Endotracheal Tube Cuff Inflation Methods in School-Age Children: Flow-Volume Loop-Guided Versus Stethoscope-Guided

Abstract

Background: In pediatric patients, the intracuff pressure of endotracheal tubes should be as low as possible to prevent injury to the tracheal mucosal wall. The conventional stethoscope-guided technique relies solely on the operator's sensitivity of audible detection, which may lead to increased intracuff pressure. This study was conducted to compare the flow-volume loop guided technique for endotracheal tube cuff inflation with the stethoscope-guided technique and to determine whether the flow-volume loop guided technique results in lower and more consistent intracuff pressure. Methods: The participants were randomized to undergo either the flow-volume loop guided or the stethoscope-guided cuff inflation technique. In the flow-volume loop guided group, the cuff was inflated until the flow-volume loop was completely sealed. In the stethoscope-guided group, the cuff was inflated until the leakage was not audible. Cuff inflation was performed twice with incremental volumes of 0.5 mL and 0.2 mL to determine the consistency of the methods. The primary outcome was the intracuff pressure, and the secondary outcome was the incidence of postextubation complications. Results: Eighty participants (4 to 12 years old) were included in this study. The use of the flow-volume loop guided technique was associated with a lower cuff pressure versus use of the stethoscope-guided technique when inflated at the 0.5-mL increment [14 (6-18) cm H2O vs 19 (9-24) cm H2O; P < .001] and at the 0.2-mL increment [14 (6-18) cm H2O vs 18 (9-24) cm H2O; P < .001], with better consistency between the measured cuff pressures (z = -2.299; P = .02). The presence of postextubation complications (6/80) was not significantly different between the 2 groups but was associated with the American Society of Anesthesiologists physical status (P < .001). Conclusions: The flow-volume loop guided technique for endotracheal tube cuff inflation is a more objective technique that effectively seals the airway with the lower cuff pressure to allow for mechanical ventilation in pediatric subjects during anesthesia.