Airway humidification with a heat and moisture exchanger in mechanically ventilated neonates: A preliminary evaluation

Abstract

Objective: We set out to evaluate the efficacy of passive inspiratory gas conditioning in mechanically ventilated neonates and compared it with that of a heated humidifier (HH). Design: Prospective, randomized, controlled study. Setting: Neonatal and pediatric intensive care unit. Patients: Fourteen mechanically ventilated neonates nursed in incubators. Interventions: The HH was set to deliver a temperature of 37°C and an absolute humidity of 40 mgH2O/l at the incubator entrance. Inspired temperature (T°) and absolute humidity (AH) were measured by the psychometric method, transpulmonary pressure (Tpres) by means of a differential pressure transducer. Measurements were performed at 5, 10, and 15 min. Measurements and results: The values of T° were significantly higher using the HH (34.6 ± 1.6°C) than the heat and moisture exchanger (HME) (33.8 ± 2.3, p < 0.001). The values of AH were significantly higher using the HH (36.6 ± 2.5 mgH 2O/l) than the HME (32.4 ± 2.8 mgH2O/l, p < 0.001). No significant changes were observed in transpulmonary pressure. A significant positive correlation was observed between incubator temperature and the temperature delivered by the HH (R2 = 0.61, p < 0.001). Conclusions: The use of HMEs in neonates made it possible to achieve an absolute humidity of 28 mgH2O/l or more and a temperature of 30°C or more. Higher values are obtained using a HH. © 2006 Springer-Verlag.