Twenty-five patients of ages 39-72 years, with a maximumventilatory capacity (MVVF) of < 35 % of the predicted values,were classified into a respiratory insufficiency (R) and a comparison(C) group according to the clinical progress of thedisease. With the patients in their habitual state, the totalhaemoglobin (THb, g), the pulmonary and systemic pressures,cardiac output (Q, l/min) and pulmonary (PVR) and systemic(SVR) vascular resistance in (mmHg/l). min were measuredat rest and during work.The mean values and S.E.M. in groups R and C were asfollows: for THb 7.4f0.3 and 8.6f0.5 g/kg, blood volume59.1 f 2.0 and 64.9 f2 .8 ml/kg, S ~ O8,6 .2+ 2.2 and 90.4 f 1.4 Yo,avos 48.5f2.5 and 53.2f2.6 ml/l, pulmonary arterial meanpressure 31+ 2 and 26f 2 mmHg, PVR 4.7f 0.5 and 3.2k 0.3(mmHg/l). min, arterial mean pressure 105f4 and 102f4mmHg, SVR 23.1f1.2 and 23.9k1.8 (mmHg/l). min. Qwas 4.5 f 0.2 in the R-group male patients and 4.7f 0.3 I/minin the females, and 4.5f 0.3 in the C-group male patients and3.5 I/min in the one female patient.During work (not performed in all patients of group R) atmean work loads of 160 kpm/min in 4 male patients of groupR, Q was 6.5f 0.5 l/min, at 90 kpm/min in 3 female patients ofgroup R 6.4f0.2 I/min, at 150 kpm/min in 10 male patientsof group C 6.7k 0.4 I/& and at 150 kpmimin in the femalepatient of group C 5.2 I/min. It is emphasized that both theright and
1972. Vol. 77, no 3, 149-162 p.