Vasopressin Associated With an Increase in Return of Spontaneous Circulation in Acidotic Cardiopulmonary Arrest Patients

Background: During respiratory and metabolic acidosis, the vasoconstrictive effects of epinephrine may be blunted, whereas the response to vasopressin remains unchanged. The impact of this effect during advanced cardiac life support (ACLS) remains unclear. Objective: Determine if vasopressin therapy in combination with epinephrine was associated with improved outcomes in patients with cardiac arrest compared to epinephrine alone. The primary outcome was difference in rate of return of spontaneous circulation (ROSC). Secondary outcomes included evaluation of rates of ROSC for patients with an initial pH <7.2 and by initial pulseless rhythm. Methods: Single-center, retrospective review conducted from July 2010 to July 2012. Patients >= 18 years of age with documented cardiac arrest requiring ACLS and vasopressor therapy were included. Results: A total of 101 patients met inclusion criteria. There was no difference in rate of ROSC (56% vs 60%, P = 0.68) or survival to hospital discharge (9% vs 5%, P = 0.46) between patients who received vasopressin in combination with epinephrine (n = 43) compared to epinephrine alone (n = 58). Subgroup analysis of ROSC in patients with an arterial pH of <7.2 (n = 35) showed an increased rate of ROSC (63% vs 37%, P = 0.01) in the vasopressin plus epinephrine group versus the epinephrine alone group, respectively. Subgroup analysis by initial cardiac rhythm showed no difference in rate of ROSC. Conclusions: Vasopressin in combination with epinephrine demonstrated improved ROSC in cardiac arrest patients with initial arterial pH <7.2 compared with epinephrine alone, without improving survival to hospital discharge.