span><span id="sec0025" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0125">Measurements and procedures</span><span id="sec0030" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0130">Maximal inspiratory and expiratory pressure</span><p id="par0045" class="elsevierStylePara elsevierViewall">Muscular respiratory strength was assessed with the P<span class="elsevierStyleInf">Imax</span> and P<span class="elsevierStyleInf">Emax</span> measurements&#46; P<span class="elsevierStyleInf">Imax</span> and P<span class="elsevierStyleInf">Emax</span> were measured&#44; after 1&#8211;2<span class="elsevierStyleHsp" style=""></span>min of spontaneous breathing&#44; with an external pressure transducer via a unidirectional valve &#40;Hans Rudolph&#44; Kansas City&#44; MO&#41; connected to the endotracheal tube&#46; P<span class="elsevierStyleInf">Imax</span> was obtained at residual volume&#44; by occluding the inspiratory port of the unidirectional valve&#44; whereas P<span class="elsevierStyleInf">Emax</span> was measured at total lung volume&#44; by occluding the expiratory port&#46;<a class="elsevierStyleCrossRef" href="#bib0080"><span class="elsevierStyleSup">16</span></a> After 20&#8211;25<span class="elsevierStyleHsp" style=""></span>s of occluded inspiration or expiration&#44; the most negative or positive pressure values were recorded for P<span class="elsevierStyleInf">Imax</span> or P<span class="elsevierStyleInf">Emax</span> test&#46; Two measurements were performed and the highest value was used for analysis&#46;</p></span><span id="sec0035" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0135">CO<span class="elsevierStyleInf">2</span> response test</span><p id="par0050" class="elsevierStylePara elsevierViewall">To increase the CO<span class="elsevierStyleInf">2</span> we used the method of the re-inhalation of expired air<a class="elsevierStyleCrossRefs" href="#bib0065"><span class="elsevierStyleSup">13&#44;17</span></a> by inserting a corrugated tube between the Y-piece and the endotracheal tube that increased the dead space with a volume similar to the tidal volume &#40;V<span class="elsevierStyleInf">T</span>&#41; obtained with a pressure support of 7<span class="elsevierStyleHsp" style=""></span>cm H<span class="elsevierStyleInf">2</span>O in each patient&#46; The increase of dead space was made with a continuous corrugated tube &#40;CORR-A-FLEX II<span class="elsevierStyleSup">&#174;</span> 22<span class="elsevierStyleHsp" style=""></span>mm Tubing&#44; Hudson RCI<span class="elsevierStyleSup">&#174;</span>&#44; Temecula&#44; USA&#41;&#46;</p><p id="par0055" class="elsevierStylePara elsevierViewall">Baseline values for CO<span class="elsevierStyleInf">2</span> response test were obtained after applying 5<span class="elsevierStyleHsp" style=""></span>min of pressure support ventilation with a pressure of 7<span class="elsevierStyleHsp" style=""></span>cm H<span class="elsevierStyleInf">2</span>O without PEEP&#44; and FiO<span class="elsevierStyleInf">2</span> was set at 1&#46;0 to prevent hypoxemia for patients&#8217; security and to avoid hypoxic stimuli&#46; Then&#44; respiratory rate&#44; airway occlusion pressure 0&#46;1<span class="elsevierStyleHsp" style=""></span>s after the beginning of inspiration &#40;P<span class="elsevierStyleInf">0&#46;1</span>&#41;&#44; and minute volume &#40;V<span class="elsevierStyleInf">E</span>&#41; were recorded from the ventilator&#44; and an arterial blood sample was withdrawn&#46; Thereafter&#44; we initiated the CO<span class="elsevierStyleInf">2</span> response test by increasing dead space maintaining the same ventilatory support&#44; and when the exhaled CO<span class="elsevierStyleInf">2</span> &#40;measured through capnography&#41; had increased by above 10<span class="elsevierStyleHsp" style=""></span>mm Hg&#44; we measured again the respiratory rate&#44; P<span class="elsevierStyleInf">0&#46;1</span> and V<span class="elsevierStyleInf">E</span>&#44; and withdrew another arterial blood sample&#46; Once the CO<span class="elsevierStyleInf">2</span> response test was finished the added dead space was removed and the patient was returned to his original assisted ventilation mode&#46;</p><p id="par0060" class="elsevierStylePara elsevierViewall">We studied the following derived indexes of CO<span class="elsevierStyleInf">2</span> response test&#58; the hypercapnic ventilatory response &#40;&#916;V<span class="elsevierStyleInf">E</span>&#47;&#916;PaCO<span class="elsevierStyleInf">2</span>&#41;&#44; defined as the ratio of the change in V<span class="elsevierStyleInf">E</span> &#40;&#916;V<span class="elsevierStyleInf">E</span>&#41; to the change in PaCO<span class="elsevierStyleInf">2</span> &#40;&#916;PaCO<span class="elsevierStyleInf">2</span>&#41; and the hypercapnic drive response &#40;&#916;P<span class="elsevierStyleInf">0&#46;1</span>&#47;&#916;PaCO<span class="elsevierStyleInf">2</span>&#41;&#44; defined as the ratio of the change in P<span class="elsevierStyleInf">0&#46;1</span> &#40;&#916;P<span class="elsevierStyleInf">0&#46;1</span>&#41; to &#916;PaCO<span class="elsevierStyleInf">2</span>&#46; The changes in V<span class="elsevierStyleInf">E</span>&#44; P<span class="elsevierStyleInf">0&#46;1</span>&#44; and PaCO<span class="elsevierStyleInf">2</span> were calculated as the difference between the value at the end of the CO<span class="elsevierStyleInf">2</span> response test and the baseline value&#46; P<span class="elsevierStyleInf">0&#46;1</span> was measured by means of the built-in system of the Dr&#228;ger ventilator &#40;Evita 2 Dura or Evita 4&#44; Dr&#228;ger&#44;&#160;L&#252;beck&#44; Germany&#41;&#44;<a class="elsevierStyleCrossRefs" href="#bib0090"><span class="elsevierStyleSup">18&#44;19</span></a> and P<span class="elsevierStyleInf">0&#46;1</span> was calculated as the mean of 5 measurements at each point of the study&#46; Arterial blood gases were measured with a blood gas analyzer &#40;IL-1650&#44; Instrument Laboratory&#44; Izasa&#44; Spain&#41;&#46;</p></span></span><span id="sec0040" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0140">Data collection and definitions</span><p id="par0065" class="elsevierStylePara elsevierViewall">We recorded the following clinical variables&#58; gender&#44; age&#44; height&#44; weight&#44; the Simplified Acute Physiological Score &#40;SAPS&#41; II&#44; <span class="elsevierStyleBold">length</span> of mechanical ventilation before the study day&#44; ICU and in-hospital length of stay&#44; and in-hospital mortality&#46;</p><p id="par0070" class="elsevierStylePara elsevierViewall">We considered the study day as the day that the CO<span class="elsevierStyleInf">2</span> response test was performed&#46; <span class="elsevierStyleBold">Length</span> of mechanical ventilation before the study day was defined as the number of days between the beginning of mechanical ventilation and the day the CO<span class="elsevierStyleInf">2</span> response test was performed&#46; Patients were followed-up until discharge from our two hospitals&#46;</p></span></span><span id="sec0045" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0145">Statistical analysis</span><p id="par0075" class="elsevierStylePara elsevierViewall">Categorical data are expressed as number and percentages&#46; Continuous variables are expressed as mean<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>standard deviation or as median and interquartile ranges &#40;IQR&#41;&#46; Differences between groups were compared with <span class="elsevierStyleItalic">t</span> test and chi-square test&#46; Non-COPD and COPD patients were grouped into tertiles according to the baseline level of plasma bicarbonate concentration&#46; Trend analysis among the tertiles of plasma bicarbonate concentration and changes of pH by changes of PaCO<span class="elsevierStyleInf">2</span>&#44; minute volume&#44; CO<span class="elsevierStyleInf">2</span> response&#44; tidal volume and respiratory rate&#44; were conducted with Jonckheere&#8211;Terpstra test&#46; Statistical analysis was performed with specific statistics software &#40;SPSS 19&#46;0&#44; SPSS&#44; Chicago&#44; IL&#41;&#46;</p></span><span id="sec0050" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0150">Results</span><p id="par0080" class="elsevierStylePara elsevierViewall">One hundred and sixty-eight patients were studied&#44; 120 patients in the non-COPD group and 48 in the COPD group&#46; The COPD group had a mean FEV1&#47;FVC ratio of 54<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>12&#37; and of the FEV1 of 37<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>16&#37;&#46; Compared with non-COPD patients&#44; COPD patients were mostly men&#44; with higher body mass index and lower severity disease &#40;<a class="elsevierStyleCrossRef" href="#tbl0005">Table 1</a>&#41;&#46; The main diagnoses of non-COPD patients were pneumonia and non-pulmonary sepsis &#40;<a class="elsevierStyleCrossRef" href="#tbl0005">Table 1</a>&#41;&#46; Non-COPD patients had longer duration of ventilation before the study day&#44; and longer ICU and in-hospital length of stay &#40;<a class="elsevierStyleCrossRef" href="#tbl0005">Table 1</a>&#41;&#46;</p><elsevierMultimedia ident="tbl0005"></elsevierMultimedia><p id="par0085" class="elsevierStylePara elsevierViewall">Between non-COPD and COPD groups there was no difference in the added dead space used to increase the PaCO<span class="elsevierStyleInf">2</span>&#46; Mean values were 414<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>70<span class="elsevierStyleHsp" style=""></span>mL and 392<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>68<span class="elsevierStyleHsp" style=""></span>mL respectively &#40;<span class="elsevierStyleItalic">p</span><span class="elsevierStyleHsp" style=""></span>&#61;<span class="elsevierStyleHsp" style=""></span>0&#46;08&#41;&#46; The baseline values of CO<span class="elsevierStyleInf">2</span> response test&#44; with pressure support ventilation of 7<span class="elsevierStyleHsp" style=""></span>cm H<span class="elsevierStyleInf">2</span>O and FiO<span class="elsevierStyleInf">2</span> of 1&#46;0 showed a higher plasma bicarbonate concentration and PaCO<span class="elsevierStyleInf">2</span> and lower minute volume&#44; respiratory rate and pH in COPD group compared with the non-COPD group &#40;<a class="elsevierStyleCrossRef" href="#tbl0010">Table 2</a>&#41;&#46; No differences were found in mean PaO<span class="elsevierStyleInf">2</span> and baseline P<span class="elsevierStyleInf">0&#46;1</span> values between groups &#40;<a class="elsevierStyleCrossRef" href="#tbl0010">Table 2</a>&#41;&#46; The ventilatory and central CO<span class="elsevierStyleInf">2</span> response was lower in COPD patients than in non-COPD&#46; No differences were found in respiratory muscle strength assessed by P<span class="elsevierStyleInf">Imax</span> and P<span class="elsevierStyleInf">Emax</span> between groups &#40;<a class="elsevierStyleCrossRef" href="#tbl0010">Table 2</a>&#41;&#46;</p><elsevierMultimedia ident="tbl0010"></elsevierMultimedia><p id="par0090" class="elsevierStylePara elsevierViewall">The tertile ranges of plasma bicarbonate concentration were 17&#46;1 to 24&#46;1&#44; 24&#46;1 to 26&#46;6 and 26&#46;6 to 37&#46;5<span class="elsevierStyleHsp" style=""></span>mmol&#47;L for non-COPD patients&#44; and 19&#46;7 to 30&#46;9&#44; 30&#46;9 to 35&#46;5 and 35&#46;5 to 43&#46;7<span class="elsevierStyleHsp" style=""></span>mmol&#47;L for COPD patients&#46; <span class="elsevierStyleBold">We found a significant inverse linear relationship between plasma bicarbonate concentration grouped in tertiles&#44; in non-COPD and COPD groups of patients&#44; and baseline minute volume &#40;</span><span class="elsevierStyleItalic"><span class="elsevierStyleBold">p</span></span><span class="elsevierStyleHsp" style=""></span>&#60;<span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleBold">0&#46;001&#41;</span> &#40;<a class="elsevierStyleCrossRef" href="#fig0005">Fig&#46; 1</a>&#41;&#46; The same inverse linear relationship in both groups of patients were found between the tertiles of plasma bicarbonate concentration and pH change per mm Hg of PaCO<span class="elsevierStyleInf">2</span><span class="elsevierStyleBold">induced by CO</span><span class="elsevierStyleInf"><span class="elsevierStyleBold">2</span></span><span class="elsevierStyleBold">response test</span> &#40;<span class="elsevierStyleItalic">p</span><span class="elsevierStyleHsp" style=""></span>&#60;<span class="elsevierStyleHsp" style=""></span>0&#46;001&#41; &#40;<a class="elsevierStyleCrossRef" href="#fig0010">Fig&#46; 2</a>&#41;&#44; <span class="elsevierStyleBold">and between the tertiles of plasma bicarbonate concentration and</span> hypercapnic ventilatory response &#40;<span class="elsevierStyleItalic">p</span><span class="elsevierStyleHsp" style=""></span>&#60;<span class="elsevierStyleHsp" style=""></span>0&#46;001&#41; and hypercapnic drive response &#40;<span class="elsevierStyleItalic">p</span><span class="elsevierStyleHsp" style=""></span>&#60;<span class="elsevierStyleHsp" style=""></span>0&#46;001&#41; &#40;<a class="elsevierStyleCrossRef" href="#fig0015">Fig&#46; 3</a>&#41;&#46;</p><elsevierMultimedia ident="fig0005"></elsevierMultimedia><elsevierMultimedia ident="fig0010"></elsevierMultimedia><elsevierMultimedia ident="fig0015"></elsevierMultimedia><p id="par0095" class="elsevierStylePara elsevierViewall">When plotted minute volume and P<span class="elsevierStyleInf">0&#46;1</span> against PaCO<span class="elsevierStyleInf">2</span>&#44; in non-COPD and COPD patients grouped by tertiles of plasma bicarbonate concentration&#44; the slope of the CO<span class="elsevierStyleInf">2</span> response flattened with high levels of plasma bicarbonate concentration &#40;<a class="elsevierStyleCrossRef" href="#fig0020">Fig&#46; 4</a>&#41;&#46; Of note&#44; baseline values of minute volume decreased with the increased level of plasma bicarbonate&#44; without changes in P<span class="elsevierStyleInf">0&#46;1</span>&#46; Minute volume decreases through decrease in tidal volume &#40;<span class="elsevierStyleItalic">p</span><span class="elsevierStyleHsp" style=""></span>&#61;<span class="elsevierStyleHsp" style=""></span>0&#46;003&#41; and respiratory frequency &#40;<span class="elsevierStyleItalic">P</span><span class="elsevierStyleHsp" style=""></span>&#60;<span class="elsevierStyleHsp" style=""></span>0&#46;001&#41; &#40;<a class="elsevierStyleCrossRef" href="#fig0025">Fig&#46; 5</a>&#41;&#46;</p><elsevierMultimedia ident="fig0020"></elsevierMultimedia><elsevierMultimedia ident="fig0025"></elsevierMultimedia></span><span id="sec0055" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0155">Discussion</span><p id="par0100" class="elsevierStylePara elsevierViewall">In this study we found an inverse relationship between the plasma bicarbonate concentration and the variation in pH for a given change in PaCO<span class="elsevierStyleInf">2</span>&#46; Indeed&#44; the most interesting finding was that the response to CO<span class="elsevierStyleInf">2</span> also inversely depends on the level of plasma bicarbonate concentration&#44; both in non-COPD and COPD patients&#44; during the weaning of mechanical ventilation&#46;</p><p id="par0105" class="elsevierStylePara elsevierViewall">These results are in agreement with previous studies in healthy subjects<a class="elsevierStyleCrossRefs" href="#bib0015"><span class="elsevierStyleSup">3&#44;4</span></a> and chronic hypercapnia secondary to kyphoscoliosis or skeletal muscle disease&#46;<a class="elsevierStyleCrossRefs" href="#bib0025"><span class="elsevierStyleSup">5&#44;6</span></a> In these studies the variations in plasma bicarbonate concentration were induced by oral administration of sodium bicarbonate and ethacrynic acid&#44; or ammonium chloride&#46; Our results are also in accordance with a previous study with obesity-hypoventilation syndrome patients during the weaning of mechanical ventilation&#46;<a class="elsevierStyleCrossRef" href="#bib0060"><span class="elsevierStyleSup">12</span></a> In that study we found the same inverse relationship between plasma bicarbonate concentration and CO<span class="elsevierStyleInf">2</span> response&#46; We also found that lowering plasma bicarbonate concentration by acetazolamide administration increased the CO<span class="elsevierStyleInf">2</span> response in a small subset of patients&#46;<a class="elsevierStyleCrossRef" href="#bib0060"><span class="elsevierStyleSup">12</span></a></p><p id="par0110" class="elsevierStylePara elsevierViewall">One possible explanation for several previous studies that did not find the relationship between the plasma bicarbonate concentration and CO<span class="elsevierStyleInf">2</span> response was that the changes in the bicarbonate concentrations were small and in some cases only toward acidosis&#46;<a class="elsevierStyleCrossRefs" href="#bib0035"><span class="elsevierStyleSup">7&#8211;11</span></a> Changes in the slope of the CO<span class="elsevierStyleInf">2</span> response are more evident when the patients reach high levels of plasma bicarbonate concentration&#44; as occurred in our study&#46;</p><p id="par0115" class="elsevierStylePara elsevierViewall">The ventilatory adaptation to an increase of plasma bicarbonate concentration is primarily achieved by decrease of tidal volume in subjects without lung disease&#44;<a class="elsevierStyleCrossRef" href="#bib0030"><span class="elsevierStyleSup">6</span></a> while we found a decrease in both tidal volume and respiratory rate&#46; This discordance may be related with the fact that they were studied with a pressure support of 7<span class="elsevierStyleHsp" style=""></span>cm H<span class="elsevierStyleInf">2</span>O&#46; Indeed&#44; Brochard et al&#46;<a class="elsevierStyleCrossRef" href="#bib0100"><span class="elsevierStyleSup">20</span></a> found that the ventilation with a pressure support of 10<span class="elsevierStyleHsp" style=""></span>cm H<span class="elsevierStyleInf">2</span>O during weaning of mechanical ventilation resulted in significant improvements in tidal volume with a decreased respiratory rate compared to spontaneous ventilation&#46;</p><p id="par0120" class="elsevierStylePara elsevierViewall">The clinical significance of this relationship between the level of plasma bicarbonate concentration and baseline minute volume and CO<span class="elsevierStyleInf">2</span> response relies on the fact that modifying the plasma bicarbonate concentration we can change the baseline minute volume&#44; the CO<span class="elsevierStyleInf">2</span> response&#44; and the work of breathing&#46; Thus&#44; in patients with COPD we could increase the minute volume and the CO<span class="elsevierStyleInf">2</span> response by reducing the plasma bicarbonate concentration&#46; Reducing elevated levels of plasma bicarbonate concentration is simple with the administration of acetazolamide&#44; as observed in our study of patients with obesity-hypoventilation syndrome&#46;<a class="elsevierStyleCrossRef" href="#bib0060"><span class="elsevierStyleSup">12</span></a> Ongoing clinical trials evaluating the use of acetazolamide to facilitate the weaning of mechanical ventilation will address this issue&#46; However&#44; one must bear in mind several issues when considering this potential treatment&#46; First&#44; when reducing elevated plasma bicarbonate concentration there is an inherent risk of increasing the work of breathing in excess&#46; Second&#44; in non-COPD patients ventilated with high minute volume and with difficulty of weaning of mechanical ventilation&#44; increasing the plasma bicarbonate concentration can reduce the minute volume and therefore the work of breathing&#46;</p><p id="par0125" class="elsevierStylePara elsevierViewall">Along with the plasma bicarbonate concentration&#44; the CO<span class="elsevierStyleInf">2</span> response depends on other factors such as the family&#44;<a class="elsevierStyleCrossRef" href="#bib0105"><span class="elsevierStyleSup">21</span></a> age&#44;<a class="elsevierStyleCrossRef" href="#bib0110"><span class="elsevierStyleSup">22</span></a> and circadian rhythm&#46;<a class="elsevierStyleCrossRef" href="#bib0115"><span class="elsevierStyleSup">23</span></a> In this regard&#44; we note that approximately 15&#37; of healthy subjects have decreased response to CO<span class="elsevierStyleInf">2</span>&#46; These individuals are likely to develop CO<span class="elsevierStyleInf">2</span> retention when additional respiratory problems arise&#44; such as obesity&#44; obstructive lung disease or status asthmaticus&#46;<a class="elsevierStyleCrossRefs" href="#bib0105"><span class="elsevierStyleSup">21&#44;24&#44;25</span></a> The reduced CO<span class="elsevierStyleInf">2</span> response in COPD patients cannot be attributed to hyperoxia&#46; In these patients&#44; the increase in the PaCO<span class="elsevierStyleInf">2</span> by hyperoxia is due to changes in the ventilation-perfusion distribution<a class="elsevierStyleCrossRefs" href="#bib0130"><span class="elsevierStyleSup">26&#44;27</span></a> and to the increase in dead space by the Haldane effect on PaCO<span class="elsevierStyleInf">2</span>&#46;<a class="elsevierStyleCrossRef" href="#bib0140"><span class="elsevierStyleSup">28</span></a><span class="elsevierStyleBold">Likewise&#44; the high PaO</span><span class="elsevierStyleInf"><span class="elsevierStyleBold">2</span></span><span class="elsevierStyleBold">observed in our patients may be explained by the FiO</span><span class="elsevierStyleInf"><span class="elsevierStyleBold">2</span></span><span class="elsevierStyleBold">of 1 used in the study to correct hypoxemia in all lung units regardless of their ventilation-perfusion ratio except with a pure shunt&#46;</span></p><p id="par0130" class="elsevierStylePara elsevierViewall">The main limitation of this study was the difficulty to interpret the results of the CO<span class="elsevierStyleInf">2</span> response tests due to the wide range of normal values in healthy subjects&#46;<a class="elsevierStyleCrossRefs" href="#bib0145"><span class="elsevierStyleSup">29&#44;30</span></a> In addition&#44; the coefficients of variation are also wide&#44; from 17&#46;9&#37; for the ventilatory response &#40;ranged from 8&#46;3 to 26&#46;3&#37;&#41;<a class="elsevierStyleCrossRef" href="#bib0155"><span class="elsevierStyleSup">31</span></a> and about 60&#37; for the P<span class="elsevierStyleInf">0&#46;1</span> during CO<span class="elsevierStyleInf">2</span> rebreathing trials&#46;<a class="elsevierStyleCrossRef" href="#bib0160"><span class="elsevierStyleSup">32</span></a> Other limitations of our study were the way in which we measured CO<span class="elsevierStyleInf">2</span> response with the ventilator&#44; instead of with the conventional method&#46;<a class="elsevierStyleCrossRef" href="#bib0165"><span class="elsevierStyleSup">33</span></a> The Evita ventilator tends to overestimate high P<span class="elsevierStyleInf">0&#46;1</span> values and to underestimate low P<span class="elsevierStyleInf">0&#46;1</span> values&#46;<a class="elsevierStyleCrossRef" href="#bib0095"><span class="elsevierStyleSup">19</span></a> Another possible limitation is air trapping due to the high minute volume that occurs with hypercapnic stimulation or by effect of bronchoconstriction in patients with COPD&#46; However&#44; Conti et al&#46;<a class="elsevierStyleCrossRef" href="#bib0170"><span class="elsevierStyleSup">34</span></a> found that reliable measurement of P<span class="elsevierStyleInf">0&#46;1</span> can be obtained during pressure-support ventilation in patients with variable levels of intrinsic PEEP&#46;</p><p id="par0135" class="elsevierStylePara elsevierViewall">In conclusion&#44; we observed an inverse relationship between the plasma bicarbonate concentration and the variation in hydrogen ion concentration for a given change in PaCO<span class="elsevierStyleInf">2</span>&#44; and we found that elevated levels of plasma bicarbonate reduced the CO<span class="elsevierStyleInf">2</span> response both in COPD and non-COPD critically ill patients during weaning of mechanical ventilation&#46;</p></span><span id="sec0060" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0160">Conflict of interest</span><p id="par0140" class="elsevierStylePara elsevierViewall">All authors declare that they have no conflict of interest&#46;</p></span></span>"
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            1 => "Objetivo"
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            3 => "&#193;mbito"
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              "titulo" => "Measurements and procedures"
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                  "titulo" => "Maximal inspiratory and expiratory pressure"
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                  "titulo" => "CO response test"
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              "titulo" => "Data collection and definitions"
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    "fechaRecibido" => "2013-07-30"
    "fechaAceptado" => "2013-10-22"
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          "clase" => "keyword"
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            0 => "Hypercapnia"
            1 => "Bicarbonate"
            2 => "Chronic obstructive pulmonary disease"
            3 => "Mechanical ventilation"
            4 => "Respiratory center"
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            0 => "Hipercapnia"
            1 => "Bicarbonato"
            2 => "Enfermedad pulmonar obstructiva cr&#243;nica"
            3 => "Ventilaci&#243;n mec&#225;nica"
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        "titulo" => "Abstract"
        "resumen" => "<span class="elsevierStyleSectionTitle" id="sect0010">Objective</span><p id="spar0005" class="elsevierStyleSimplePara elsevierViewall">There is controversy about the effects of high plasma bicarbonate concentration &#40;&#91;HCO3<span class="elsevierStyleSup">&#8722;</span>&#93;&#41; and the CO<span class="elsevierStyleInf">2</span> response test&#46; We analyzed the relationship between &#91;HCO3<span class="elsevierStyleSup">&#8722;</span>&#93; and the variation in hydrogen ion concentration &#40;pH&#41; for a given change in PaCO<span class="elsevierStyleInf">2</span>&#44; and its effects upon CO<span class="elsevierStyleInf">2</span> response&#46;</p> <span class="elsevierStyleSectionTitle" id="sect0015">Design</span><p id="spar0010" class="elsevierStyleSimplePara elsevierViewall">A retrospective study was carried out&#46;</p> <span class="elsevierStyleSectionTitle" id="sect0020">Setting</span><p id="spar0015" class="elsevierStyleSimplePara elsevierViewall">Two intensive care units&#46;</p> <span class="elsevierStyleSectionTitle" id="sect0025">Patients</span><p id="spar0020" class="elsevierStyleSimplePara elsevierViewall">Subjects with and without chronic obstructive pulmonary disease &#40;COPD&#41;&#44; at the beginning of weaning from mechanical ventilation&#46;</p> <span class="elsevierStyleSectionTitle" id="sect0030">Interventions</span><p id="spar0025" class="elsevierStyleSimplePara elsevierViewall">The CO<span class="elsevierStyleInf">2</span> response was evaluated by the re-inhalation of expired air method&#44; measuring the hypercapnic ventilatory response &#40;&#916;V<span class="elsevierStyleInf">E</span>&#47;&#916;PaCO<span class="elsevierStyleInf">2</span>&#41; and hypercapnic drive response &#40;&#916;P<span class="elsevierStyleInf">01</span>&#47;&#916;PaCO<span class="elsevierStyleInf">2</span>&#41;&#44; where V<span class="elsevierStyleInf">E</span> is minute volume and P<span class="elsevierStyleInf">0&#46;1</span> is airway occlusion pressure 0&#46;1<span class="elsevierStyleHsp" style=""></span>s after the initiation of inspiration&#46;</p> <span class="elsevierStyleSectionTitle" id="sect0035">Main outcome measures</span><p id="spar0030" class="elsevierStyleSimplePara elsevierViewall">&#91;HCO3<span class="elsevierStyleSup">&#8722;</span>&#93; and CO<span class="elsevierStyleInf">2</span> response&#46;</p> <span class="elsevierStyleSectionTitle" id="sect0040">Results</span><p id="spar0035" class="elsevierStyleSimplePara elsevierViewall">A total of 120 patients in the non-COPD group and 48 in the COPD group were studied&#46; COPD patients had higher mean &#91;HCO3<span class="elsevierStyleSup">&#8722;</span>&#93; than non-COPD patients &#40;33&#46;2<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>5&#46;4 vs&#46; 25&#46;7<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>3&#46;7<span class="elsevierStyleHsp" style=""></span>mmol&#47;l&#44; <span class="elsevierStyleItalic">p</span><span class="elsevierStyleHsp" style=""></span>&#60;<span class="elsevierStyleHsp" style=""></span>0&#46;001&#41;&#46; In both non-COPD and COPD patients we observed a significant inverse linear relationship between &#91;HCO3<span class="elsevierStyleSup">&#8722;</span>&#93; and pH change per mmHg of PaCO<span class="elsevierStyleInf">2</span> &#40;<span class="elsevierStyleItalic">p</span><span class="elsevierStyleHsp" style=""></span>&#60;<span class="elsevierStyleHsp" style=""></span>0&#46;001&#41;&#44; &#916;V<span class="elsevierStyleInf">E</span>&#47;&#916;PaCO<span class="elsevierStyleInf">2</span> &#40;<span class="elsevierStyleItalic">p</span><span class="elsevierStyleHsp" style=""></span>&#60;<span class="elsevierStyleHsp" style=""></span>0&#46;001&#41; and &#916;P<span class="elsevierStyleInf">0&#46;1</span>&#47;&#916;PaCO<span class="elsevierStyleInf">2</span> &#40;<span class="elsevierStyleItalic">p</span><span class="elsevierStyleHsp" style=""></span>&#60;<span class="elsevierStyleHsp" style=""></span>0&#46;001&#41;&#46;</p> <span class="elsevierStyleSectionTitle" id="sect0045">Conclusions</span><p id="spar0040" class="elsevierStyleSimplePara elsevierViewall">There is an inverse linear relationship between &#91;HCO3<span class="elsevierStyleSup">&#8722;</span>&#93; and the variation of pH for a given change in PaCO<span class="elsevierStyleInf">2</span> and the CO<span class="elsevierStyleInf">2</span> response&#46;</p>"
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      "es" => array:2 [
        "titulo" => "Resumen"
        "resumen" => "<span class="elsevierStyleSectionTitle" id="sect0055">Objetivo</span><p id="spar0045" class="elsevierStyleSimplePara elsevierViewall">Existe controversia en si las diferencias en la concentraci&#243;n plasm&#225;tica de bicarbonato &#40;CO3H<span class="elsevierStyleSup">&#8722;</span>&#41; modifican la respuesta al incremento de CO<span class="elsevierStyleInf">2</span>&#46; Hemos analizado la relaci&#243;n entre la CO3H<span class="elsevierStyleSup">&#8722;</span> y la variaci&#243;n en la concentraci&#243;n de iones de hidr&#243;geno &#40;pH&#41; por un incremento agudo de la PaCO<span class="elsevierStyleInf">2</span> y entre la CO3H<span class="elsevierStyleSup">&#8722;</span> y la respuesta del sistema respiratorio al incremento de CO<span class="elsevierStyleInf">2</span>&#46;</p> <span class="elsevierStyleSectionTitle" id="sect0060">Dise&#241;o</span><p id="spar0050" class="elsevierStyleSimplePara elsevierViewall">Estudio retrospectivo&#46;</p> <span class="elsevierStyleSectionTitle" id="sect0065">&#193;mbito</span><p id="spar0055" class="elsevierStyleSimplePara elsevierViewall">Dos unidades de cuidados intensivos&#46;</p> <span class="elsevierStyleSectionTitle" id="sect0070">Pacientes</span><p id="spar0060" class="elsevierStyleSimplePara elsevierViewall">Pacientes con y sin enfermedad pulmonar obstructiva cr&#243;nica &#40;EPOC&#41; en el inicio de la desconexi&#243;n de ventilaci&#243;n mec&#225;nica&#46;</p> <span class="elsevierStyleSectionTitle" id="sect0075">Intervenciones</span><p id="spar0065" class="elsevierStyleSimplePara elsevierViewall">La respuesta del sistema respiratorio al incremento de CO<span class="elsevierStyleInf">2</span> fue evaluada por el m&#233;todo de reinhalaci&#243;n del aire espirado&#44; midiendo la respuesta ventilatoria a la hipercapnia &#40;&#916;V<span class="elsevierStyleInf">E</span>&#47;&#916;PaCO<span class="elsevierStyleInf">2</span>&#41; y la respuesta del centro respiratorio a la hipercapnia &#40;&#916;P<span class="elsevierStyleInf">0&#44;1</span>&#47;&#916;PaCO<span class="elsevierStyleInf">2</span>&#41;&#44; donde V<span class="elsevierStyleInf">E</span> es el volumen minuto y P<span class="elsevierStyleInf">0&#44;1</span> es la presi&#243;n de oclusi&#243;n de la v&#237;a a&#233;rea a 0&#44;1 s del inicio de la inspiraci&#243;n&#46;</p> <span class="elsevierStyleSectionTitle" id="sect0080">Variables de inter&#233;s principales</span><p id="spar0070" class="elsevierStyleSimplePara elsevierViewall">CO3H<span class="elsevierStyleSup">&#8722;</span> y respuesta al CO<span class="elsevierStyleInf">2</span>&#46;</p> <span class="elsevierStyleSectionTitle" id="sect0085">Resultados</span><p id="spar0075" class="elsevierStyleSimplePara elsevierViewall">Fueron estudiados 120 pacientes sin EPOC y 48 con EPOC&#46; Las CO3H<span class="elsevierStyleSup">&#8722;</span> medias en los pacientes sin y con EPOC fueron de 25&#44;7<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>3&#44;7 y 33&#44;2<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>5&#44;4 mmol&#47;L&#44; respectivamente &#40;p<span class="elsevierStyleHsp" style=""></span>&#60;<span class="elsevierStyleHsp" style=""></span>0&#44;001&#41;&#46; Hallamos&#44; en ambos grupos de pacientes&#44; una relaci&#243;n linear inversa entre la CO3H<span class="elsevierStyleSup">&#8722;</span> y el cambio de pH por mmHg de PaCO<span class="elsevierStyleInf">2</span> &#40;p<span class="elsevierStyleHsp" style=""></span>&#60;<span class="elsevierStyleHsp" style=""></span>0&#44;001&#41;&#44; el &#916;V<span class="elsevierStyleInf">E</span>&#47;&#916;PaCO<span class="elsevierStyleInf">2</span> &#40;p<span class="elsevierStyleHsp" style=""></span>&#60;<span class="elsevierStyleHsp" style=""></span>0&#44;001&#41; y el &#916;P<span class="elsevierStyleInf">0&#44;1</span>&#47;&#916;PaCO<span class="elsevierStyleInf">2</span> &#40;p<span class="elsevierStyleHsp" style=""></span>&#60;<span class="elsevierStyleHsp" style=""></span>0&#44;001&#41;&#46;</p> <span class="elsevierStyleSectionTitle" id="sect0090">Conclusiones</span><p id="spar0080" class="elsevierStyleSimplePara elsevierViewall">Hay una relaci&#243;n linear inversa entre la CO3H<span class="elsevierStyleSup">&#8722;</span> y la variaci&#243;n en el pH por un incremento agudo de la PaCO<span class="elsevierStyleInf">2</span> y entre la CO3H<span class="elsevierStyleSup">&#8722;</span> y la respuesta al CO<span class="elsevierStyleInf">2</span>&#46;</p>"
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          "en" => "<p id="spar0085" class="elsevierStyleSimplePara elsevierViewall">Relationship between plasma bicarbonate concentration grouped in tertiles and baseline minute volume expressed by body weight in mL&#47;min&#47;kg&#44; in non-COPD &#40;white circles&#41; and COPD patients &#40;black circles&#41;&#46; Dashed lines show the linear relationship among groups &#40;<span class="elsevierStyleItalic">p</span><span class="elsevierStyleHsp" style=""></span>&#60;<span class="elsevierStyleHsp" style=""></span>0&#46;001 for each variable&#41;&#46; Values are expressed as mean and standard error&#46;</p>"
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        "mostrarDisplay" => false
        "figura" => array:1 [
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          "en" => "<p id="spar0090" class="elsevierStyleSimplePara elsevierViewall">Relationship between plasma bicarbonate concentration grouped in tertiles and pH change per mm Hg of PaCO<span class="elsevierStyleInf">2</span>&#44; in non-COPD &#40;white circles&#41; and COPD patients &#40;black circles&#41;&#46; Dashed lines show the linear relationship among groups &#40;<span class="elsevierStyleItalic">p</span><span class="elsevierStyleHsp" style=""></span>&#60;<span class="elsevierStyleHsp" style=""></span>0&#46;001&#41;&#46; Values are expressed as mean and standard error&#46;</p>"
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      2 => array:7 [
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        "etiqueta" => "Figure 3"
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        "mostrarFloat" => true
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        "figura" => array:1 [
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          "en" => "<p id="spar0095" class="elsevierStyleSimplePara elsevierViewall">Relationship between plasma bicarbonate concentration grouped in tertiles and hypercapnic ventilatory response &#40;&#916;V<span class="elsevierStyleInf">E</span>&#47;&#916;PaCO<span class="elsevierStyleInf">2</span>&#41; &#40;top&#41;&#44; and hypercapnic drive response &#40;&#916;P<span class="elsevierStyleInf">0&#46;1</span>&#47;&#916;PaCO<span class="elsevierStyleInf">2</span>&#41; &#40;bottom&#41;&#44; in non-COPD &#40;white circles&#41; and COPD patients &#40;black circles&#41;&#46; Dashed lines show the linear relationship among groups &#40;<span class="elsevierStyleItalic">p</span><span class="elsevierStyleHsp" style=""></span>&#60;<span class="elsevierStyleHsp" style=""></span>0&#46;001 for each variable&#41;&#46; Values are expressed as mean and standard error&#46;</p>"
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      3 => array:7 [
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        "etiqueta" => "Figure 4"
        "tipo" => "MULTIMEDIAFIGURA"
        "mostrarFloat" => true
        "mostrarDisplay" => false
        "figura" => array:1 [
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          "en" => "<p id="spar0100" class="elsevierStyleSimplePara elsevierViewall">Baseline and response to CO<span class="elsevierStyleInf">2</span> increase of minute volume &#40;V<span class="elsevierStyleInf">E</span>&#41; and occlusion pressure &#40;P<span class="elsevierStyleInf">0&#46;1</span>&#41;&#46; The patients were grouped according to tertiles of bicarbonate concentration&#44; in non-COPD &#40;white circles&#41; and COPD patients &#40;black circles&#41;&#46; Values are expressed as mean and standard error&#46;</p>"
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      4 => array:7 [
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        "mostrarFloat" => true
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        "figura" => array:1 [
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          "en" => "<p id="spar0105" class="elsevierStyleSimplePara elsevierViewall">Relationship between plasma bicarbonate concentration grouped in tertiles and tidal volume &#40;V<span class="elsevierStyleInf">T</span>&#41; in mL&#47;kg of body weight and respiratory rate in breath per minute &#40;bpm&#41;&#44; in non-COPD &#40;white circles&#41; and COPD patients &#40;black circles&#41;&#46; Dashed lines show the linear relationship among groups&#46; Values are expressed as mean and standard error&#46;</p>"
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                  \t\t\t\t">31&#46;9<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>8&#46;6&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t">0&#46;004&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t">36<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>11&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t">0&#46;02&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t">2 &#40;4&#46;2&#37;&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
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                  \t\t\t\t">&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t">37 &#40;30&#46;8&#37;&#41;&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">&#8211;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
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                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>Postoperative state&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">19 &#40;15&#46;8&#37;&#41;&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t</td><td class="td" title="\n
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                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>Exacerbated COPD&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t  " align="char" valign="\n
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                  \t\t\t\t">&#8211;&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>Length of ventilation before study day&#44; days<a class="elsevierStyleCrossRef" href="#tblfn0005"><span class="elsevierStyleSup">&#42;</span></a>&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>Length of weaning&#44; days<a class="elsevierStyleCrossRef" href="#tblfn0005"><span class="elsevierStyleSup">&#42;</span></a>&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t">1 &#40;0&#8211;7&#41;&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t\ttop\n
                  \t\t\t\t">&#60;0&#46;001&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>ICU LOS&#44; days<a class="elsevierStyleCrossRef" href="#tblfn0005"><span class="elsevierStyleSup">&#42;</span></a>&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t">22 &#40;13&#8211;40&#41;&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t\ttop\n
                  \t\t\t\t">7 &#40;5&#8211;14&#41;&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t\ttop\n
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                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>In-hospital LOS&#44; days<a class="elsevierStyleCrossRef" href="#tblfn0005"><span class="elsevierStyleSup">&#42;</span></a>&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t\ttable-entry\n
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                  \t\t\t\t\ttop\n
                  \t\t\t\t">46 &#40;29&#8211;75&#41;&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t">21 &#40;13&#8211;29&#41;&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>In-hospital mortality&#44; <span class="elsevierStyleItalic">n</span> &#40;&#37;&#41;&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t">32 &#40;26&#46;7&#41;&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t">9 &#40;18&#46;8&#41;&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t">0&#46;32&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t" style="border-bottom: 2px solid black">Non-COPD <span class="elsevierStyleItalic">n</span>&#58; 120&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>Baseline PaO<span class="elsevierStyleInf">2</span> at FiO<span class="elsevierStyleInf">2</span> of 1&#46;0&#44; mm Hg&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t">410<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>114&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>Baseline CO<span class="elsevierStyleInf">3</span>H mmol&#47;L&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t">33&#46;2<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>5&#46;4&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t">7&#46;42<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>0&#46;05&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t">7&#46;38<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>0&#46;05&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>Hypercapnia&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t">7&#46;31<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>0&#46;05&nbsp;\t\t\t\t\t\t\n
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                  \t\t\t\t">7&#46;29<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>0&#46;05&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">0&#46;02&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " colspan="4" align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleVsp" style="height:0.5px"></span></td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " colspan="4" align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleItalic">PaCO</span><span class="elsevierStyleInf"><span class="elsevierStyleItalic">2</span></span><span class="elsevierStyleItalic">&#44; mm Hg</span></td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>Baseline&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">39&#46;6<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>7&#46;4&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">56&#46;1<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>12&#46;3&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">&#60;0&#46;001&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>Hypercapnia&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">55&#46;6<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>10&#46;2&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">73&#46;2<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>15&#46;1&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">&#60;0&#46;001&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " colspan="4" align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleVsp" style="height:0.5px"></span></td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " colspan="4" align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleItalic">Respiratory rate&#44; bpm</span></td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>Baseline&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">28<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>7&#46;3&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">23<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>6&#46;0&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">&#60;0&#46;001&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>Hypercapnia&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">34<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>7&#46;4&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">28<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>7&#46;8&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">&#60;0&#46;001&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " colspan="4" align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleVsp" style="height:0.5px"></span></td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " colspan="4" align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleItalic">Minute ventilation&#44; L&#47;min</span></td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>Baseline&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">11&#46;2<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>3&#46;2&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">9&#46;0<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>2&#46;5&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">&#60;0&#46;001&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>Hypercapnia&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">18&#46;3<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>4&#46;9&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">13&#46;4<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>4&#46;1&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">&#60;0&#46;001&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " colspan="4" align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleVsp" style="height:0.5px"></span></td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " colspan="4" align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleItalic">P</span><span class="elsevierStyleInf"><span class="elsevierStyleItalic">0&#46;1</span></span><span class="elsevierStyleItalic">&#44; cm H</span><span class="elsevierStyleInf"><span class="elsevierStyleItalic">2</span></span><span class="elsevierStyleItalic">O</span></td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>Baseline&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">3&#46;2<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>1&#46;9&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">2&#46;9<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>1&#46;6&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">0&#46;32&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>Hypercapnia&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">9&#46;7<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>3&#46;9&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">7&#46;0<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>3&#46;1&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">&#60;0&#46;001&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>&#916;V<span class="elsevierStyleInf">E</span>&#47;&#916;PaCO<span class="elsevierStyleInf">2</span>&#44; L&#47;min&#47;mm Hg&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">0&#46;52<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>0&#46;37&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">0&#46;30<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>0&#46;20&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">&#60;0&#46;001&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>&#916;P<span class="elsevierStyleInf">0&#46;1</span>&#47;&#916;PaCO<span class="elsevierStyleInf">2</span>&#44; cm H<span class="elsevierStyleInf">2</span>O&#47;mm Hg&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">0&#46;44<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>0&#46;26&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">0&#46;27<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>0&#46;18&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">&#60;0&#46;001&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " colspan="4" align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleVsp" style="height:0.5px"></span></td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " colspan="4" align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleItalic">Respiratory muscle strength</span></td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>P<span class="elsevierStyleInf">Imax</span>&#44; cm H<span class="elsevierStyleInf">2</span>O&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">46<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>18&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">47<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>14&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">0&#46;80&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="left" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t"><span class="elsevierStyleHsp" style=""></span>P<span class="elsevierStyleInf">Emax</span>&#44; cm H<span class="elsevierStyleInf">2</span>O&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">26<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>13&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
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                  \t\t\t\t">27<span class="elsevierStyleHsp" style=""></span>&#177;<span class="elsevierStyleHsp" style=""></span>13&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="\n
                  \t\t\t\t\ttable-entry\n
                  \t\t\t\t  " align="char" valign="\n
                  \t\t\t\t\ttop\n
                  \t\t\t\t">0&#46;57&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr></tbody></table>
                  """
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                0 => "xTab491858.png"
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        "descripcion" => array:1 [
          "en" => "<p id="spar0120" class="elsevierStyleSimplePara elsevierViewall">CO<span class="elsevierStyleInf">2</span> response test &#40;baseline and hypercapnia values of arterial blood gases and ventilatory parameters&#41; and respiratory muscle strength &#40;P<span class="elsevierStyleInf">Emax</span> and P<span class="elsevierStyleInf">Imax</span> values&#41;&#46;</p>"
        ]
      ]
    ]
    "bibliografia" => array:2 [
      "titulo" => "References"
      "seccion" => array:1 [
        0 => array:2 [
          "identificador" => "bibs0005"
          "bibliografiaReferencia" => array:34 [
            0 => array:3 [
              "identificador" => "bib0005"
              "etiqueta" => "1"
              "referencia" => array:1 [
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                    0 => array:2 [
                      "titulo" => "Incidence of metabolic alkalemia in hospitalized patients"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:3 [
                            0 => "J&#46;E&#46; Hodgkin"
                            1 => "F&#46;F&#46; Soeprono"
                            2 => "D&#46;M&#46; Chan"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:7 [
                        "tituloSerie" => "Crit Care Med"
                        "fecha" => "1980"
                        "volumen" => "8"
                        "paginaInicial" => "725"
                        "paginaFinal" => "728"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/6778655"
                            "web" => "Medline"
                          ]
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                          "pii" => "S0140673600028440"
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                          "issn" => "01406736"
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              ]
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            1 => array:3 [
              "identificador" => "bib0010"
              "etiqueta" => "2"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Determinants of blood pH in health and disease"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:1 [
                            0 => "J&#46;A&#46; Kellum"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1186/cc644"
                      "Revista" => array:7 [
                        "tituloSerie" => "Crit Care"
                        "fecha" => "2000"
                        "volumen" => "4"
                        "paginaInicial" => "6"
                        "paginaFinal" => "14"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/11094491"
                            "web" => "Medline"
                          ]
                        ]
                        "itemHostRev" => array:3 [
                          "pii" => "S0735109705023417"
                          "estado" => "S300"
                          "issn" => "07351097"
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                    ]
                  ]
                ]
              ]
            ]
            2 => array:3 [
              "identificador" => "bib0015"
              "etiqueta" => "3"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Respiration in man during metabolic alkalosis"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:1 [
                            0 => "D&#46;J&#46; Stone"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:6 [
                        "tituloSerie" => "J Appl Physiol"
                        "fecha" => "1962"
                        "volumen" => "17"
                        "paginaInicial" => "33"
                        "paginaFinal" => "37"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/13917462"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            3 => array:3 [
              "identificador" => "bib0020"
              "etiqueta" => "4"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Compensatory hypoventilation in metabolic alkalosis"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:4 [
                            0 => "S&#46; Javaheri"
                            1 => "N&#46;S&#46; Shore"
                            2 => "B&#46; Rose"
                            3 => "H&#46; Kazemi"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:6 [
                        "tituloSerie" => "Chest"
                        "fecha" => "1982"
                        "volumen" => "81"
                        "paginaInicial" => "296"
                        "paginaFinal" => "301"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/6799256"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            4 => array:3 [
              "identificador" => "bib0025"
              "etiqueta" => "5"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Respiratory-renal adjustments in chronic hypercapnia in man&#46; Extracellular bicarbonate concentration and the regulation of ventilation"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:3 [
                            0 => "R&#46;M&#46; Goldring"
                            1 => "G&#46;M&#46; Turino"
                            2 => "H&#46;O&#46; Heinemann"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:6 [
                        "tituloSerie" => "Am J Med"
                        "fecha" => "1971"
                        "volumen" => "51"
                        "paginaInicial" => "772"
                        "paginaFinal" => "784"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/5129545"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            5 => array:3 [
              "identificador" => "bib0030"
              "etiqueta" => "6"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Bicarbonate and the regulation of ventilation"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:2 [
                            0 => "H&#46;O&#46; Heinemann"
                            1 => "R&#46;M&#46; Goldring"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:7 [
                        "tituloSerie" => "Am J Med"
                        "fecha" => "1974"
                        "volumen" => "57"
                        "paginaInicial" => "361"
                        "paginaFinal" => "370"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/4606269"
                            "web" => "Medline"
                          ]
                        ]
                        "itemHostRev" => array:3 [
                          "pii" => "S0735109706012630"
                          "estado" => "S300"
                          "issn" => "07351097"
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            6 => array:3 [
              "identificador" => "bib0035"
              "etiqueta" => "7"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "The effect of maintained ammonium chloride acidosis on the relation between pulmonary ventilation and alveolar oxygen and carbon dioxide in man"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:4 [
                            0 => "D&#46;J&#46; Cunningham"
                            1 => "D&#46;G&#46; Shaw"
                            2 => "S&#46; Lahiri"
                            3 => "B&#46;B&#46; Lloyd"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:6 [
                        "tituloSerie" => "Q J Exp Physiol Cogn Med Sci"
                        "fecha" => "1961"
                        "volumen" => "46"
                        "paginaInicial" => "323"
                        "paginaFinal" => "334"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/13882641"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            7 => array:3 [
              "identificador" => "bib0040"
              "etiqueta" => "8"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Respiratory control at high altitude suggesting active transport regulation of CSF pH"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:4 [
                            0 => "J&#46;W&#46; Severinghaus"
                            1 => "R&#46;A&#46; Mitchell"
                            2 => "B&#46;W&#46; Richardson"
                            3 => "M&#46;M&#46; Singer"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:6 [
                        "tituloSerie" => "J Appl Physiol"
                        "fecha" => "1963"
                        "volumen" => "18"
                        "paginaInicial" => "1155"
                        "paginaFinal" => "1166"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/14080735"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            8 => array:3 [
              "identificador" => "bib0045"
              "etiqueta" => "9"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Respiration and cerebrospinal fluid pH in metabolic acidosis and alkalosis"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:2 [
                            0 => "R&#46;A&#46; Mitchell"
                            1 => "M&#46;M&#46; Singer"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:6 [
                        "tituloSerie" => "J Appl Physiol"
                        "fecha" => "1965"
                        "volumen" => "20"
                        "paginaInicial" => "905"
                        "paginaFinal" => "911"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/5837617"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            9 => array:3 [
              "identificador" => "bib0050"
              "etiqueta" => "10"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Respiration and cerebral blood flow in metabolic acidosis and alkalosis in humans"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:3 [
                            0 => "V&#46; Fencl"
                            1 => "J&#46;R&#46; Vale"
                            2 => "J&#46;A&#46; Broch"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:6 [
                        "tituloSerie" => "J Appl Physiol"
                        "fecha" => "1969"
                        "volumen" => "27"
                        "paginaInicial" => "67"
                        "paginaFinal" => "76"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/5786972"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            10 => array:3 [
              "identificador" => "bib0055"
              "etiqueta" => "11"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Relationship of CSF pH&#44; O2&#44; and CO2 responses in metabolic acidosis and alkalosis in humans"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:3 [
                            0 => "G&#46;B&#46; Irsigler"
                            1 => "M&#46;J&#46; Stafford"
                            2 => "J&#46;W&#46; Severinghaus"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:6 [
                        "tituloSerie" => "J Appl Physiol"
                        "fecha" => "1980"
                        "volumen" => "48"
                        "paginaInicial" => "355"
                        "paginaFinal" => "361"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/6767670"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            11 => array:3 [
              "identificador" => "bib0060"
              "etiqueta" => "12"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Hypercapnic respiratory failure in obesity-hypoventilation syndrome&#58; CO&#40;2&#41; response and acetazolamide treatment effects"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:5 [
                            0 => "J&#46;M&#46; Raurich"
                            1 => "G&#46; Rialp"
                            2 => "J&#46; Ibanez"
                            3 => "J&#46;A&#46; Llompart-Pou"
                            4 => "I&#46; Ayestaran"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:6 [
                        "tituloSerie" => "Respir Care"
                        "fecha" => "2010"
                        "volumen" => "55"
                        "paginaInicial" => "1442"
                        "paginaFinal" => "1448"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/20979670"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            12 => array:3 [
              "identificador" => "bib0065"
              "etiqueta" => "13"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Hypercapnia test as a predictor of success in spontaneous breathing trials and extubation"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:6 [
                            0 => "J&#46;M&#46; Raurich"
                            1 => "G&#46; Rialp"
                            2 => "J&#46; Ibanez"
                            3 => "C&#46; Campillo"
                            4 => "I&#46; Ayestaran"
                            5 => "C&#46; Blanco"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:6 [
                        "tituloSerie" => "Respir Care"
                        "fecha" => "2008"
                        "volumen" => "53"
                        "paginaInicial" => "1012"
                        "paginaFinal" => "1018"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/18655738"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            13 => array:3 [
              "identificador" => "bib0070"
              "etiqueta" => "14"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Hypercapnia test and weaning outcome from mechanical ventilation in COPD patients"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:6 [
                            0 => "J&#46;M&#46; Raurich"
                            1 => "G&#46; Rialp"
                            2 => "J&#46; Ibanez"
                            3 => "I&#46; Ayestaran"
                            4 => "J&#46;A&#46; Llompart-Pou"
                            5 => "B&#46; Togores"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:6 [
                        "tituloSerie" => "Anaesth Intensive Care"
                        "fecha" => "2009"
                        "volumen" => "37"
                        "paginaInicial" => "726"
                        "paginaFinal" => "732"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/19775035"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            14 => array:3 [
              "identificador" => "bib0075"
              "etiqueta" => "15"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "CO2 response and duration of weaning from mechanical ventilation"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:5 [
                            0 => "J&#46;M&#46; Raurich"
                            1 => "G&#46; Rialp"
                            2 => "J&#46; Ibanez"
                            3 => "J&#46;A&#46; Llompart-Pou"
                            4 => "I&#46; Ayestaran"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.4187/respcare.01080"
                      "Revista" => array:6 [
                        "tituloSerie" => "Respir Care"
                        "fecha" => "2011"
                        "volumen" => "56"
                        "paginaInicial" => "1130"
                        "paginaFinal" => "1136"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/21496366"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            15 => array:3 [
              "identificador" => "bib0080"
              "etiqueta" => "16"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Estimation of inspiratory muscle strength in mechanically ventilated patients&#58; the measurement of maximal inspiratory pressure"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:3 [
                            0 => "J&#46;J&#46; Marini"
                            1 => "T&#46;C&#46; Smith"
                            2 => "V&#46; Lamb"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "J Crit Care"
                        "fecha" => "1986"
                        "volumen" => "1"
                        "paginaInicial" => "32"
                        "paginaFinal" => "38"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            16 => array:3 [
              "identificador" => "bib0085"
              "etiqueta" => "17"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Ventilatory responses to dead space and CO2 breathing under inspiratory resistive load"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:2 [
                            0 => "D&#46;A&#46; Sidney"
                            1 => "C&#46;S&#46; Poon"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:6 [
                        "tituloSerie" => "J Appl Physiol"
                        "fecha" => "1995"
                        "volumen" => "78"
                        "paginaInicial" => "555"
                        "paginaFinal" => "561"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/7759425"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            17 => array:3 [
              "identificador" => "bib0090"
              "etiqueta" => "18"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "A new method for P0&#46;1 measurement using standard respiratory equipment"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:6 [
                            0 => "R&#46; Kuhlen"
                            1 => "S&#46; Hausmann"
                            2 => "D&#46; Pappert"
                            3 => "K&#46; Slama"
                            4 => "R&#46; Rossaint"
                            5 => "K&#46; Falke"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:6 [
                        "tituloSerie" => "Intensive Care Med"
                        "fecha" => "1995"
                        "volumen" => "21"
                        "paginaInicial" => "554"
                        "paginaFinal" => "560"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/7593896"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            18 => array:3 [
              "identificador" => "bib0095"
              "etiqueta" => "19"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Evaluaci&#243;n de la medida de la presi&#243;n de oclusi&#243;n incorporada en los ventiladores Evita"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:5 [
                            0 => "M&#46; Subirana"
                            1 => "C&#46; Irrazabal"
                            2 => "E&#46; Bak"
                            3 => "F&#46; Jara"
                            4 => "J&#46; Mancebo"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "Med Intensiva"
                        "fecha" => "1997"
                        "volumen" => "21"
                        "paginaInicial" => "305"
                        "paginaFinal" => "310"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            19 => array:3 [
              "identificador" => "bib0100"
              "etiqueta" => "20"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Improved efficacy of spontaneous breathing with inspiratory pressure support"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:3 [
                            0 => "L&#46; Brochard"
                            1 => "F&#46; Pluskwa"
                            2 => "F&#46; Lemaire"
                          ]
                        ]
                      ]
                    ]
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                        "paginaInicial" => "411"
                        "paginaFinal" => "415"
                        "link" => array:1 [
                          0 => array:2 [
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              "identificador" => "bib0105"
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                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Familial aspects of ventilatory control in patients with chronic obstructive pulmonary disease"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:3 [
                            0 => "J&#46;A&#46; Fleetham"
                            1 => "M&#46;E&#46; Arnup"
                            2 => "N&#46;R&#46; Anthonisen"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1164/arrd.1984.129.2P2.S3"
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                        "tituloSerie" => "Am Rev Respir Dis"
                        "fecha" => "1984"
                        "volumen" => "129"
                        "paginaInicial" => "3"
                        "paginaFinal" => "7"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/6422810"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            21 => array:3 [
              "identificador" => "bib0110"
              "etiqueta" => "22"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Effects of aging on ventilatory and occlusion pressure responses to hypoxia and hypercapnia"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:4 [
                            0 => "D&#46;D&#46; Peterson"
                            1 => "A&#46;I&#46; Pack"
                            2 => "D&#46;A&#46; Silage"
                            3 => "A&#46;P&#46; Fishman"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1164/arrd.1981.124.4.387"
                      "Revista" => array:6 [
                        "tituloSerie" => "Am Rev Respir Dis"
                        "fecha" => "1981"
                        "volumen" => "124"
                        "paginaInicial" => "387"
                        "paginaFinal" => "391"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/7294501"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
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              "identificador" => "bib0115"
              "etiqueta" => "23"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "An endogenous circadian rhythm of respiratory control in humans"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:3 [
                            0 => "C&#46;M&#46; Spengler"
                            1 => "C&#46;A&#46; Czeisler"
                            2 => "S&#46;A&#46; Shea"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:6 [
                        "tituloSerie" => "J Physiol"
                        "fecha" => "2000"
                        "volumen" => "526 Pt 3"
                        "paginaInicial" => "683"
                        "paginaFinal" => "694"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/10922018"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            23 => array:3 [
              "identificador" => "bib0120"
              "etiqueta" => "24"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Effects of hypercapnia and inspiratory flow-resistive loading on respiratory activity in chronic airways obstruction"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:4 [
                            0 => "M&#46;D&#46; Altose"
                            1 => "W&#46;C&#46; McCauley"
                            2 => "S&#46;G&#46; Kelsen"
                            3 => "N&#46;S&#46; Cherniack"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1172/JCI108665"
                      "Revista" => array:6 [
                        "tituloSerie" => "J Clin Invest"
                        "fecha" => "1977"
                        "volumen" => "59"
                        "paginaInicial" => "500"
                        "paginaFinal" => "507"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/838862"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            24 => array:3 [
              "identificador" => "bib0125"
              "etiqueta" => "25"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Hypoventilation in obstructive lung disease&#46; The role of familial factors"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:3 [
                            0 => "R&#46; Mountain"
                            1 => "C&#46; Zwillich"
                            2 => "J&#46; Weil"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1056/NEJM197803092981001"
                      "Revista" => array:6 [
                        "tituloSerie" => "N Engl J Med"
                        "fecha" => "1978"
                        "volumen" => "298"
                        "paginaInicial" => "521"
                        "paginaFinal" => "525"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/625307"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            25 => array:3 [
              "identificador" => "bib0130"
              "etiqueta" => "26"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Hyperoxic-induced hypercapnia in stable chronic obstructive pulmonary disease"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:3 [
                            0 => "C&#46;S&#46; Sassoon"
                            1 => "K&#46;T&#46; Hassell"
                            2 => "C&#46;K&#46; Mahutte"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:6 [
                        "tituloSerie" => "Am Rev Respir Dis"
                        "fecha" => "1987"
                        "volumen" => "135"
                        "paginaInicial" => "907"
                        "paginaFinal" => "911"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/3565937"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            26 => array:3 [
              "identificador" => "bib0135"
              "etiqueta" => "27"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Effects of the administration of O2 on ventilation and blood gases in patients with chronic obstructive pulmonary disease during acute respiratory failure"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => true
                          "autores" => array:6 [
                            0 => "M&#46; Aubier"
                            1 => "D&#46; Murciano"
                            2 => "J&#46; Milic-Emili"
                            3 => "E&#46; Touaty"
                            4 => "J&#46; Daghfous"
                            5 => "R&#46; Pariente"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1164/arrd.1980.122.5.747"
                      "Revista" => array:6 [
                        "tituloSerie" => "Am Rev Respir Dis"
                        "fecha" => "1980"
                        "volumen" => "122"
                        "paginaInicial" => "747"
                        "paginaFinal" => "754"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/6778278"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            27 => array:3 [
              "identificador" => "bib0140"
              "etiqueta" => "28"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Contribution of the Haldane effect to the rise of arterial Pco2 in hypoxic patients breathing oxygen"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:4 [
                            0 => "U&#46;C&#46; Luft"
                            1 => "E&#46;M&#46; Mostyn"
                            2 => "J&#46;A&#46; Loeppky"
                            3 => "M&#46;D&#46; Venters"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:6 [
                        "tituloSerie" => "Crit Care Med"
                        "fecha" => "1981"
                        "volumen" => "9"
                        "paginaInicial" => "32"
                        "paginaFinal" => "37"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/6780265"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            28 => array:3 [
              "identificador" => "bib0145"
              "etiqueta" => "29"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Carbon dioxide response lines in young adults&#58; the limits of the normal response"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:1 [
                            0 => "G&#46;B&#46; Irsigler"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1164/arrd.1976.114.3.529"
                      "Revista" => array:6 [
                        "tituloSerie" => "Am Rev Respir Dis"
                        "fecha" => "1976"
                        "volumen" => "114"
                        "paginaInicial" => "529"
                        "paginaFinal" => "536"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/970734"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            29 => array:3 [
              "identificador" => "bib0150"
              "etiqueta" => "30"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Normal values for hypoxic and hypercapnic ventilatory drives in man"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:3 [
                            0 => "C&#46;A&#46; Hirshman"
                            1 => "R&#46;E&#46; McCullough"
                            2 => "J&#46;V&#46; Weil"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:6 [
                        "tituloSerie" => "J Appl Physiol"
                        "fecha" => "1975"
                        "volumen" => "38"
                        "paginaInicial" => "1095"
                        "paginaFinal" => "1098"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/1141125"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            30 => array:3 [
              "identificador" => "bib0155"
              "etiqueta" => "31"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Variability of ventilatory responses to hypoxia and hypercapnia"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:6 [
                            0 => "S&#46;A&#46; Sahn"
                            1 => "C&#46;W&#46; Zwillich"
                            2 => "N&#46; Dick"
                            3 => "R&#46;E&#46; McCullough"
                            4 => "S&#46; Lakshminarayan"
                            5 => "J&#46;V&#46; Weil"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:6 [
                        "tituloSerie" => "J Appl Physiol"
                        "fecha" => "1977"
                        "volumen" => "43"
                        "paginaInicial" => "1019"
                        "paginaFinal" => "1025"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/606686"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            31 => array:3 [
              "identificador" => "bib0160"
              "etiqueta" => "32"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Comparison of occlusion pressure and ventilatory responses"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:4 [
                            0 => "D&#46;H&#46; Lederer"
                            1 => "M&#46;D&#46; Altose"
                            2 => "S&#46;G&#46; Kelsen"
                            3 => "N&#46;S&#46; Cherniack"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:6 [
                        "tituloSerie" => "Thorax"
                        "fecha" => "1977"
                        "volumen" => "32"
                        "paginaInicial" => "212"
                        "paginaFinal" => "220"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/867336"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            32 => array:3 [
              "identificador" => "bib0165"
              "etiqueta" => "33"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Clinical characteristics&#44; respiratory functional parameters&#44; and outcome of a two-hour T-piece trial in patients weaning from mechanical ventilation"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:6 [
                            0 => "I&#46; Vallverd&#250;"
                            1 => "N&#46; Calaf"
                            2 => "M&#46; Subirana"
                            3 => "A&#46; Net"
                            4 => "S&#46; Benito"
                            5 => "J&#46; Mancebo"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1164/ajrccm.158.6.9712135"
                      "Revista" => array:6 [
                        "tituloSerie" => "Am J Respir Crit Care Med"
                        "fecha" => "1998"
                        "volumen" => "158"
                        "paginaInicial" => "1855"
                        "paginaFinal" => "1862"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/9847278"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            33 => array:3 [
              "identificador" => "bib0170"
              "etiqueta" => "34"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "A prospective&#44; blinded evaluation of indexes proposed to predict weaning from mechanical ventilation"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => true
                          "autores" => array:6 [
                            0 => "G&#46; Conti"
                            1 => "L&#46; Montini"
                            2 => "M&#46;A&#46; Pennisi"
                            3 => "F&#46; Cavaliere"
                            4 => "A&#46; Arcangeli"
                            5 => "M&#46;G&#46; Bocci"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1007/s00134-004-2230-8"
                      "Revista" => array:6 [
                        "tituloSerie" => "Intensive Care Med"
                        "fecha" => "2004"
                        "volumen" => "30"
                        "paginaInicial" => "830"
                        "paginaFinal" => "836"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/15127195"
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                          ]
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                      ]
                    ]
                  ]
                ]
              ]
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ISSN: 02105691
Idioma original: Inglés

DOI:10.1016/j.medin.2013.10.004

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