Oxygen cost of voluntary hyperventilation

¹ Department of Medicine, School of Medicine, University of California at Los Angeles, Los Angeles, California

The oxygen cost of voluntary hyperventilation was measured using an open circuit technique with three variations, unaided hyperventilation of air, breathing through an increased dead space and adding carbon dioxide to the inspired air. After a given minute volume had been maintained for 10 minutes, the oxygen consumption was the same with the three methods, in spite of marked differences in the respiratory exchange ratio and volume of carbon dioxide produced. The mean oxygen cost for all three methods was 3.2 ml/l. of ventilation. The amount of nonmetabolic oxygen stored during the first minute of hyperventilation was estimated by finding the difference between the oxygen uptake during the 1st minute and the amount utilized when a steady state is reached. It is concluded that the effects of changing oxygen stores are minimal after 10 minutes of hyperventilation and probably after 5 minutes, at a constant minute volume.

Note:
(With the Technical Assistance of Liana Nebel)