Heating of air in the nasal airways

Background and objective. The purpose of this study was to determine whethe r the temperature at the end of inspiration is the same as the temperature a few seconds after breathing stops at the end of inspiration to study if t he nasal mucosa are capable of providing heat during a cessation of breathi ng. Patients/methods. Fifteen healthy volunteers were included in the study. Th e temperature at the end of inspiration was compared to the temperature obt ained 5 s after cessation of breathing at the end of inspiration and at the end of expiration. Intranasal temperature measurements were taken at three locations in the nose with a miniaturized thermocouple. Results. The temperature increased during cessation of breathing at all loc ations. The highest temperature differences between the end of inspiration and 5 s later (breathing at rest) could be observed at the nasal Valve area . The lowest temperature difference was found in the nasopharynx. At the en d of expiration, the temperature decreased only slightly from the nasophary nx to the nasal Valve area. Conclusions. The anterior part of the nose in particular is capable of heat ing the inspired air. This is also important for humidification. Heating of inspired air requires special anatomical conditions of the anterior nasal segment.