Intraoperative Versus Postoperative Hydroxocobalamin for Vasoplegic Shock in Cardiothoracic Surgery

Abstract

Hydroxocobalamin inhibits nitric oxide pathways contributing to vasoplegic shock in patients undergoing cardiopulmonary bypass (CPB). The objective of this study was to evaluate the effect of intraoperative versus postoperative application of hydroxocobalamin for vasoplegic shock in patients undergoing CPB. This was a historic cohort study. The study was conducted at a quaternary academic cardiovascular surgery program. Adults undergoing cardiac surgery using CPB were participants in the study. Hydroxocobalamin (5 g) intravenously over 15 minutes. The treatment groups were assigned based on the receipt location of hydroxocobalamin (ie, intensive care unit [ICU] versus operating room [OR]). The primary outcome was vasopressor-free days in the first 14 days after CPB. Of the 112 patients included, 37 patients received hydroxocobalamin in the OR and 75 in the ICU. Patients in the OR group were younger than those in the ICU group (57.5 v 63.9 years, p=0.007), with statistically similar American Society of Anesthesiologists scores. The mean CPB duration was 3.4 hours in the OR group and 2.9 hours in the ICU group (p=0.09). In both groups, the norepinephrine-equivalent dose of vasopressors at hydroxocobalamin was 0.27 µg/kg/min. Days alive and free of vasopressors were not different between the OR and ICU groups (hazard ratio 0.48 [95% CI 1.76-2.72], p=0.67). The odds of postoperative renal failure, mesenteric ischemia, ICU, hospital length of stay, and in-hospital mortality were also similar between groups. A difference in vasopressor-free days after CPB was not found between patients who received hydroxocobalamin intraoperatively versus postoperatively for vasoplegic shock.