Humidity

Abstract

Humidification of inspired gases facilitates alveolar gas exchange, ensures function of the mucociliary clearance system, reduces heat loss, and reduces the resistance to airflow in the airways. The nose warms inspired air to at least 34°C, raises the water vapour pressure to at least 90% of the saturated vapour pressure, and filters the air. HMEs are as effective as heated humidifiers in routine use in ITU but heated humidifiers should be considered for sicker patients. Only sterile, distilled water should be used to prevent the transmission of infection and the effect of endotoxins.