Adaptation to Anoxia in Chronic Pulmonary Emphysema

FOR MANY years there has been an intense interest in the adaptation of human beings to residence at high altitude. Numerous studies have been made of permanent residents of a mining district in Peru, where the altitude is 10,000 to 15,000 ft. (3,048 to 4,572 meters) above sea level. Residents of high altitude usually exhibit an increase in the hemoglobin content of the blood.1Moreover, with increasing altitude, and hence increasing anoxia, the elevation of the hemoglobin content of the blood becomes more marked. Anoxia also causes an increase in ventilation, with a resultant decline of the carbon dioxide tension in the alveoli and arterial blood.2The lowered carbon dioxide tension in the blood is compensated for by a decrease in bicarbonate, so that the blood pH remains normal.3There has been some disagreement on the effect of high altitude on cardiac output, but apparently the changes