Oxygen breathing and ventilation.
We investigated the ventilatory response to normobaric poikilocapnic hyperoxia in healthy subjects. The study was carried out in 26 subjects of the mean age 26 +/- 0.9 (SE) years, who breathed pure oxygen through a two-way valve for 10 min. The subjects were in the sitting position with a mouthpiece and nose clip attached. Ventilatory flow was recorded using a pneumotachograph and minute ventilation was calculated from the tidal and frequency components. The SaO(2) and alveolar CO(2) tension were continuously monitored. Ten of the same subjects constituted a control group in which room air was substituted for oxygen and the tests repeated in the same way at another occasion. We found that oxygen breathing caused a transient 8.4% decline in ventilation, whose nadir was 1 min after the introduction of oxygen. Thereafter, ventilation increased significantly above the baseline value and showed a further rising tendency toward the end of the test. We conclude that acute oxygen treatment is unlikely to have a major inhibitory effect on the carotid body-dependent ventilatory drive in normal subjects. The determinants of the hyperoxic ventilatory stimulation remain to be established in further studies.
Marczak
M
M
Department of Respiratory Research, Medical Research Center, Polish Academy of Sciences, Warsaw, Poland. mpokorski@cmdik.pan.pl
Pokorski
M
M
D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D018496:Hyperoxia / Q000378:metabolism; D008297:Male; D010092:Oximetry / Q000379:methods; D010100:Oxygen / Q000008:administration & dosage* / Q000097:blood / Q000737:chemistry; D010101:Oxygen Consumption; D012123:Pulmonary Ventilation / Q000502:physiology*; D012119:Respiration; D013990:Tidal Volume / Q000502:physiology
D010100:Oxygen