Central Haemodynamics at Rest and during Exercise in Severe Chronic Obstructive Lung Disease

Abstract

Twenty-five patients of ages 39–72 years, with a maximum ventilatory capacity (MVV_F) of ≤35% of the predicted values, were classified into a respiratory insufficiency (R) and a comparison (C) group according to the clinical progress of the disease. With the patients in their habitual state, the total haemoglobin (THb, g), the pulmonary and systemic pressures, cardiac output (Q, 1/min) and pulmonary (PVR) and systemic (SVR) vascular resistance in (mmHg/1)ċmin were measured at rest and during work.

The mean values and S.E.M. in groups R and C were as follows: for THb 7.4±0.3 and 8.6±0.5 g/kg, blood volume 59.1±2.0 and 64.9±2.8 ml/kg, S_aO2 86.2±2.2 and 90.4±1.4%, a_O2 48.5±2.5 and 53.2±2.6 ml/l, pulmonary arterial mean pressure 31±2 and 26±2 mmHg, PVR 4.7±0.5 and 3.2±0.3 (mmHg/l) ċ min, arterial mean pressure 105±4 and 102±4 mmHg, SVR 23.1±1.2 and 23.9±1.8 (mmHg/l) ċ min. Q was 4.5 ± 0.2 in the R-group male patients and 4.7 ± 0.3 l/min in the females, and 4.5 ± 0.3 in the C-group male patients and 3.5 l/min in the one female patient.

During work (not performed in all patients of group R) at mean work loads of 160 kpm/min in 4 male patients of group R, Q was 6.5 ± 0.5 l/min, at 90 kpm/min in 3 female patients of group R 6.4 ± 0.2 l/min, at 150 kpm/min in 10 male patients of group C 6.7 + 0.4 l/min and at 150 kpm/min in the female patient of group C 5.2 l/min. It is emphasized that both the right and left ventricular function may be impaired in these patients.