[Effect of theophylline on disturbances of ventilation and of gas exchange during exercise in patients with pulmonary emphysema].
Factors limiting exercise were studied in 23 patients with pulmonary emphysema, and the effects of theophylline on exercise tolerance and on hypercapnic ventilatory response were studied in 16 patients with pulmonary emphysema. Exercise in these patients was limited by inability to increase tidal volume and by disturbances of gas exchange, as indicated by low PaO2, high AaDO2, and high PaCO2 during exercise, and by low diffusing capacity. Theophylline increased tidal volume during exercise, but it did not improve oxygenation during exercise. Theophylline improved exercise tolerance and hypercapnic ventilatory response. The percent increases in VEmax and in VO2max after theophylline administration correlated significantly with the percent increase in the ratio of mouth occlusion pressure to PACO2 during rebreathing. These results indicate that exercise tolerance in patients with pulmonary emphysema can be improved by theophylline, probably because of an increase in ventilatory drive.
Senju
S
S
Second Department of Internal, Medicine, School of Medicine, Fukuoka University, Japan.
Toyoshima
H
H
Ikeda
A
A
Aritomi
T
T
Watanabe
K
K
Ishibashi
M
M
Yoshida
M
M
D000368:Aged; D001993:Bronchodilator Agents / Q000627:therapeutic use*; D017079:Exercise Tolerance / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D011656:Pulmonary Emphysema / Q000188:drug therapy* / Q000503:physiopathology; D011659:Pulmonary Gas Exchange / Q000187:drug effects*; D012119:Respiration / Q000187:drug effects*; D013806:Theophylline / Q000627:therapeutic use*
D001993:Bronchodilator Agents; D013806:Theophylline