Early Use of Methylene Blue in Vasoplegic Syndrome: A 10-Year Propensity Score-Matched Cohort Study

Abstract

Background: Vasoplegic syndrome is associated with increased morbidity and mortality in patients undergoing cardiac surgery. This retrospective, single-center study aimed to evaluate the effect of early use of methylene blue (MB) on hemodynamics after an intraoperative diagnosis of vasoplegic syndrome (VS). Methods: Over a 10-year period, all patients diagnosed with intraoperative VS (hypotension despite treatment with norepinephrine ≥0.3 μg/kg/min and vasopressin ≥1 IE/h) while undergoing heart surgery and cardiopulmonary bypass were identified, and their data were examined. The intervention group received MB (2 mg/kg intravenous) within 15 min after the diagnosis of vasoplegia, while the control group received standard therapy. The two groups were matched using propensity scores. Results: Of the 1022 patients identified with VS, 221 received MB intraoperatively, and among them, 60 patients received MB within 15 min after the diagnosis of VS. After early MB application, mean arterial pressure was significantly higher, and vasopressor support was significantly lower within the first hour (p = 0.015) after the diagnosis of vasoplegia, resulting in a lower cumulative amount of norepinephrine (p = 0.018) and vasopressin (p = 0.003). The intraoperative need of fresh frozen plasma in the intervention group was lower compared to the control group (p = 0.015). Additionally, the intervention group had higher creatinine values in the first three postoperative days (p = 0.036) without changes in dialysis incidence. The 90-day survival did not differ significantly (p = 0.270). Conclusion: Our results indicate the additive effects of MB use during VS compared to standard vasopressor therapy only. Early MB administration for VS may significantly improve the patients’ hemodynamics with minor side effects.

Anesthesiology for Trauma Medicine: Roles, Medications, Airway Management, and Multidisciplinary Team Coordination

“…While primarily used as a contrast agent, methylene blue (MB) has shown utility as an adjunctive treatment for severe vasoplegia in cardiac surgery and septic shock [41]. The mechanism of action involves direct inhibition of nitric oxide as well as the inhibition of soluble guanylyl cyclase (sGC), which is a peptide (classify) that increases cyclic guanosine monophosphate (c-GMP) [41,42]. cGMP then causes relaxation of blood vessels.…”

Efficacy and safety of methylene blue in patients with vasodilatory shock: A systematic review and meta-analysis

“…The full-text screening excluded 102 studies for the reasons shown in Figure 1. Finally, 15 studies (12,16,(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35) were included in this meta-analysis. Among these, 7 studies were published in Chinese, and the other 8 studies were published in English.…”

Vasoplegic Syndrome after Cardiopulmonary Bypass in Cardiovascular Surgery: Pathophysiology and Management in Critical Care

“…MB acts by inhibiting NO-dependent vasodilation via three distinct mechanisms: direct scavenging of NO, inhibition of NO synthase, and most significantly, inhibition of guanylyl cyclase [ 97 , 98 , 99 , 100 ]. Several investigations in cardiac surgery patients (reviewed in [ 113 ].…”

“…Levin et al randomized 56 patients with established post-operative VS to receive either MB (1.5 mg/kg) or placebo, and reported a significant reduction in mortality with MB (0% vs. 21.4%, p = 0.01) [ 115 , 116 , 117 ]. In a retrospective analysis of 221 patients with per-operative vasoplegia treated with MB (2 mg/kg), Kofler et al reported improved hemodynamic status, but unchanged 90-day mortality [ 113 ]. In contrast to these data, Weiner et al found, in a retrospective cohort of 226 patients with post-operative VS, that treatment with MB (57 patients) was an independent predictor of in-hospital mortality ( p = 0.007) and post-operative complications ( p = 0.001).…”