Methylene blue is associated with poor outcomes in vasoplegic shock

Abstract

Objectives: The purpose of this study was to investigate whether patients who received methylene blue as treatment for vasoplegia during cardiac surgery with cardiopulmonary bypass had decreased morbidity and mortality.

Design: Retrospective analysis.

Setting: Single tertiary care university hospital.

Participants: Adult patients who suffered from vasoplegia and underwent all types of cardiac surgery with cardiopulmonary bypass at this institution between 2007 and 2008.

Interventions: With IRB approval, the authors reviewed the charts of the identified patients and divided them into 2 groups based on whether they had received methylene blue. Two hundred twenty-six patients were identified who met the inclusion criteria for the study. Fifty-seven of these patients had received methylene blue for vasoplegia. The authors collected data on preoperative and intraoperative variables as well as outcomes.

Measurements and main results: The patients who received methylene blue had higher rates of in-hospital mortality, a compilation of morbidities, as well as renal failure and hyperbilirubinemia. A multiple logistic regression model demonstrated that receiving methylene blue was an independent predictor of in-hospital mortality (p value: 0.007, OR 4.26, 95% CI: 1.49-12.12), compilation of morbidities (p value: 0.001, OR 4.80, 95% CI: 1.85-12.43), and hyperbilirubinemia (p value:<0.001, OR 6.58, 95% CI: 2.91-14.89). Using propensity score matching, the association with morbidity was again seen but the association with mortality was not found.

Conclusions: The current study identified the use of methylene blue as treatment for vasoplegia to be independently associated with poor outcomes. While further studies are required, a thorough risk-benefit analysis should be applied before using methylene blue and, perhaps, it should be relegated to rescue use and not as first-line therapy.

Keywords: cardiac surgery; methylene blue; outcome; vasoplegia; vasoplegic shock.