This discussion will deal with two phases of pulmonary emphysema which have to do with the lung as a respiratory organ quite apart from the respiratory threshold, minute-volume of blood passing through the pulmonary circulation and influences from the peripheral nerve supply of the respiratory organs.
Patients who apparently have the same degree of emphysema behave in different ways. One of my patients had pronounced cyanosis, a respiratory rate of 16 to 18 per minute, a minute-volume of respired air of 8 liters. Co2 content of his alveolar air was 8.55 per cent. This patient did not suffer from air hunger and never had an asthmatic attack.
The second patient presented two phases. On admission to the hospital he was cyanotic. The respiratory rate was 14 per minute. The minute-volume of respired air was from 8 to 10 liters. The alveolar air contained 7.2 per cent. of Co
HOOVER CF. THE MINUTE VOLUME AND ALVEOLAR AIR IN PULMONARY EMPHYSEMA. Arch Intern Med (Chic). 1913;XI(1):52-65. doi:10.1001/archinte.1913.00060250059003