Intraoperative or postoperative hydroxocobalamin, which is better for patients receiving cardiopulmonary bypass?

A vasoplegic syndrome is a form of vasodilatory shock following cardiopulmonary bypass that affects up to half of all patients undergoing major cardiovascular surgery.

Hydroxocobalamin inhibits nitric oxide pathways that contribute to vasoplegic shock in patients undergoing cardiopulmonary bypass. Divya A. Khandekar, Department of Pharmacy, Mayo Clinic, Rochester, MN, and colleagues aimed to determine the impact of intraoperative versus postoperative application of hydroxocobalamin for vasoplegic shock in patients receiving cardiopulmonary bypass in a historical cohort study.

In the study, set in a quaternary academic cardiovascular surgery program, 112 patients undergoing cardiac surgery using cardiopulmonary bypass were included. They were allocated to the intervention of hydroxocobalamin 5 grams intravenous over 15 minutes.

The assignment of the treatment groups was bone based on the receipt location of hydroxocobalamin i.e., ICU (intensive care unit) versus operating room (OR). The study's primary outcome was determined as vasopressor-free days in the first 14 days after CPB. Of the 112 included patients, 37 patients received hydroxocobalamin in the OR and 75 in the ICU.

The authors reported the following findings:

• Patients in the OR group were younger than those in the ICU group (57.5 versus 63.9 years), 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.
• The norepinephrine-equivalent dose of vasopressors at hydroxocobalamin was 0.27 mcg/kg/min in both groups.
• Days alive and free of vasopressors were not different between the OR and ICU groups (HR 0.48).
• The odds of postoperative renal failure, mesenteric ischemia, ICU and hospital length of stay, and in-hospital mortality were also similar between groups.

"We did not find a difference in vasopressor-free days after CPB between patients who received hydroxocobalamin intraoperatively versus postoperatively for vasoplegic shock," the researchers concluded.

Reference:

The study titled, "Intraoperative versus postoperative hydroxocobalamin for vasoplegic shock in cardiothoracic surgery," was published in the Journal of Cardiothoracic and Vascular Anesthesia.

DOI: https://doi.org/10.1053/j.jvca.2023.08.145