Can Use of Intravenous Methylene Blue Improve the Hemodynamics and Outcome of the Patients with Refractory Septic Shock? An Observational Study

Abstract

Introduction: Refractory shock, which fails to respond to conventional vasopressor therapy, is a common complication of sepsis. Methylene blue has emerged as a potential adjunctive treatment option for reversing refractory shock in sepsis. The aim of this study was to evaluate the impact of intravenous methylene blue infusion on hemodynamic improvement and mortality in patients with refractory shock. Methodology: This was an observational prospective study for the duration of six months conducted at intensive care a medical college and teaching hospital including 76 patients with a diagnosis of septic shock requiring vasopressor therapy. Intravenous (IV) methylene blue was infused as bolus dose with 2 mg/kg dose in 20 minutes and its response to mean arterial blood pressure, decrease in vasopressor therapy, lactate level, and urine output was recorded in next 2 hours. Patients with improvement in mean arterial pressure (MAP) by 10% or decrease in vasopressor therapy in next 2 hours were leveled as responder. The length of intensive care unit (ICU) stay, duration of mechanical ventilation, incidence of acute kidney injury (AKI), and mortality were compared between responder and non-responder. Results: A total of 76 patients with refractory shock were included in the study. With the use of IV methylene blue, 41 (53.9%) patients showed significant improvement in MAP within 2 hours (70.17 ± 8.30 vs 64.28 ± 11.84, p = 0.005). Responders were 4.019 times more likely to have vasopressor-free time within 24 hours (18.4% vs 5.3%, p = 0.020, odds ratio 4.019, 95% confidence interval, 1.180–13.682). However, there was no significant difference in terms of mortality, length of ICU stay, ventilator free days, and incidence of AKI. In the responder group, there was a significant increase in the MAP and decrease in vasopressor requirement pre-and post-infusion of methylene blue (p < 0.05). Responder had shorter vasopressor-free days as compared with non-responder (5.34 vs 6.79, p = 0.008) while the mean survival time was longer with responders (21.97 vs 15.93 days, p = 0.024). Conclusion: The use of IV methylene blue in refractory shock as an adjuvant therapy significantly improved the mean arterial blood pressure and decreased the requirement of vasopressor therapy as well as improvement in the survival time. However, there was no change in the mortality, length of ICU stay, ventilator-free days, or incidence of AKI in the patients.