(1557) Optimal Discontinuation Order of Vasopressors in Septic Shock

Introduction: Vasopressin is a vasoactive agent that is frequently added to norepinephrine in patients with septic shock. However, the current guidelines do not make recommendations regarding which vasopressor to discontinue first as the patient improves and shock resolves. Furthermore, there is conflicting data on the incidence of hemodynamic instability based on the sequence of vasopressor discontinuation. Our retrospective study was designed to determine if there is a hemodynamic difference in discontinuing vasopressin first compared to norepinephrine.

Methods: Data was extracted for patients over 18 years of age admitted to the intensive care unit (ICU) who received at least one day of vasopressin and norepinephrine for septic shock. Exclusion criteria included death before vasopressor discontinuation, simultaneous discontinuation of norepinephrine and vasopressin, use of inotropic agents, or identification of other forms of shock. The primary outcome was the incidence of hypotension within 24 hours of vasopressor discontinuation. Secondary outcomes include the number of hypotensive events during the first 24 hours, time until first hypotensive event, incidence of restarting the discontinued vasopressor, ICU length of stay and mortality.

Results: Sixty-four patients were included in the study with no between-group differences noted in the baseline characteristics. Our retrospective analysis reported no significant difference for the primary outcome, with a similar incidence of hypotension within 24 hours of vasopressor discontinuation (45.2% vs. 39.4%, p=0.80). Additionally, while not statistically significant, the likelihood of vasopressor re-initiation was about twice as likely when vasopressin was discontinued first both 24 hours after discontinuation (18.2% vs. 9.7%, p=0.48) and 48 hours following discontinuation (21.2% vs 9.7%, p=0.30). There was no significant difference in ICU length of stay and mortality.

Conclusions: Based on results of this study, discontinuation of norepinephrine before vasopressin showed a trend towards a reduction in recurrent hypotensive events; however, ICU length of stay and mortality were similar. Prospective randomized trials are needed to validate results of this study and to determine if there is a beneficial order of vasopressor discontinuation in septic shock.