Evaluating the Impact of a Standardized Protocol for Managing Refractory Vasoplegia After Cardiopulmonary Bypass

This study aimed to evaluate the hemodynamic impact and cost-effectiveness of a standardized protocol for refractory vasoplegia occurring after cardiopulmonary bypass (CPB).

Observational, pre-post study.

A single-center, academic teaching hospital.

Cardiothoracic surgery patients requiring CPB who received at least a single rescue agent (angiotensin II, hydroxocobalamin [a form of vitamin B12], or methylene blue [MB]) perioperatively for refractory vasoplegia.

Refractory vasoplegia was defined as at least 0.25 μg/kg/min norepinephrine equivalents (NEeq), and a stepwise treatment protocol was developed, escalating from MB to angiotensin II and hydroxocobalamin. Patients undergoing CPB after protocol implementation were compared with patients undergoing CPB before protocol implementation, who received rescue agents at the discretion of the managing provider.

The study included 215 patients, with 119 and 96 patients in the pre- and post-protocol groups, respectively. There was no difference in mean NEeq requirement preceding rescue agent administration (0.32 μg/kg/min v 0.31 μg/kg/min). Post-protocol patients experienced a steeper rate of decline in percentage change in NEeq in the initial 3 hours (-2.01% NEeq per 15-minute interval, p < 0.01) and an average cost reduction in vasoactive agents of 30% (p < 0.01) and 26% (p < 0.01) at 24 and 48 hours, respectively. No differences in short-term clinical outcomes were observed between groups.

Implementation of a stepwise protocol using MB, angiotensin II, and hydroxocobalamin for refractory vasoplegia resulted in significant cost savings, hastened NEeq reduction, and similar short-term clinical outcomes.