ABSTRACT
The term vasoplegia describes hypotension refractory to vasopressor therapy, a common finding related to cardiac surgery requiring cardiopulmonary bypass. High doses of vasoactive agents are associated with adverse effects such as peripheral and mesenteric ischemia. Databases were systematically searched for literature on methylene blue as an adjunct therapy to treat vasoplegia. Fifteen articles were selected. The quality of the studies was evaluated using the US Preventive Services Task Force (USPSTF) grading tool, and a chart was created to present the components of each study. Preoperative, intraoperative, and postoperative administration of methylene blue has been shown to increase systemic vascular resistance and mean arterial pressure, with the period after surgery being the most common time for use of this therapy. Decreased vasopressor requirements have also been consistently demonstrated after methylene blue administration. This catecholamine-sparing effect prevents vasopressor-related injury. Its favorable safety profile as well as hemodynamic effects have made methylene blue a valuable adjunct in the setting of vasoplegia. Methylene blue is an effective treatment of refractory hypotension related to cardiac surgery requiring cardiopulmonary bypass. Larger, randomized controlled trials are needed to strengthen the state of the evidence and to define specific doses.
