Epinephrine as an inotropic agent in septic shock: A dose-profile analysis

OBJECTIVETo characterize the acute actions and physiologic dose profile of epinephrine, as a single inotrope, in patients with septic shock. DESIGNProspective clinical study. The relationship between epinephrine dose and cardiovascular variables was analyzed using repeated-measures analysis of variance. SETTINGICU in a university teaching hospital. PATIENTSEighteen patients with septic shock, mean age 64 ± 8 (SD) yrs, and with a mean admission Acute Physiology and Chronic Health Evaluation (APACHE II) score of 23 (range 14 to 35). INTERVENTIONSInitial volume loading and the measurement of a baseline hemodynamic profile were followed by the administration of an epinephrine infusion at 3 μg/min with subsequent increments of 3 μg/min and the determination of a hemodynamic profile after each dose increment. Therapy was titrated to clinical goals of perfusion and restoration of premorbid systolic arterial BP. MEASUREMENTS AND MAIN RESULTSAfter volume loading, mean hemodynamic indices were as followsmean arterial pressure (MAP) 62 ± 7 mm Hg; cardiac index 3.8 ± 1.1 L/min/m; left ventricular stroke work index 25 ± 11 g.m/m; oxygen delivery (Do2) index 460 ± 168 mL/min/m; and oxygen consumption (Vo2) index 165 ± 64 mL/ min/m. In the dose range of 3 to 18 μg/min, epinephrine produced linear increases in average heart rate, MAP, cardiac index, left ventricular stroke work index, stroke volume index, Vo2, and Do2. No effect was noted on pulmonary artery occlusion pressure (PAOP), mean pulmonary arterial pressure, or systemic vascular resistance index. CONCLUSIONSEpinephrine increases Do2 in septic shock by increasing cardiac index without an effect on systemic vascular resistance index or PAOP. (Crit Care Med 1993; 21:70–77)