Risk Factors of Extubation Failure in PICU Patients

Mechanical ventilation (MV) is a common life support modality in 40% of pediatric intensive care unit (PICU) patients. The process of ventilatory support follows a continuum of care, beginning with the patient requiring initial support and ending with the ability to sustain spontaneous breathing [1].

Although MV is a cornerstone in critical care medicine, risks and complications associated with prolonged MV include ventilator associated pneumonia (VAP), barotrauma / volutrauma, decreased cardiac filling, ventilator associated diaphragmatic dysfunction and sepsis [6, 8].

Previous studies recommend extubating patient as early as possible according to clinical course and reversal of the leading causes of intubation. The process of extubation consists of the removal of the endotracheal tube when the patient's physiological status recovers allowing the patient to maintain spontaneous breathing [3,4].

Weaning from MV and extubation are vital steps in patients' recovery; however, these steps are associated with significant risks. Balancing the hazards of premature extubation such as extubation failure (EF) and emergent reintubation with those of prolonged MV is a challenge. [4,5] There is currently a paucity of published evidence-based protocols or guidelines to guide this process; therefore, predictors for successful extubation in critically ill children are not always clear cut. This has resulted in wide variation in practice amongst (PICU) providers that is typically based on institutional norms [4,5, 6]. The most common approach to weaning infants and children is gradual reduction of ventilatory settings not requiring changing the ventilator mode [12].

Up to 20% of MV patients experience EF [10]. EF is defined as the need to reinsert the endotracheal tube to resume MV in patients extubated for less than 48 hours. It has high rates of morbidity and mortality, prolongs the duration of MV and thus causes a longer stay in the PICU and risk of complications such as the need for tracheostomy, the incidence of pneumonia and pulmonary damage, and finally, costs increase as well and death [10, 11] .

At present , several pediatric studies have shown the predictive factors associated with EF ; longer duration of MV ≥7 days and PICU admission ≥ one month , age under one year , malnutrition, respiratory and chronic neurological deterioration , use of sedatives by infusion ≥ 5 days and inotropes ≥ 10 days[6,8] , improper evaluation for extubation readiness , post extubation upper airway obstruction and stridor, residual muscle weakness , pulmonary edema , weak cough reflex[9, 10] , use of uncuffed endotracheal tube , presence of any metabolic and electrolyte imbalances and high ventilator settings prior to extubation [11].

Therapeutic respiratory support, including noninvasive positive pressure ventilation and high-flow nasal cannula, appears to help reduce the need for reintubation in the majority of patients experiencing post extubation respiratory failure. however, Neurologic patients seem to be at higher risk of reintubation despite NIV use [6,13].

Previous researches were carried out in some Egyptian PICUs to investigate the incidence and potential risk factors of EF [1,2,3]. Mahmoud demonstrated that about third of mechanically-ventilated patients in the study experienced EF [2]. Another study showed that the need for longer periods of sedation and high setting on MV in addition to excess tracheal secretions were among strong predictors for EF [3]. Moreover, previous research in our PICU indicated that mortality was high up to 40% [16]. Therefore, investigating the causes of EF in our unit might help in reducing mortality. Furthermore, establishing local protocol of gradual and correct weaning can decrease the risk of EF in our unit.