title: Pulmonary hemodynamics and gas exchange during exercise in liver cirrhosis.
abstract: We have recently shown that ventilation-perfusion (VA/Q) mismatching at rest in cirrhosis is due to an abnormal pulmonary vascular tone. It has been suggested that in patients with cirrhosis, O2 transfer might become diffusion-limited during exercise. This study examined pulmonary hemodynamics and mechanisms modulating gas exchange during exercise (60 to 70% VO2max) in six patients (41 +/- 5 yr, mean +/- SEM) with cirrhosis but with normal lung function tests. At rest, QT was high (8.4 +/- 0.5 L/min), pulmonary vascular resistance (PVR) was low (0.61 +/- 0.17 mm Hg/L/min), and there was mild to moderate VA/Q mismatching (LogSD Q, 0.79 +/- 0.09; normal range, 0.3 to 0.6). However, hyperventilation (PaCO2, 29 +/- 2 mm Hg) and high QT (thus, high PVO2, 41 +/- 2 mm Hg) contributed to the maintenance of PaO2 within normal values (99 +/- 7 mm Hg). Exercise VO2 (1,278 +/- 122 ml/min) was normal relative to work load, but, contrary to that in normal subjects, QT was higher and PVR did not fall. During exercise, PaO2 showed a trend to decrease (to 90 +/- 5 mm Hg) and PaCO2 to rise (to 35 +/- 2 mm Hg), but the differences failed to reach statistical significance (p = 0.07 each). PVO2 fell significantly with exercise (41 +/- 2 to 33 +/- 0.3 mm Hg, p less than 0.05), but neither AaPO2 (15 +/- 7 to 21 +/- 6 mm Hg) nor VA/Q inequality (LogSD Q, 0.82 +/- 0.11) changed. No systemic difference was noticed between predicted and measured PaO2 values, suggesting no O2 diffusion impairment during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department de Medicina, Hospital Clinic, Barcelona, Spain.
authors.forename: A G
authors.initials: AG
authors.lastname: Agusti
authors.forename: J
authors.initials: J
authors.lastname: Roca
authors.forename: R
authors.initials: R
authors.lastname: Rodriguez-Roisin
authors.forename: R
authors.initials: R
authors.lastname: Mastai
authors.forename: P D
authors.initials: PD
authors.lastname: Wagner
authors.forename: J
authors.initials: J
authors.lastname: Bosch
mesh_terms: D000328:Adult; D015444:Exercise; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008099:Liver / Q000503:physiopathology; D008103:Liver Cirrhosis / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011652:Pulmonary Circulation; D011659:Pulmonary Gas Exchange; D012129:Respiratory Function Tests; D014692:Ventilation-Perfusion Ratio