Extended Duration Infusion of Hydroxocobalamin for Vasoplegic Rescue in Septic Shock.

Nitric oxide (NO) is a gaseous signaling molecule and a key endogenous mediator of vascular tone. Hydroxocobalamin (HCB) affects NO-mediated vasoplegia as (1) a direct inhibitor of nitric oxide synthase (NOS), thereby decreasing its production, and (2) by binding directly to NO and acting as a scavenger. HCB has been increasingly used in the treatment of refractory vasoplegia, particularly in cardiac surgery and liver transplant patients. Sepsis and septic shock are characterized by an increase in inducible NOS expression and activity with excessive NO production, resulting in endothelial dysfunction and profound systemic vasodilation. Therefore, a careful sustained reduction in NO burden represents a potential therapeutic target. Here, we present a case of refractory septic shock, which resolved after an extended duration infusion of high-dose HCB. We hope to foster further exploration regarding the safety, dosing, and efficacy of HCB when administered for vasopressor refractory septic shock.