INFLUENCE OF BREATHING RESISTANCE OF HEAT AND MOISTURE EXCHANGERS ON TRACHEAL CLIMATE AND BREATHING PATTERN IN LARYNGECTOMIZED INDIVIDUALS

Background. The aim of this study was to determine the influence of breathing resistance of heat and moisture exchangers (HMEs) on endotracheal climate and breathing pattern. Methods. Endotracheal temperature and humidity and tidal volumes were measured in 11 laryngectomized patients with a regularly used HME with "standard" breathing resistance (Pro-vox Normal HME; R-HME), a low breathing-resistance HME (Provox HiFlow HME; L-HME), and without HME. Results. Both R-HME and L-HME increased end-inspiratory humidity (+5.8 and 4.7 mgH(2)O/L, respectively), decreased end-inspiratory temperature (-1.6 and -1.0 degrees C, respectively). and prolonged the exhalation breath length to approximately 0.5 seconds. The R-HME significantly enlarged tidal volumes (0.07 L; p < .05). Conclusions. Both HMEs significantly improve tracheal climate. The R-HME has better moistening properties and a small but significant positive effect on tidal volume. Therefore, if the higher resistance is tolerated, the R-HME is the preferred pulmonary rehabilitation device. The L-HME is indicated if lower breathing resistance is required. (C) 2009 Wiley Periodicals, Inc. Head Neck 32: 1069-1078, 2010