Vasopressin in vasoplegic shock: A systematic review

BACKGROUND: Vasoplegic shock is a challenging complication of cardiac surgery and is often resistant to conventional therapies for shock. Norepinephrine and epinephrine are standards of care for vasoplegic shock, but vasopressin has increasingly been used as a primary pressor in vasoplegic shock because of its unique pharmacology and lack of inotropic activity. It remains unclear whether vasopressin has distinct benefits over standard of care for patients with vasoplegic shock. AIM: To summarize the available literature evaluating vasopressin vs non-vasopressin alternatives on the clinical and patient-centered outcomes of vasoplegic shock in adult intensive care unit (ICU) patients. METHODS: This was a systematic review of vasopressin in adults (≥ 18 years) with vasoplegic shock after cardiac surgery. Randomized controlled trials, prospective cohorts, and retrospective cohorts comparing vasopressin to norepinephrine, epinephrine, methylene blue, hydroxocobalamin, or other pressors were included. The primary outcomes of interest were 30-d mortality, atrial/ventricular arrhythmias, stroke, ICU length of stay, duration of vasopressor therapy, incidence of acute kidney injury stage II-III, and mechanical ventilation for greater than 48 h. RESULTS: A total of 1161 studies were screened for inclusion with 3 meeting inclusion criteria with a total of 708 patients. Two studies were randomized controlled trials and one was a retrospective cohort study. Primary outcomes of 30-d mortality, stroke, ventricular arrhythmias, and duration of mechanical ventilation were similar between groups. Conflicting results were observed for acute kidney injury stage II-III, atrial arrhythmias, duration of vasopressors, and ICU length of stay with higher certainty of evidence in favor of vasopressin serving a protective role for these outcomes. CONCLUSION: Vasopressin was not found to be superior to alternative pressor therapy for any of the included outcomes. Results are limited by mixed methodologies, small overall sample size, and heterogenous populations.