Restricted postexercise pulmonary diffusion capacity does not impair maximal transport for O2.
We evaluated whether the postexercise reduction of pulmonary diffusion capacity for carbon monoxide (DLco) is influenced by a second bout of rowing and whether it affects arterial O2 tension during maximal exercise. After exercise, DLco was reduced [from a median of 37 (range of 30-44) to 34 (27-40) ml.min-1.mmHg-1; n = 21; P < 0.001], and both the membrane diffusion capacity [from 80 (58-139) to 68 (54-104) ml.min-1.mmHg-1] and the pulmonary capillary blood volume [from 88 (74-119) to 79 (61-121) ml; P < 0.01] were affected. A second bout of exercise did not influence DLco or membrane diffusion capacity (n = 7), but during both bouts arterial O2 tension was reduced [from 105 (91-110) to 91 (77-102) Torr; P < 0.001] and arterial O2 saturation decreased [from 0.98 (0.97-0.99) to 0.95 (0.86-0.96); P < 0.001]. Furosemide (iv) did not affect DLco (n = 7), suggesting that it was influenced by the central blood volume rather than by pulmonary edema.
Hanel
B
B
Copenhagen Muscle Research Center, Department of Anesthesia, Rigshospitalet, University of Copenhagen, Denmark.
Clifford
P S
PS
Secher
N H
NH
D000328:Adult; D001639:Bicarbonates / Q000097:blood; D001784:Blood Gas Analysis; D001810:Blood Volume; D002248:Carbon Monoxide; D002302:Cardiac Output / Q000187:drug effects; D004562:Electrocardiography; D015444:Exercise / Q000502:physiology*; D005665:Furosemide / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000097:blood; D019344:Lactic Acid; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption; D011652:Pulmonary Circulation; D011653:Pulmonary Diffusing Capacity / Q000187:drug effects / Q000502:physiology*
D001639:Bicarbonates; D007773:Lactates; D019344:Lactic Acid; D005665:Furosemide; D002248:Carbon Monoxide; D010100:Oxygen