The effects of dobutamine on hemodynamic and oxygen transport were evaluated in 43 studies on 34 critically ill general (noncardiac) surgical patients. Dobutamine, beginning at a low dose (2.5 μg/kgċmin) significantly increased cardiac index (CI), oxygen delivery (Do2), and oxygen consumption (Vo2), while decreasing mean arterial pressure, pulmonary artery and wedge pressures, and systemic and pulmonary vascular resistances; blood gases, pH, and pulmonary shunt were not significantly changed. These effects were seen in postoperative and septic patients, as well as in patients with normal, low, and high control CI. These responses were poor in terminally ill and hypovolemic patients; however, when the latter were given additional fluids, their responses were markedly improved. The hemodynamic effects of dobutamine are well known, but the Do2 and Vo2 effects, which suggest improved tissue perfusion, have not been appreciated.