The influence of a heat and moisture exchanger on tracheal climate in a cold environment

OBJECTIVE: The incidence of pulmonary complaints, severe tracheitis and lung function deterioration is increased during wintertime in laryngectomized individuals. We analyzed how a heat and moisture exchanger (HME) performs in cold and dry ambient circumstances, and how its efficiency in this environmental climate might be improved. STUDY DESIGN: Randomized crossover. METHODS: Intra-tracheal temperature and humidity were measured in 10 laryngectomized patients with and without HME, in a cold (mean, 4.7 degrees C) and dry (mean, 4.5 mgH2O/L) room. RESULTS: Presence of an HME causes the intra-tracheal mean humidity minima and maxima to increase with 4.2 mgH2O/L (95%CI: 3.3-5.0 mgH2O/L; p <0.001) and 2.4 mgH2O/L (95%CI: 1.7-3.1 mgH2O/L; p <0.001), respectively. The intra-tracheal mean temperature minima and maxima increased with 3.9 degrees C (95%CI: 2.7-5.1 degrees C; p <0.001) and 1.2 degrees C (95%CI: 0.8-1.2 degrees C; p