Benchtop study of leakages across the Portex, TaperGuard and Microcuff Endotracheal tubes under simulated clinical conditions

Objectives: To compare three endotracheal tubes for leakage across the cuff (microaspiration) under a comprehensive set of simulated clinical situations.These were the Mallinckrodt TaperGuard (Covidien, US) with a tapered polyvinyl chloride cuff; the KimVent Microcuff (Kimberly-Clark Health Care, US) with a cylindrical polyurethane cuff; and a conventional Portex (Smiths Medical International Ltd, UK) with a globular polyvinyl chloride cuff. Design: A benchtop experimental study.Setting and materials: A silicone cylinder serving as the model trachea was intubated with each of the three endotracheal tubes, one at a time.A total of 20 mL of water were added above the cuff and leakage measured every minute for 20 minutes under five simulated mechanical ventilation scenarios, including different positive end-expiratory pressure levels, and disconnection with and without spontaneous breathing efforts.Each scenario was studied under three cuff pressures of 10, 20 and 30 cm H 2 O, and then repeated with the application of a continuous suction force of 200 cm H 2 O, and leakage measured every minute for 3 minutes.Results: The outcome of interest was the cumulative amount of leakage.The Microcuff Benchtop study of leakages across the Portex, TaperGuard, and Microcuff endotracheal tubes under simulated clinical conditions New knowledge added by this study • Microcuff endotracheal tubes (ETTs) with an ultrathin polyurethane cylindrical cuff provided the best protection against microaspiration under diverse situations.• TaperGuard ETT with a tapered polyvinyl chloride (PVC) cuff provided protection against microaspiration in simulated at-risk situations, given that the cuff pressure was maintained at the recommended 20 to 30 cm of H 2 O.• The most widely used Portex ETT with a globular PVC cuff did not protect against microaspiration under these at-risk simulated situations, even at recommended cuff pressures of 20 to 30 cm H 2 O. Implications for clinical practice or policy • This study supports more widespread use of ETTs with an ultrathin polyurethane cuff (eg the Microcuff ) to better prevent microaspiration, which is one of the major mechanisms of ventilator-associated pneumonia.• Some scenarios appear more prone to microaspirations, eg zero positive end-expiratory pressure, total disconnection, and spontaneous breathing.The Microcuff ETT outperformed other ETTs, particularly in such scenarios.