Methylene Blue for Vasoplegic Syndrome

Vasoplegic syndrome is a form of vasodilatory shock that occurs frequently in patients who undergo cardiac surgery requiring cardiopulmonary bypass (CBP). Treatment often demands high doses of vasopressors over sustained periods for hypotension that can be refractory to standard vasoactive medications. Furthermore, the development of vasoplegia greatly contributes to morbidity and mortality following cardiac surgery. Methylene blue (MB) has become a popular therapy for cardiac vasoplegia despite a paucity of prospective data to direct its use. Therefore, the aim of this study was to review available data regarding mechanisms, dosing strategies, and side effects of MB, with a focus on its applications for vasoplegia in cardiac surgery.