Carbon Dioxide and Respiratory Regulation at Altiude

Abstract

14 young men exposed to a simulated altitude of 22,000 ft. breathed gas mixtures with varying concns. of CO2- The partial pressures of O2 and CO2 in alveolar air were correlated with pulmonary ventilation measurements. The results indicated that hypoxic and CO2 stimuli act independently to produce changes in pulmonary ventilation at altitude. When both are strong they act additively. When however the alveolar partial pressure of CO2 falls below a certain level as a consequence of an increased alveolar ventilation, the level of that ventilation would seem to depend solely on the strength of hypoxic stimuli.