(1628) Hemodynamic Response to Methylene Blue for Refractory Septic Shock

Introduction: Methylene blue, an inhibitor of nitric oxide synthase, is a promising treatment for vasoplegia to spare catecholamine vasopressors. Most literature is in patients with vasoplegia after cardiac surgery, and limited studies have examined its use in patients with septic shock. The objective of this study was to assess reduction in norepinephrine equivalents and mean arterial pressure (MAP) thirty minutes after methylene blue bolus in patients with refractory vasoplegia caused by septic shock.

Methods: This was a multicenter retrospective observational study of adult patients with refractory septic shock who received a methylene blue bolus. The primary outcomes were reduction in norepinephrine equivalents and increase in MAP 30 minutes after receipt of methylene blue.

Results: Forty-one patients were included in this study. The majority (95.1%) of patients received one methylene blue bolus. There was variation between bolus dosing with 22 (53.7%) receiving 2 mg/kg and 19 (46.3%) receiving 1 mg/kg. The median time from vasopressor initiation to bolus dose administration was 32.2 (15.1-61.6) hours. The median baseline norepinephrine equivalent dose was 1.24 (0.9-2.98) mcg/kg/min and the percent change from baseline to 30 minutes after methylene blue bolus was 0% (-3.24-0). There were no significant differences between norepinephrine equivalents or MAP between baseline and the 30-minute follow up or other time points.

Conclusions: Patients with refractory vasoplegia caused by septic shock did not achieve a statistically or clinically significant difference in vasopressor requirements or MAP; however, patients in this study had high vasopressor requirements at the time of methylene blue administration. Future studies should examine the effects of earlier methylene blue administration.