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Nutritional support and refeeding syndrome in critical illness

Refeeding syndrome occurs with the reintroduction of food after an individual has undergone a substantial period of malnutrition. The development of this condition is not uncommon but is neglected in most cases.

To identify the incidence of refeeding syndrome in hospitalized patients undergoing total parenteral nutrition and factors that may be associated with this condition.

Observational retrospective and prospective cohort study. Data collection took place at the Hospital de Clínicas de Porto Alegre, from 2015 to 2018. Data was collected consecutively from patient electronic medical records. All hospitalized individuals aged 18 years or more and having a prescription for total parenteral nutrition were included in the study. Exclusion criteria included patients with diabetic ketoacidosis; receiving renal replacement therapy or chronic kidney disease with a glomerular filtration rate <30 mL/min; severe metabolic acidosis or any disease that could affect serum phosphorus levels. WinPepi software, version 11.65, was used to calculate sample size. Data analysis was performed using SPSS version 20.0. A 5% significance level was considered for the established comparisons. The project was approved by the Research Ethics Committee of Hospital de Clínicas de Porto Alegre (number 17–0313).

Data from 97 patients was collected. The incidence of refeeding syndrome in our sample was 43.3% (n = 42). Factors positively associated with the syndrome were use of standard parenteral nutrition (p < 0.01), advancing age (mean 62.8 yr versus 55.1 yr; p = 0.013), and amount of total energy administered, which were 25.6 kcal/kg/day versus 23.6 kcal/kg/day for patients with and without refeeding syndrome, respectively (p < 0.01).

The incidence of refeeding syndrome in individuals using total parenteral nutrition was high. The supply of a greater quantity of total energy in the first week of nutritional therapy, the absence of electrolytes in the parenteral nutrition solution and advancing age were all factors associated with the emergence of refeeding syndrome.

Neurocritically ill patients are more likely to be comatose and suffer from dysphagia, conditions that inevitably require nutritional support. Inappropriate nutritional support may lead to refeeding syndrome (RFS). This study aimed to explore the incidence and outcome of RFS in neurocritically ill patients.

We conducted a retrospective study among neurocritically ill patients who received total enteral nutrition for >72 h in a university-affiliated hospital. RFS was defined as the occurrence of new-onset hypophosphatemia (<0.65 mmol/L) within 72 h of the commencement of nutritional support. The primary outcome was 6-month mortality. The secondary outcomes included 30-day mortality, neurocritical care unit (NCU) stay, and hospital length of stay.

A total of 328 patients were enrolled, and 56 (17.1%) of them developed RFS within 72 h of nutrition support. Significantly, we found that patients with high malnutrition universal screening tool (MUST) and sequential organ failure assessment (SOFA) scores were more likely to develop RFS. The occurrence of RFS was associated with a longer NCU stay, higher 30-day mortality and 6-month mortality, and poorer 6-month functional outcome. Moreover, RFS was identified as an independent risk factor for 6-month mortality.

RFS is not rare in neurocritically ill patients and is more likely to occur in patients with nutritional risk and more severe conditions. RFS is an independent risk factor for 6-month mortality in neurocritically ill patients.

Refeeding syndrome can result following excessive feeding of malnourished patients. The syndrome remains poorly defined but encompasses a range of adverse effects including electrolyte shifts, hyperglycaemia and other less well-defined phenomena. There are additional risks of underfeeding malnourished individuals. Studies of refeeding syndrome have generally focussed on critical care environments or patients with anorexia nervosa. Here we have conducted a two-centre, prospective, double-blind, randomised controlled trial amongst all patients referred to hospital nutrition support teams for intravenous nutrition support. We sought to determine whether electrolyte and other abnormalities suggestive of refeeding syndrome risk varied depending on initial rate of intravenous feeding.

Patients at moderate or high risk of refeeding syndrome, as defined by United Kingdom National Institute of Health and Care Excellence guidelines, were screened for inclusion. Patients were randomised to receive either high (30 kcal/kg/day, 0.25 gN/kg/day) or low (15 kcal/day, 0.125 gN/kg/day) rate feeding for the first 48 h prior to escalation to standard parenteral nutrition regimens. The primary outcome was rates of potential refeeding risks within the first 7 days as defined by electrolyte imbalance or hyperglycaemia requiring insulin. Secondary outcomes included effects on QTc interval, infections and length of hospital stay. Statistical analysis was performed with χ² or Wilcoxon rank sum tests and all analysis was intention-to-treat. Problems with study recruitment led to premature termination of the trial. Registered on the EU Clinical Trials Register (EudraCT number 2007-005547-17).

534 patients were screened and 104 randomised to either high or low rate feeding based on risk of refeeding syndrome. Seven patients were withdrawn prior to collection of baseline demographics and were excluded from analysis. 48 patients were analysed for the primary outcome with potential refeeding risks identified in 46%. No differences in risks were seen between high and low rate feeding (p > 0.99) or high and moderate risk feeding (p = 0.68). There were no differences in QTc abnormalities, infection rates, or hospital length of stay between groups.

In this randomised trial of rates of refeeding risk, in patients pre-stratified as being at high or moderate risk, we found no evidence of increased refeeding related disturbances in those commenced on high rate feeding compared to low rate. No differences were seen in secondary endpoints including cardiac rhythm analysis, infections or length of stay. Our study reflects real world experience of patients referred for nutrition support and highlights challenges encountered when conducting clinical nutrition research.

The principal purpose of critical care nutrition is to arrest the loss of lean body mass and to maintain and restore energy-dependent homeostatic functions. There is no well-validated tool that evaluates the nutritional status of the critically ill patient, so opinion-based clinical evaluation of nutritional status is preferred. There is no evidence that parenteral nutrition (PN) is superior to enteral nutrition (EN) during the first 7 days of critical illness and vice versa. Moreover, early EN and early PN feeding do not appear to improve outcomes compared with delayed or hypocaloric nutrition. Parenteral nutrition should probably be delayed for up to 7 days for well-nourished patients. Adding PN to EN early in critical illness to achieve energy goals does not improve outcomes. The status of PN in malnourished or undernourished patients is unclear. PN is not associated with elevated infection risk. EN is associated with gastrointestinal complications, principally vomiting, probably clinically insignificant. EN is safe to administer to patients receiving vasoactive drugs after the initial shock period. For the majority of patients, gastric feeding should be attempted, and this usually results in achieving nutritional goals. It is probably unnecessary to routinely check gastric residual volumes. EN is superior to PN in patients with acute pancreatitis. In conclusion, there is currently no evidence that administration of a patient’s full estimated energy requirements improves outcomes in early critical illness. Consequently, trophic or hypocaloric feeding is a reasonable approach in the first 7 days.

El proyecto denominado «Compromiso por la calidad de las sociedades científicas» impulsado desde el año 2013 por el Ministerio de Sanidad, Servicios Sociales e Igualdad tiene como objetivo disminuir las intervenciones sanitarias innecesarias que no han demostrado eficacia, tienen escasa o dudosa efectividad o no son eficientes. El objetivo de este trabajo es elaborar las recomendaciones de «qué no hacer» seleccionadas para el tratamiento de los pacientes críticos. Se designó un panel de expertos de los 13 grupos de trabajo (GT) de la Sociedad Española de Medicina Intensiva, Crítica y Unidades Coronarias (SEMICYUC), elegido por su experiencia clínica o científica para la realización de las recomendaciones. Se analizó la literatura publicada entre los años 2000 y 2017 sobre diferentes cuestiones asociadas a los pacientes críticos. En reuniones de cada GT, los expertos debatieron las propuestas y sintetizaron las conclusiones, que fueron finalmente aprobadas por los GT después de un amplio proceso de revisión interna, realizado durante el primer semestre de 2017. Finalmente, se elaboraron un total de 65 recomendaciones, 5 por cada uno de los 13 GT. Estas recomendaciones se basan en la opinión de expertos y en el conocimiento científico, y pretenden reducir aquellos tratamientos o procedimientos que no aporten valor al proceso asistencial, evitar la exposición de los pacientes críticos a potenciales riesgos y mejorar la adecuación de los recursos sanitarios.

The project “Commitment to Quality of Scientific Societies”, promoted since 2013 by the Spanish Ministry of Health, seeks to reduce unnecessary health interventions that have not proven effective, have little or doubtful effectiveness, or are not cost-effective. The objective is to establish the “do not do” recommendations for the management of critically ill patients. A panel of experts from the 13 working groups (WGs) of the Spanish Society of Intensive and Critical Care Medicine and Coronary Units (SEMICYUC) was selected and nominated by virtue of clinical expertise and/or scientific experience to carry out the recommendations. Available scientific literature in the management of adult critically ill patients from 2000 to 2017 was extracted. The clinical evidence was discussed and summarized by the experts in the course of consensus finding of each WG, and was finally approved by the WGs after an extensive internal review process carried out during the first semester of 2017. A total of 65 recommendations were developed, of which 5 corresponded to each of the 13 WGs. These recommendations are based on the opinion of experts and scientific knowledge, and aim to reduce those treatments or procedures that do not add value to the care process; avoid the exposure of critical patients to potential risks; and improve the adequacy of health resources.

Le syndrome de renutrition inappropriée, souvent méconnu, représente l’ensemble des troubles biologiques et leurs complications cliniques, survenant au cours d’une réalimentation chez des malades dont les réserves nutritionnelles sont altérées. Ces complications morbides peuvent être fatales. La stratégie de prise en charge passe par une identification des patients à risque, et une renutrition progressive associée à une surveillance étroite des troubles biologiques et leur correction précoce.

Refeeding syndrome, often overlooked, encompasses electrolyte disturbances and clinical consequences, which may occur in undernourished patients during refeeding. Clinical complications are potentially fatal. Identification of patients who are at risk of developing refeeding syndrome is crucial. Initiation of refeeding should be moderate and slow. Monitoring and correction of electrolytes disturbances should be strict.