Antithrombin Supplementation in Extracorporeal Membrane Oxygenation: A Systematic Review With Meta-Analysis

The Extracorporeal Life Support Organization recommends daily antithrombin monitoring and supplementation to achieve > 50%-80% activity during extracorporeal membrane oxygenation (ECMO). Evidence supporting this practice is uncertain, and whether it confers clinical benefit or harm is unclear.

This was a systematic review with meta-analysis to evaluate the safety and efficacy of antithrombin supplementation during ECMO. We systematically searched databases and registers for studies comparing patients on ECMO who received antithrombin supplementation to those who did not. Random effects meta-analysis was performed. Risk of bias was independently assessed by two investigators. A priori subgroup and sensitivity analyses were performed to explore reasons for heterogeneity.

A total of 11 studies were identified. In the pooled meta-analysis, antithrombin supplementation resulted in no difference in bleeding events (OR 1.38, 95% CI, 0.88-2.17, p = 0.16), thrombotic events (OR 1.57, 95% CI, 0.84-2.90, p = 0.15), or mortality (OR 1.21, 95% CI, 0.81-1.81, p = 0.35) when compared to those who did not receive antithrombin. Subgroup analysis revealed no difference in bleeding events or mortality in pediatric or adult patients; however, pediatric patients that received antithrombin were more likely to experience a thrombotic event (OR 1.70, 95% CI, 1.51-1.91). Sensitivity analysis in only low risk of bias studies confirmed these findings.

Antithrombin supplementation was not associated with differences in mortality or hemostatic outcomes during ECMO support and may be associated with harm in pediatric patients on ECMO.