Hydroxocobalamin Versus Methylene Blue for Treatment of Vasoplegic Shock Following Cardiopulmonary Bypass: A Systematic Review and Meta-analysis.

OBJECTIVES

To summarize the evidence of the hemodynamic effects and vasopressor requirements of adult cardiac surgery patients with vasoplegic shock treated with hydroxocobalamin or methylene blue.

DESIGN

Systematic review and meta-analysis.

SETTING

Multi-institutional.

PARTICIPANTS

Adult cardiac surgery patients with vasoplegic shock.

INTERVENTIONS: Administration of hydroxocobalamin or methylene blue.

MEASUREMENTS AND MAIN

RESULTS

A total of 263 patients in four retrospective observational studies were included in a pooled analysis. There was no significant difference in the primary outcome, vasopressor requirement at 1 hour (mean difference [MD]: 0.00 mcg/kg/min norepinephrine equivalent [NEE], 95% confidence interval [CI]: -0.09 to 0.08). Hydroxocobalamin was associated with a significant improvement in mean arterial pressure at 1 hour (MD: 5.30 mmHg, 95% CI: 2.98 to 7.62), total vasopressor dose at 1 hour (MD: -0.13 mcg/kg/min NEE, 95% CI: -0.25 to -0.01), total vasopressor at 6 hours (MD: -0.15 mcg/kg/min NEE, 95% CI: -0.21 to -0.08). No differences were observed in systemic vascular resistance or mortality between groups. Three studies were deemed at moderate risk of bias and one at serious risk.

CONCLUSIONS

Hydroxocobalamin has been shown to have a beneficial effect on hemodynamics and vasopressor requirements in vasoplegic cardiac surgery patients compared with methylene blue, although evidence is limited, and further well-powered randomized controlled trials are required.