Methylene blue for postcardiopulmonary bypass vasoplegic syndrome: A cohort study

• Authors: Michael Mazzeffi, University of Maryland; Benjamin Hammer, Childrens National Medical Center; Edward Chen, Emory University; Mark Caridi-Scheible, Emory University; James Ramsay, University of California, San Francisco; Christopher Paciullo, Emory University
• Journal Title: Annals of Cardiac Anaesthesia
• Volume: Volume 20, Number 2
• Publisher: Medknow Publications | 2017-04-06, Pages 178-181
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.4103/aca.ACA_237_16
• Subjects: Health Sciences, Medicine and Surgery; Health Sciences, Pharmacy
• Keywords: Cardiac surgery; methylene blue; vasoplegia

Abstract

Background: Methylene blue (MB) has been used to treat refractory hypotension in a variety of settings. Aims: We sought to determine whether MB improved blood pressure in postcardiopulmonary bypass (CPB) vasoplegic syndrome (VS) in a complex cardiac surgery population. Furthermore, to determine variables that predicted response to MB. Setting and Design: This was conducted in a tertiary care medical center; this study was a retrospective cohort study. Materials and Methods: Adult cardiac surgery patients who received MB for post-CPB VS over a 2-year period were studied. Mean arterial blood pressure (MAP) and vasopressor doses were compared before and after MB, and logistic regression was used to model which variables predicted response. Results: Eighty-eight patients received MB for post-CPB VS during the study period. MB administration was associated with an 8 mmHg increase in MAP (P = 0.004), and peak response occurred at 2 h. Variables that were associated with a positive drug response were deep hypothermic circulatory arrest during surgery and higher MAP at the time of drug administration (P = 0.006 and 0.02). A positive response had no correlation with in-hospital mortality (P = 0.09). Conclusions: MB modestly increases MAP in cardiac surgery patients with VS. Higher MAP at the time of drug administration and surgery with deep hypothermic circulatory arrest predict a greater drug response.