The Science Journal of the American Association for Respiratory Care

2011 OPEN FORUM Abstracts


Mark S. Siobal, Gregory Burns, Roberto Bautista; Anesthesia, SFGH/UCSF, San Francisco, CA

Background: The subglottic purge maneuver (SPM) is a method of clearing secretions pooled above the endotracheal tube (ETT) cuff. Various methods for performing this maneuver have been described. ETT cuffs are made with polyvinylchloride (PVC) or thin walled polyurethane (PU), and can have a barrel or tapered shape. This study was done to determine if ETTs with different cuff designs affect the efficiency of the SPM performed at varying levels of CPAP. Method: ETTs of size 7.5 with a standard barrel shaped PVC cuff (Mallinckrodt, HiLo), a tapered PU cuff (Mallinckrodt, Seal Guard), and a barrel shaped PU cuff (Kimberly Clark, Microcuff) were tested. A trachea model positioned at a 30-degree angle with a collection chamber attached at the end was connected to a spring loaded test lung with the compliance set to 40 mL/cm H20. The trachea was intubated with the ETT and the cuff was inflated with 10 mL of air. The trachea was filled with 15 mL of colored water above the cuff. The ETT was attached to Drager XL ventilator in the CPAP mode, Slope 0, Flow Trigger 3L/min, with the Vt limit set to 2.0 L. CPAP levels of 5, 7, 10, and 15 cm H20 were tested. At each CPAP setting the ETT cuff was rapidly deflated for approximately one second and reinflated. Fluid leakage around the deflated cuff was captured in the collection chamber and measured using a gravimetric method. Five measurements at each CPAP level for all ETTs were performed. The highest and lowest measurements were discarded and the remainding three were average. Results: Fluid leakage during the maneuver decreased as CPAP level increased. There was no leakage when CPAP was set to 15 cm H20 for all ETTs tested. Conclusion: In this invitro lung model, cuff design did not impact the effectiveness of a simulated SPM at varying levels of CPAP using the Draeger XL ventilator. Sponsored Research - None