Methylene Blue: Magic Bullet for Vasoplegia?

Methylene blue (MB) has received much attention in the perioperative and critical care literature because of its ability to antagonize the profound vasodilation seen in distributive (also referred to as vasodilatory or vasoplegic) shock states. This review will discuss the pharmacologic properties of MB and review the critical care, liver transplantation, and cardiac anesthesia literature with respect to the efficacy and safety of MB for the treatment of shock. Although improved blood pressure has consistently been demonstrated with the use of MB in small trials and case reports, better oxygen delivery or decreased mortality with MB use has not been demonstrated. Large randomized controlled trials are still necessary to identify the role of MB in hemodynamic resuscitation of the critically ill.