Vasopressin or norepinephrine in early hyperdynamic septic shock:: a randomized clinical trial

Objective: To compare the effects of arginine-vasopressin (AVP) and norepinephrine (NE) on hemodynamic variables, organ dysfunction, and adverse events in early hyperdynamic septic shock. Design and setting: Randomized, controlled, open-label trial. Patients and participants: Twenty-three patients with early (12 h) hyperdynamic septic shock in two teaching hospitals. Interventions: AVP (0.04-0.20 U min(-1), n = 13) as a single agent or NE (0.1-2.8 mu g kg(-1) min(-1), n = 10) infusion for 48 h to achieve mean arterial pressure at or above 70 mmHg. Measurements and results: Hemodynamic parameters and Sequential Organ Failure Assessment (SOFA) score were measured. AVP and NE equally increased mean arterial pressure over 48 h, but NE was required in 36% of AVP patients at 48 h. Compared to baseline, AVP increased systemic vascular resistance, decreased exposure to NE, decreased cardiac output by decreasing heart rate, increased creatinine clearance, and improved SOFA score. The PrCO2 - PaCO2 difference remained stable throughout the study. One AVP patient developed acute coronary syndrome with dose-dependent ECG changes. Three patients in both groups died during their ICU stay. Conclusion: In early hyperdynamic septic shock, the administration of high-dose AVP as a single agent fails to increase mean arterial pressure in the first hour but maintains it above 70 mmHg in two-thirds of patients at 48 h. AVP decreases NE exposure, has no effect on the PrCO2 - PaCO2 difference, and improves renal function and SOFA score.