Immediate Effects of Inhalation of 100% Oxygen at One Atmosphere on Ventilation Volume, Carbon Dioxide Output, Oxygen Consumption and Respiratory Rate in Man

¹ From the Department of Physiology, College of Medicine, The Ohio State University, Columbus, Ohio

Immediate effects of inhalation of 100% oxygen at one atmosphere on respiration in man were studied. Average increases of 6.4, 6.5 and 11.5%, respectively, were obtained in ventilation volume, carbon dioxide output and respiratory rate when the subjects breathed 100% oxygen; with subsequent decreases of 10.5, 11.2 and 7.5%, respectively, occurring on transfer back to outdoor air. These effects were attributed to a partial loss of the ‘dual function’ of hemoglobin. Increased ventilation and carbon dioxide output while breathing 100% oxygen was attributed to stimulation of the medullary respiratory center by increased carbon dioxide tension and increased hydrogen ion concentration; decreased ventilation and retention of carbon dioxide resulted on return to outdoor air from a decreased carbon dioxide tension and hydrogen ion concentration. An increase in respiratory quotient of 42.1% and a decrease in oxygen consumption of 25.8% in breathing outdoor air after oxygen as compared to outdoor air before oxygen indicated a storage on oxygen in the body fluids during the 10 minutes of respiration on 100% oxygen. Control experiments with outdoor air demonstrated successive mean increases in all factors evaluated.