Methylene Blue: A Look at Its Use in Low Blood Pressure and Circulation Problems

Methylene Blue: Revisited - Applications in Vasoplegia and Hypotension

https://pmc.ncbi.nlm.nih.gov/articles/PMC3087269/

This comprehensive review examines methylene blue's various medical applications, particularly focusing on its role in treating hypotension associated with different clinical states. The authors discuss how methylene blue, an inhibitor of nitric oxide synthase and guanylate cyclase, improves hypoxia and hyperdynamic circulation in conditions such as cirrhosis of the liver and severe hepatopulmonary syndrome, as well as improving blood pressure and cardiac function in septic shock3.

A significant portion of the review addresses methylene blue's efficacy in treating catecholamine-refractory vasoplegia, a condition characterized by profound hypotension despite normal or high cardiac output. The mechanism of action involves inhibiting guanylate cyclase, thereby decreasing cyclic guanosine monophosphate (C-GMP) and preventing excessive vascular smooth muscle relaxation. The article also describes preoperative and intraoperative protocols for methylene blue administration in cardiac surgery settings, highlighting its potential to reduce the incidence and severity of vasoplegic syndrome in high-risk patients3.