Methylene Blue in Sepsis: A Randomized Controlled Trial

Overview

The purpose of this study is to investigate whether the addition of Methylene Blue to the standard treatment of septic shock will reduce vasopressor requirements

The management of severe infections, sepsis and septic shock is a serious problem facing physicians. Septic shock kills 10,000 Canadians every year. It is the most common cause of death in intensive units and the rates of sepsis and septic shock continue to increase annually. Septic shock is a complex interaction between pathologic vasodilation, relative and absolute hypovolemia, myocardial depression, and altered microvascular function resulting from a systemic inflammatory response to infection. After restoration of the circulating volume, many patients continue to suffer from a maldistribution of blood flow. Current hypotheses suggest that global indicators of hypoperfusion (serum lactate, hypotension, decreased oxygen delivery) represent an averaging of areas of normal or increased blood flow with areas where blood flow is decreased. These under-perfused areas become more hypoxic. The resulting tissue damage leads to more inflammation and more maldistribution, perpetuating a vicious cycle progressing on to death. Vasopressive agents are used in an attempt to maintain mean arterial blood pressure and restore perfusion, but these agents work globally, potentially worsening blood flow to the under-perfused areas. As well, many vasopressors have deleterious side effects such as metabolic and endocrine functions, and changes to regional blood flow. The microvascular changes are mediated by primarily nitric oxide (NO). Baseline levels of nitric oxide are produced by constitutive Nitric Oxide Synthase (cNOS), with NO levels measured in the nano-molar range. Inflammatory mediators cause increased production of inducible Nitric Oxide Synthase (iNOS) leading to NO levels measured in the micro-molar range. Suppression of nitric oxide production using non-specific NOS inhibitors has had discouraging results. Methylene Blue is a selective iNOS inhibitor. The purpose of this pilot study is to confirm safety and demonstrate signs of benefit in the use of methylene blue in sepsis. In particular, this study will examine whether the addition of methylene blue to standard early goal directed therapy in sepsis will reduce vasopressor requirements.

Conditions

Interventions

Eligibility

Outcomes