Vasoplegia and cardiopulmonary bypass: role of oxidation-reduction dysregulation as a mechanism and therapeutic target.

Vasoplegia is a leading cause of morbidity and mortality after cardiopulmonary bypass. Current treatments are not improving outcomes. Use of hydroxocobalamin (vitamin B-12) is a novel approach to increase perfusion pressure. Zakaria and colleagues demonstrate its efficacy, although it is not universal. The mechanisms by which vitamin B-12 works merit understanding and investigation. Vitamin B-12 is an antioxidant that protects proteins, DNA, and lipids from attack by the unpaired electrons of free radicals. The observations that vitamin B-12 and other antioxidants, including ascorbic acid and methylene blue, all partially treat vasoplegia should signal to cardiac teams that focused research on the effects of oxidation-reduction dysregulation by inflammation needs further exploration.