Water bubble test to detect malposition of PLMA

Abstract

cartilage. If the PLMA has been folded over, there is no bubbling, nor there is any movement of the air column. Although the methods described by O’Connor et al. [3] to detect gas venting from the drain tube are sensitive, the soap bubble test needs expertise and soap solution may not be easily available in locations outside the operating room, e.g., in wards or in radiology or endoscopy suites where the PLMA has been now made available as a rescue device for emergency airway management outside operating rooms [4]. Further, the consistency of various soap solutions available on the market is highly variable, and if a thinner solution is used or there is minimal leak, the soap bubble may fail to form a membrane over the drain tube and the soap solution may simply dribble into the drain tube. In regard to the “thread test”, discerning the movements of the thread is highly subjective. Based on the bubble test and the suprasternal notch test, we utilize the following tests to assess PLMA positioning (modifi ed from the tests described by O’Connor et al. [5] and Brimacombe [2]).