Pre-Extubation Cuffed Tube Leak Test and Subsequent Post-Extubation Laryngeal Edema: Prospective, Single-Center Evaluation of PICU Patients*

Abstract

OBJECTIVES: We performed our standard air leak, leak percentage, and cuff leak percentage tests in pediatric patients intubated with microcuff pediatric tracheal tubes (MPTTs) just before extubation. We examined the association between test findings and the subsequent occurrence of post-extubation laryngeal edema (PLE). DESIGN: Prospective, single-center, observational study. SETTING: PICU (June 1, 2020 to May 31, 2021). PATIENTS: Pediatric patients intubated and scheduled for extubation during the day shift in the PICU. INTERVENTIONS: Multiple pre-extubation leak tests were performed on each patient immediately before extubation. In our center, the standard leak test is positive if a leak is audible at 30 cm H2O applied pressure with the MPTT cuff deflated. Two other tests were calculated in the pressure control-assist control ventilator mode using the following formulas: leak percentage with deflated cuff = (inspiratory tidal volume [Vt]–expiratory Vt) × 100/inspiratory Vt; cuff leak percentage = (expiratory Vt with inflated cuff–expiratory Vt with deflated cuff) × 100/expiratory Vt with inflated cuff. MEASUREMENTS AND MAIN RESULTS: The diagnostic criteria for PLE was made by at least two healthcare professionals and included upper airway stricture with stridor-requiring nebulized epinephrine. Eighty-five pediatric patients (< 15 yr) who had been intubated for at least 12 hours using the MPTT were included. Positive rates for the standard leak, leak percentage (cutoff 10%), and cuff leak percentage (cutoff 10%) tests were 0.27, 0.20, and 0.64, respectively. The standard leak, leak percentage, and cuff leak tests showed sensitivities of 0.36, 0.27, and 0.55, respectively; and specificities of 0.74, 0.81, and 0.35, respectively. PLE occurred in 11 of 85 patients (13%), and there were no instances of needing reintubation. CONCLUSIONS: The pre-extubation leak tests in current practice for intubated pediatric patients in the PICU all lack diagnostic accuracy for PLE.