Time-course of ventilation, arterial and pulmonary CO(2) tension during CO (2) increase in humans.
A change of ventilation (VE), PaCO(                 2               ) (arterial CO(                 2               ) tension) and PvCO(                 2               ) (pulmonary arterial CO(                 2               ) tension) with time was not evaluated precisely during exercise or CO(                 2               ) rebreathing in humans. In this study, changes of these variables with time were fitted to exponential curves {y = Exp ( x/ T + A ) + k} and compared. When exercise pulmonary hemodynamics was examined in 15 cardiac patients to decide therapies, we asked the patients to undergo CO(                 2               ) rebreathing using air with supplementation of consumed O(                 2               ). Arterial and pulmonary blood was drawn every minute. During exercise, T was 28.2 ± 8.4 and 26.8 ± 12.4, and A was 0.80 ± 0.50 and 0.50 ± 0.90 in VE and PvCO(                 2               ), respectively, with no statistical differences. During CO(                 2               ) rebreathing, T was 18.6 ± 5.8, 41.8 ± 38.0 and 21.6 ± 9.7 and A was 0.39 ± 0.67, 1.64 ± 1.35 and 0.17 ± 0.83 in VE, PaCO(                 2               ) and PvCO(                 2               ), respectively, with statistical difference of PaCO(                 2               ) from other variables, suggesting that VE and PvCO(                 2               ) showed same mode of change according to time but PaCO(                 2               ) did not.
Department of Medicine, Kyorin University School of Medicine, Mitakashi, Tokyo, Japan. tsatoh2008@me.com
Toru
T
Satoh
Yasumasa
Y
Okada
Yasushi
Y
Hara
Fumio
F
Sakamaki
Shingo
S
Kyotani
Takeshi
T
Tomita
Noritoshi
N
Nagaya
Norifumi
N
Nakanishi
D000328:Adult; D000368:Aged; D001158:Arteries / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008168:Lung / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012119:Respiration
D002245:Carbon Dioxide