The cuff leak test prior to extubation: A practice based on limited evidence

Endotracheal intubation and mechanical ventilation are lifesaving interventions that are commonly performed in the intensive care unit (ICU). The trauma of endotracheal intubation itself, the prolongued pressure exerted by the endotracheal tube on the larynx, and miscellaneous factors such as fluid overload can result in laryngeal edema (LE). Extubation of a patient with undiagnosed LE can results in respiratory failure secondary to an upper airway obstruction and may require reintubation. Respiratory failure requiring reintubation is associated with morbidity and mortality. The cuff leak test (CLT) is the only method intensivists use to predict the presence of LE. Despite the CLT's first description in 1988, the correct way to interpret the results (either qualitatively or quantitatively) is unknown, and its diagnostic accuracy has been called into question. In fact, the CLT could be detrimental to patients if it has a high false positive rate (i.e. no air leak is detected indicating LE when none actually exists). Incorrectly diagnosing patients with LE may result in prolongued mechanical ventilation that predisposes patients to barotrauma, ventilator-associated infections, exposure to systemic steroids, and a prolongued stay in the ICU. Given the paucity of data, the Cuff Leak and Airway Obstruction in Mechanically Ventilated ICU Patients (COMIC) research group is conducting a survey to understand international practice surround the use of the CLT prior to extubation, as well as a randomized controlled trial that will capture the accuracy of the test and determine the bet method to measure cuff leak.