DOBUTAMINE ADMINISTRATION IN SEPTIC SHOCK - ADDITION TO A STANDARD PROTOCOL

Dobutamine administration has been shown to increase oxygen delivery in various conditions, but there are little data to document its effects in septic shock. We investigated the effects of dobutamine infusion at a rate of 5 μg/kg·min in 18 patients (mean 60 ± 16 yr) with septic shock initially characterized by hypotension, oliguria, and hyperlactatemia in the presence of a documented source of sepsis. Early resuscitation had consisted of fluid administration and vasopressors when required. When added to this standard regimen, dobutamine had no significant effect on mean arterial pressure (MAP) (from 71 ± 12 to 73 ± 13 mm Hg), but markedly increased cardiac index (from 3.0 ± 0.7 to 3.9 ± 1.0 L/min·m2, p < .001), stroke index (from 32 ± 8 to 37 ± 9 ml/m2, p < .001) and oxygen transport (from 410 ± 105 to 530 ± 146 ml/min·m2, p < .001). Oxygen consumption (V̇O2) increased concurrently (from 137 ± 42 to 162 ± 66 ml/min·m2, p < .002). MAP increased (from 68 ± 9 to 76 ± 11 mm Hg) in 12 patients and decreased moderately (from 76 ± 18 to 69 ± 17 mm Hg) in six patients. The two subgroups of patients had similar hemodynamic profiles before the dobutamine infusion, but vasopressor therapy was already used in one of the 12 patients in the first subgroup and in three of the six patients in the second subgroup (p < .05). The BP decrease in the second subgroup was related to a vascular effect associated with a larger decrease in systemic vascular resistance (-24% vs. -10% in the other patients). A significant decrease in right atrial pressure (from 13.0 ± 4.2 to 10.0 ± 3.8 mm Hg, p < .01) also suggested a decrease in preload. Hence, dobutamine infusion at a dose of 5 μg/kg·min can markedly increase oxygen supply and V̇O2 in septic shock, and is well tolerated.