Evaluation of the Ability of the Nasal Cavity to Warm and Humidify Inspired Air ^|^mdash;Based on Moisture Recovery Rate^|^mdash;

Abstract

There is no easy method to evaluate the ability of the nose to warm and humidify inspired air, although it is one of the most important functions of the nasal cavity. It is necessary to insert a sensor into the narrow nasal cavity in order to evaluate the ability to warm and humidify, but this procedure is difficult in outpatient care. It has been shown in several previous investigations that even if the cold, dry ambient air goes into the nostrils, air temperature and relative humidity in the nasopharynx will be about °C and nearly %, respectively. Generally, the ability to warm and humidify inhaled air in the oral cavity is lower than that in the nasal cavity. We focused our attention on expiration instead of inspiration. We defined the moisture recovery rate as the ratio of the absolute humidity of expired air and alveolar air. g/m .