Efficacy and Safety of Vasopressin as First-Line Treatment of Distributive and Hemorrhagic Shock States

Background: Norepinephrine remains the first-line option to manage patients with circulatory shock. Limited evidence exists evaluating noncatecholamine compounds as first-line monotherapy for managing noncardiogenic shock. Objective: To compare vasopressin monotherapy with norepinephrine monotherapy for reversal of distributive and hemorrhagic shock. Methods: This was a retrospective cohort study including adult patients who were diagnosed with hypovolemic or septic shock, received fluids, and received norepinephrine or vasopressin monotherapy for at least 1 hour. Patients excluded lacked a clear diagnosis, were initiated on 2 or more vasopressors at once, or underwent cardiac surgery. The primary outcome was time to shock reversal. Secondary outcomes included mortality, lengths of stay, and safety end points. A multivariable Cox proportional hazards model was performed incorporating baseline and treatment variables. Results: A total of 85 and 160 patients were treated with vasopressin and norepinephrine, respectively. A decrease in time to shock reversal was observed in the vasopressin group (58.32 hours [95% CI, 50.88-66.00] vs 74.64 hours [95% CI, 60.96-88.32], P = 0.004). Mortality was lower in the vasopressin group (25% vs 41%, P = 0.01), and intensive care unit length of stay was longer (13 days [interquartile range, IQR = 7-19] vs 7 days [IQR = 5-9], P = 0.006). Remaining secondary outcomes were similar. The multivariable analysis revealed no difference in time to shock reversal. Conclusion and Relevance: First-line vasopressin exhibited faster time to distributive shock reversal in the unadjusted analysis but failed to maintain this difference in the multivariable analysis. These findings support safe use of vasopressin as first-line therapy or as an alternative to norepinephrine in distributive shock.