Prolonged mechanical ventilation (PMV) in adults is defined as needing ≥21 consecutive days of invasive (INV) or noninvasive (NIV) mechanical ventilation (MV) for ≥6 h/day with a maximum of 48 h without MV.1 In the case of children, there is no consensus, but ≥14 days or ≥21 days have been proposed depending on the authors.2–4 Long-term MV, on the other hand, is defined as MV maintained for more than three months, including home MV.5

In recent decades, PMV in the Pediatric Intensive Care Unit (PICU) has increased due to scientific and technological advances and changes in ethical and social criteria affecting the chronically ill population, which is growing in number and survival.6–8 A recent prospective study conducted in 158 PICUs included 14,595 patients from 28 countries, showing a prevalence of PMV of 18.3% in children and adolescents admitted to the PICU,9 which is more than double the figures reported by previous single-center, retrospective studies.10 These patients consume numerous healthcare resources and are at high risk of complications (mainly pneumonia) and mortality.7,9 Reported mortality rates are highly variable (18.2–30%, depending on the series) and are influenced by follow-up time, severity, and regional considerations, such as the resources allocated to long-term MV or the ethical criteria applied in decision-making.6,9 Likewise, the emotional and logistical impact of PMV on families is enormous. Typically, one parent, usually the mother, assumes the role of primary caregiver.11 The present article describes the characteristics of these patients, technical aspects related to MV and tracheostomy (TC), weaning strategies, transition to home, and treatment outcomes. The content focuses on the PICU setting and does not address elective PMV initiated outside the PICU.

Children and adolescents with PMV constitute a very heterogeneous group of patients. From a pathophysiological perspective, such cases can be grouped into three clinical syndromes: increased respiratory load, respiratory pump failure, and failure of neurological control of breathing.12 Patients commonly experience several pathophysiological mechanisms over the course of the disorder. Thus, neuromuscular diseases progress from an initial stage of being unable to cope with the increased respiratory load due to infection to a second stage characterized by progressive respiratory pump failure (with alveolar hypoventilation). In the case of degenerative diseases of the central nervous system (CNS), this progresses to a third stage involving failure of the neurological control of breathing. In other disorders, such as severe chronic lung disease secondary to prematurity, oncohematological disease, and heart diseases, increased respiratory load is the primary mechanism. Finally, the growing group of genetic or chromosomal disorders may combine several injury mechanisms13–19 (Table 1). Although the data show regional differences, the diseases most frequently associated with the need for PMV in the PICU are congenital heart diseases, followed by bronchopulmonary dysplasia and neuromuscular disorders. Oncohematological diseases account for approximately 10% of all cases.9

Due to the complications associated with the use of the different invasive and noninvasive mechanical ventilation modalities, withdrawal from ventilation should be considered as soon as it becomes possible.25 Despite the existence of guidelines for weaning patients from mechanical ventilation,26 their effective application remains limited.27

Current recommendations include conducting periodic systematized evaluations seeking to determine if a patient is potentially ready for extubation.26 Extubation adequacy testing forms part of these evaluations.28,29 In general, these evaluations include:

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  Variables related to the underlying disease that require the initiation of MV.

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  Physiological variables aimed at assessing respiratory function.

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  Variables related to ventilator parameters.

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  Other patient-related variables, such as neurological status, sedation level, muscle function, and hemodynamic status. The patient must have an adequate level of sedation, an effective cough, and adequate secretions management in order to be considered suitable for extubation.26,30 Unfortunately, the best tools for identifying these situations have not been clearly defined. One method of assessing muscle strength is to determine peak inspiratory pressure (PImax) using a manometer connected to the endotracheal tube while temporarily occluding the tube. This method can be used to identify the presence of adequate muscle capacity. Values of PImax higher than −30 to −50 cmH2O have been proposed as predictors of weaning success, depending on age.26,31,32

Any protocol or systematic evaluation aimed at facilitating weaning from mechanical ventilation should consider the existence of patients at high risk of extubation failure.30 Early determination of the patient's suitability for extubation may result in a better prognosis. In recent years, the potential usefulness of automated assessment tools has been suggested.

Spontaneous breathing trials are widely used in the PICU setting.28,29 These trials are used to evaluate patient suitability for extubation by assessing respiratory effort under conditions similar to those which the patient would experience upon extubation. This evaluation aims to reduce the degree of respiratory support. These trials temporarily establish minimum ventilatory parameters to assess respiratory function and work.26 However, there are conflicting results regarding the use of minimal pressure support in pediatrics to overcome endotracheal tube resistance and whether continuous positive airway pressure (CPAP) adequately predicts respiratory effort after extubation.26,33,34 There is also a lack of consensus on the most appropriate duration of these trials.35–37 Most authors emphasize the need for more demanding and prolonged spontaneous breathing trials in patients at higher risk for extubation failure.23,26

Post-extubation upper airway obstruction is one of the most common causes of extubation failure in pediatric patients, accounting for up to 50% of cases.30 For this reason, prevention and risk assessment are important. Deflating the cuff during air leak testing could identify patients at higher risk, although no criteria have been defined for its use.26 The possible use of laryngeal ultrasound has also been proposed.32 There is evidence that corticosteroids (usually dexamethasone) are effective in preventing inflammatory upper airway obstruction. Administering high doses (>0.5 mg/kg/dose) at least 6 h before extubation could be associated with better results.26,38 Nevertheless, recommendations state that once a patient is deemed suitable for extubation, extubation should not be delayed to initiate corticosteroid treatment.26

Over the past decade, the use of neurally adjusted ventilatory assist (NAVA) has been proposed as a method to facilitate weaning from invasive and noninvasive ventilatory support. Several studies have been conducted in children, particularly neonates,39 but also in older patients.40,41 Although NAVA is not widely available and is costly, it has been shown to reduce asynchronies, potentially making it especially useful in patients in whom asynchronies are a significant factor.41

TC may facilitate weaning from PMV by enabling decreased sedoanalgesia and better adaptation. Some studies have reported shorter MV and admission times in pediatric patients with early TC.42 In the international study published by Kawaguchi et al., up to 29.8% of patients were tracheostomized before 14 days of MV, with a median time of 26 days.9 Conversely, TC may facilitate discharge from the PICU to less complex care settings or to home.

Another critical factor in successfully withdrawing from PMV is the post-extubation use of NIV. Current recommendations suggest the systematic use of CPAP or BiPAP for patients at risk of extubation failure.26 HFO appears to be less effective in this context,43 and its use is therefore discouraged, especially in children under one year of age.26 It is also recommended that support be escalated early for patients who are extubated to conventional oxygen therapy and show signs of respiratory distress.26

TC is a technique that is commonly used in children, including infants under one year of age. The TC cannula provides a stable artificial airway, resolving anatomical or functional airway obstruction (as occurs in severe tracheomalacia). It also allows for PMV and secretions management.44

Types of tracheostomy tubes

The type and size of the cannula should be personalized based on the patient's age, reason for tracheostomy (TC), tracheal anatomy, and use of mechanical ventilation or a speaking valve (Fig. 1). In general, one-piece cannulas without a balloon or cuff49 are used in pediatrics, usually made of plastic or silicone (exceptionally, silver). The size corresponds to the internal diameter (ID). Cannulas that occupy no more than two-thirds of the tracheal lumen are recommended to prevent lesions and enable phonatory translaryngeal flow. A small cannula is preferable if it achieves the intended purpose (i.e., a patent airway and adequate ventilation). The distal end of the cannula should be positioned concentrically and collinearly with the trachea; otherwise, there is a risk of esophageal obstruction, sudden obstruction by the tracheal wall, wall erosion, innominate artery damage, or tracheoesophageal fistula.49,50

Figure 1.

Different types of tracheostomy tubes.50 Cannulas with a cuff: (A) Air and straight flange; (B) Foam and V-shaped flange; (C) Saline solution, tight to shaft (TTS), when deflated, it remains totally attached to the cannula without restricting flow. (D) Two-piece cannula (external and internal) with cuff and straight flange, available from an internal diameter of 6. (E) Customized cannula, without cuff, straight flange, and with flexible extension at the proximal end. (F) The flexible extension allows connection of the ventilator circuits away from the stoma. This is especially useful when access to the neck is difficult, such as with infants, small children, or spinal cord injury patients with immobilizing halo braces. It can also prevent airflow from entering through the fresh sutures of the stoma if the patient is disconnected. (G) Cuff-less cannula of adjustable length, with flexible internal extension and external extension. (H) Fenestrated cannula. Fenestrated cannulas are rarely used in children because they increase resistance to flow (since they have 2 pieces) and favor the formation of granulomas at the fenestration. Additionally, small sizes are not manufactured. (I) Cannula with cuff and subglottic suction channel to minimize microaspiration, available for adults.

Source: Reproduced with the permission of García Teresa and Leoz.50

Cannulas without a cuff or with a deflated cuff are typically used to enable phonation and facilitate swallowing. The absence of a cuff makes tidal volume alarms unnecessary, but low minute volume alarms (less than 1 l/min) can remain. Cuff-equipped cannulas are indicated for the following: a) to optimize ventilation in cases of severe respiratory disease; b) during the first 5–7 days postoperatively, to prevent complications from air entering through the recent sutures if MV is used; and c) to prevent chronic translaryngeal aspiration. This latter indication is currently being questioned.51

Some companies allow cannulas to be customized (made longer or with a special curvature) for patients with special needs, such as children with distal tracheomalacia that is not covered by the standard length. Customizing the cannulas ensures optimal ventilation and comfort.

Several studies have demonstrated the importance of ensuring adequate nutrition for pediatric patients undergoing mechanical ventilation.65–68 Recommendations for the non-respiratory management of pediatric patients with acute respiratory distress syndrome (ARDS)69 have recently been published. These recommendations include the early introduction of enteral nutrition (EN) before 72 h and the use of targeted nutritional protocols to ensure caloric intake that covers basal needs, facilitates recovery, and maintains growth. For these patients, it is advised that at least 1.5 g/kg/day of protein be provided. The administration route may range from a nasogastric tube to a transpyloric tube. Over the long term, a gastrostomy may be necessary, with or without antireflux surgery. In some patients, TC allows for oral intake.

Regarding rehabilitation strategies, these guidelines recommend maintaining circadian patterns of activity and rest, as well as setting activity and mobilization goals. Rehabilitation should be personalized and coordinated by multidisciplinary teams that assess the initial condition, establish goals, and determine the optimal time to start rehabilitation.69 Respiratory physiotherapy techniques, such as increased expiratory flow, manual hyperinflation, and vibrations, have proven useful in managing secretions, which is particularly important for neuromuscular patients dependent on mechanical ventilation.70 Speech therapists play a fundamental role in phonatory and dysphagia rehabilitation.

In recent years, the significant role of families in caring for pediatric patients with PMV has become evident.71–73 Beyond their importance in providing daily care during hospital admission and at home, the most recent recommendations advocate for the direct involvement of parents in decision-making related to the use of PMV in children.74,75 The care team must combine its experience and knowledge with an understanding of the patients' and their families' values, beliefs, and expectations. Open, empathetic, and unbiased communication is essential between all parties involved in the process. Rather than making decisions in a single encounter, they should be approached in a thoughtful manner over time. A critical issue is assessing the family's understanding of the disease, the therapeutic options, and the implications of caring for a child subjected to prolonged ventilation.

The transition to home is very different for children who are on life-sustaining mechanical ventilation (PMV), either tracheostomized or receiving NIV for more than 16 h per day, compared to those who receive elective NIV, usually at night.

The PICU should incorporate strategies that have already proven effective in the management of preterm infants, such as NAVA NIV or the kangaroo care method.76 Different interfaces can be selected for patients with NIV, depending on age, weight, and severity.23

In general, patients who cannot tolerate short resting periods due to bilateral diaphragmatic paralysis, experience airway collapse with rapid deterioration associated with tracheomalacia, or have frequent sudden episodes of cyanosis due to severe breath-holding spells associated with Ondine's disease should not receive NIV support. Instead, they should undergo tracheostomy immediately to ensure their safety.77

Before scheduling the transition home, it is essential to stabilize the patient adequately on the hospital ventilator. Transitioning to a home ventilator can be challenging for patients weighing less than 6 kg, especially infants with bronchopulmonary dysplasia. This requires careful selection of the ventilator and precise adjustment of its settings.78 Currently, only a few home ventilators can support patients weighing less than 5 kg.

The standards for training and assessing family caregiver competency vary among institutions. Families and their medical teams should agree on minimum safety preparations, materials, and the number of trained individuals responsible for care at home (Table 5). For IMV, it is recommended that at least two family caregivers receive full training in all aspects of care before the patient is discharged. In addition to daily hands-on training with the patient, simulation sessions can improve management of situations such as cannula obstruction or aspiration.77

The long-term therapeutic objectives of PMV are to prolong life, improve quality of life, and prevent the deterioration of lung function or respiratory exacerbations. PMV is currently a realistic alternative to death due to respiratory failure for many children with chronic respiratory disease, and the most obvious benefit of this technique is increased life expectancy.6,79 Some patients, especially those diagnosed with chronic lung or airway disease, can be weaned off of PMV.55,80 Additionally, elective PMV reduces respiratory infections, complications due to secretions, decompensation episodes, and the number and duration of hospital admissions.15,22

The mortality rate is higher for children with PMV than for healthy children. However, it is not possible to determine if this increase is due to the progression of the underlying disease, chronic respiratory failure that cannot be compensated for by respiratory support, inadequate therapeutic efforts in situations of worsening, or complications intrinsically related to PMV.4,6,9,80,81 Several studies have reported an increased risk of fatal accidents in PMV patients due to TC, resulting from accidental decannulation or cannula obstruction.53–55,81 PMV is associated with increased mortality during admission to the PICU due to the impossibility of extubation, accidental extubation with the impossibility of reintubation, infections, and other healthcare-related complications.79,81

Infectious complications are primarily associated with IMV. Tracheobronchitis is the most common complication, and VAP is the most serious complication.79 IMV is associated with lung and airway injuries, particularly at the laryngeal and tracheal levels. Using a clamped endotracheal tube with pressure above 20−25 mmHg can result in tracheal mucosal injury and lead to symptomatic subglottic stenosis.79 Additionally, using an endotracheal tube with inadequate sedation can result in laryngeal injury. The most significant pulmonary complication is ventilation-induced lung injury (VILI). It is associated with elevated tidal volume, driving pressure, flow, and respiratory rate. To a lesser extent, VILI is related to increased PEEP, resistance, and elastance.79 Sedatives and muscle relaxants can produce complications such as withdrawal syndrome, delirium, myopathy, neuropathy, and diaphragmatic dysfunction. TC can significantly reduce the need for these drugs.45

The most common complications associated with PMV and NIV include pressure ulcers caused by interfaces, conjunctival irritation due to uncontrolled leaks, and facial deformities caused by continuous pressure from straps and masks.23,82

PMV can affect feeding methods, making an enteral tube or gastrostomy obligatory for intubated patients.55,79

Children with PMV require costly healthcare resources7 (technology and specialized personnel) and a great deal of family and social support. The impact on the mental health and quality of life of family members (parents and siblings) is negative due to the increased care burden. For the same condition and severity, patients with PMV perceive a better quality of life than patients without it. However, parents tend to have a poorer impression of their child’s quality of life than the patient does.11

In conclusion, PMV in the PICU is a growing technique with specific characteristics that differ from conventional mechanical ventilation, both materially and technically. Personnel involved in managing pediatric patients with PMV must have specific knowledge to use this technique effectively.

Design, preparation, and revision of the manuscript: all authors. Coordination: María Ángeles García Teresa.

AI has not been used.

The authors state that the present study has received no funding.