RESPIRATORY CHANGES DURING AN AIRPLANE FLIGHT TO HIGH ALTITUDES

Abstract

By frequently sampling the alveolar air throughout airplane flights, it was shown that the breathing in some men increases in response to the lack of O2 of altitudes as low as 2000-3000 feet; while in others not below 10,000 feet. During flights to 15,000 feet the average alveolar O2 tension fell from 100 to 49.8 mm., the CO2 tension from 40.9 to 29.2 mm. During a stay of 15 minutes at 15,000 feet the breathing continued to increase, with the result that the alveolar O2 tension rose an average of 6.8 mm. The alveolar O2 tension was found to be slightly higher in airplane flights than in mountain climbing or under conditions of simulated altitude. This was attributed to the action of wind. For a while after descent the breathing remained subnormal.