Effect of dobutamine on pulmonary gas exchange in patients with severe heart failure.

Abstract

Twenty patients (two female, 18 male, mean age 57 +/- 11 years) with severe heart failure NYHA IV (7 coronary artery disease, 13 congestive cardiomyopathy) were treated with 8.8 +/- 1.7 micrograms.kg-1 x min-1 of dobutamine. Pulmonary gas exchange was analysed by withdrawal of blood samples from a central venous catheter and a radial artery cannula. Dobutamine increased SvO2 from 58.7 +/- 11.2% to 72.2 +/- 6.3% (P = 0.0001) and decreased avDO2 from 7.7 +/- 2.45 Vol% to 4.97 +/- 1.34 Vol% (P = 0.0001). PaO2 and PaCO2 were not changed. Qs/Qt increased slightly from 9.1 +/- 8.3% to 11.3 +/- 6.4% (P = 0.035). Cardiac index increased by 51% (P = 0.0001), pulmonary capillary wedge pressure decreased by 28% (P = 0.0001). In patients with severe heart failure, dobutamine improved haemodynamics without detrimental effects on arterial oxygen concentration.