Vasopressin versus norepinephrine infusion in patients with vasoplegic shock after cardiac surgery

Abstract

Introduction: Vasopressin is commonly used as an adjunct to catecholamines to support blood pressure in refractory septic shock. Its effect on vasoplegic shock after cardiac surgery is unknown. We hypothesized that low-dose vasopressin as compared with norepinephrine would decrease the length of stay in the ICU in patients submitted to cardiac surgery with a pump. Methods: We assigned patients who presented vasoplegic shock after cardiac surgery in the first 24 hours after arrival in the ICU. During 6 months, out of 458 patients undergoing cardiac surgery, 82 developed vasoplegia shock and participated in the study. We randomly assigned patients to receive norepinephrine (initial doses of 5 mg) or vasopressin (0.01 to 0.04 U/min). All vasopressor infusions were titrated and tapered according to protocols to maintain a target blood pressure. The primary endpoint was the length of ICU stay. Secondary endpoints were mortality, timing of needing vasopressors, incidence of organ dysfunction and adverse effects. Results: A total of 82 patients were included in the analysis - 42 patients received norepinephrine and 40 patients received vasopressin. There was a significant difference between the norepinephrine and vasopressin groups in the length of ICU stay (4.2 days vs. 7.3 days, P <0.005). Also, the vasopressin group of patients presented a lower incidence of renal failure compared with the norepinephrine group (4.5% vs. 8.9%, P <0.001). There was no significant difference in the overall rates of adverse events, rates of mortality and timing of vasopressor therapy. Conclusions: Low-dose vasopressin reduced the length of ICU stay and the incidence of renal failure in patients with vasoplegic shock after cardiac surgery compared with norepinephrine. Also, a the vasopressin group did not present more adverse events.