Respiratory Heat Loss and Pulmonary Function during Cold-Gas Breathing at High Pressures.

摘要

In deep diving, significant heat loss through the lungs--both in warming and in humidifying the inspired cold gas--occurs due to the increased thermal capacity of the breathing-gas mixture. Other factors which increase respiratory heat loss (RHL) are a decrease in inspired gas temperature (T1) and an increase in respiratory minute volume (VE). The purpose of this study was to measure RHL in two divers at rest and at four graded levels of exercise while breathing cold gas at simulated depths to 1000 feet of sea water (fsw). A secondary purpose was to study cardiopulmonary function and to investigate the possibility of pulmonary damage from dense, cold gas acting directly on the respiratory tract mucosa.