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Updated: May 13, 2026
An Optimized Evans Blue Protocol to Assess Vascular Leak in the Mouse
Published on: September 12, 2018
Methylene blue as a vasopressor: a meta-analysis of randomised trials
Laura Pasin1, Michele Umbrello, Teresa Greco
1Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Milan, Italy. pasin.laura@hsr.it
Objective:
To evaluate the efficacy of methylene blue in raising mean arterial pressure in hypotensive patients.
Design:
A meta-analysis of randomised controlled trials.
Data Sources:
We searched BioMedCentral, PubMed, Embase and the Cochrane Central Register of clinical trials.
Data Extraction:
Inclusion criteria were random allocation to treatment and comparison of methylene blue versus any comparator. Exclusion criteria were duplicate publications, non-adult studies and no data on main outcomes. The primary end point was mean arterial blood pressure value 1 hour after the study drug administration; the secondary end points were mortality at the longest follow-up available, and cardiac index.
Data Synthesis:
Data from 174 patients in five randomised controlled studies were analysed. Mean arterial pressure rose in patients receiving methylene blue (weighted mean difference = 6.93 mmHg; 95% CI, 1.67 to 12.18; P for effect = 0.01; P for heterogeneity = 0.17; I2 = 41%). Only two studies reported the values of cardiac index with a non-statistically significant improvement in the methylene blue group (mean difference = 0.76 L/min/m2; 95% CI, ? 0.32 to 1.84; P for effect = 0.2). The overall mortality rate was 16% (14/88) among methylene blue treated patients and 23% (20/86) in the control group (odds ratio = 0.65; 95% CI, 0.21 to 2.08; P for effect = 0.5).
Conclusions:
Methylene blue increases arterial blood pressure and systemic vascular resistances in vasoplegic patients without a detrimental effect on survival.
