LAUSR

Background: Current guidelines recommend norepinephrine as the first-line vasopressor in septic shock followed by addition of vasopressin to achieve a goal mean arterial pressure. Limited evidence exists evaluating how the timing of vasopressin addition affects clinical outcomes in septic shock. Objective: The objective of this study was to determine whether the timing of the addition of vasopressin to norepinephrine affects shock resolution. Methods: This was a multi-site, single system, retrospective cohort, institutional review board (IRB)-approved study examining adult patients with septic shock who received norepinephrine and vasopressin. Patients were divided and statistically analyzed in two subgroups: early vasopressin addition (<3 hours) and late vasopressin addition (≥3 hours). The primary outcome was time to shock resolution, defined as vasopressor free for at least 24 hours. Secondary outcomes included norepinephrine dose at 3 hours after initiation of vasopressin, in-hospital mortality, and intensive care unit length of stay. Results: A total of 243 patients were included in this study. A statistically significant decrease in time to shock resolution was observed in the early vasopressin addition group compared to the late vasopressin addition group (37.6 hours vs 60.7 hours; adjusted hazard ratio [HR]: 2.07 [1.48-2.89; P = <0.001]). The early addition of vasopressin did not affect norepinephrine dose or in-hospital mortality but did lead to a decreased intensive care unit (ICU) length of stay (4.3 days vs 5.3 days, P = 0.02). Conclusion and Relevance: Addition of vasopressin to norepinephrine within 3 hours was associated with a faster time to shock resolution. These findings suggest a potential for improved clinical outcomes with earlier vasopressin addition.