The endotracheal tube air leak test does not predict extubation outcome in critically ill pediatric patients

Abstract

Objective: Endotracheal tube air leak pressures (ALT) are used to predict post-extubation upper airway compromise such as stridor, upper airway obstruction, or risk of reintubation. To determine if the absence of an endotracheal tube air leak (ALT ≥ 30 cm H 2 O) measured during the course of mechanical ventilation predicts extubation failure in infants and children.Design: Prospective, blinded cohort. Setting:Multidisciplinary pediatric intensive care unit of a university hospital. Patients: Patients age ≤ 18 years and intubated ≥ 24 hoursInterventions-The pressure required to produce an audible endotracheal tube air leak was measured within 12 hours of intubation and extubation. Unless prescribed by the medical care team, patients did not receive neuromuscular blocking agents during ALT measurements. Measurements and Main Results:The need for reintubation (i.e., extubation failure) was recorded during the 24 hour post-extubation period. Seventy-four patients were enrolled resulting in 59 observed extubation trials. The extubation failure rate was 15.3% (9/59). Seven patients were treated for post-extubation stridor. Extubation failure was associated with a longer median length of ventilation, 177 vs. 78 hours, p=0.03. Extubation success was associated with the use of postextubation non-invasive ventilation (p = 0.04).The air leak was absent for the duration of mechanical ventilation (i.e., ≥ 30 cm H 2 O at intubation and extubation) in ten patients. Absence of the air leak did not predict extubation failure (negative predictive value, NPV 27%, 95% CI 6% to 60%). The ALT was ≥ 30 cm H 2 O prior to extubation in 47% (28/59) of patients yet 23 patients extubated successfully (NPV 18%).Conclusions: An endotracheal tube air leak pressure ≥ 30 cm H 2 O measured in the non-paralyzed patient prior to extubation or for the duration of mechanical ventilation was common and did not predict an increased risk for extubation failure. Pediatric patients who are clinically identified as candidates for an extubation trial but do not have an endotracheal tube air leak may successfully tolerate removal of the endotracheal tube.

Pediatric upper airway obstruction: Interobserver variability is the road to perdition

“…It may be that our clinical assessment of UAO is less reliable for younger patients, and age may not actually be a risk factor for the development of post-extubation UAO. In our study, the presence of an air leak at extubation was similar regardless of the definition of post extubation UAO, echoing previous investigations 18,19 . Nevertheless, this factor alone is used in clinical decision making for extubation readiness or prophylactic corticosteroids by close to 70% of US pediatric critical care training programs 9 .…”

The Use of Extubation Readiness Parameters: A Survey of Pediatric Critical Care Physicians

“…25 However, when studied, an air leak pressure of Ն 30 cm H 2 O did not predict extubation failure or outcome. 26 The present survey re- flects that most physicians are concerned about postextubation stridor, despite the lack of evidence that air leak predicts extubation success or failure.…”

Evaluating Risk Factors for Pediatric Post-extubation Upper Airway Obstruction Using a Physiology-based Tool

“…Unfortunately, pediatric data identifying risk factors (7)(8)(9)(10)(11)(12)(13) for subglottic post-extubation UAO are limited. Causes of this paucity of data in previous studies include use of imprecise or impractical outcomes or not having differentiated subglottic from supraglottic obstruction.…”