Alveolar gas exchanges during breath-hold dives.

Publisher Website
Google Scholar
Abstract
Five experienced divers performed unassisted breath-hold dives to depths ranging from 2. 5 to 10. 0 m. During these 30-sec. dives the V02 [O2 consumption rate] leaving the alveoli varied with the depth of the dive, but the Vco2 [ CO2 consumption rate] entering the alveoli was constant and equaled that of a breath hold at the surface. Changes in Paco2 [alveolar carbon dioxide tension]and Pao2 [alveolar oxygen tension] were observed during the course of unassisted dives to 5 and to 10 m. Similar studies were made during 10-m dives in which the subjects made the descent holding 14-kg lead weights and were pulled up. During breath holds on land and during the 5-m dive, the Paco2, increased throughout the period of apnea. At the deeper depths the Paco2 increased during the descent, but there was no further change while the subject was on the bottom. The Paco2 ranged between 54 and 62 mm Hg. In 1 subject making 3 dives to 15 m (14 sec.) and 3 dives to 20 m (18 sec.) Paco2''s were 79 and 84 mm Hg, respectively, when he arrived on the bottom. Pao2 decreased linearly during the bottom time in all the dives studied. These changes in gas composition suggest that CO2 does not leave the tissues when the diver is at depth.

This publication has 4 references indexed in Scilit: