ECMO Weaning Blood Processing: A Scoping Review

Extracorporeal membrane oxygenation (ECMO) has been widely used for life support in severe refractory cardiac and respiratory failure. During ECMO weaning, the circuit usually retains 500-800 mL of residual blood. Direct discarding leads to blood loss, increased anemia, and higher allogeneic transfusion requirements, while appropriate autologous blood reinfusion can reduce transfusion risks and medical costs. However, evidence on blood processing strategies during ECMO weaning remains scattered, and no unified clinical guidelines exist.

This scoping review strictly followed the PRISMA‑ScR 2018 checklist and JBI methodology. We systematically searched PubMed, Embase, Web of Science Core Collection, Cochrane Library, CNKI, and Wanfang from inception to March 28, 2026. Two reviewers independently screened literature, extracted data, and assessed quality. Descriptive synthesis and qualitative analysis were performed due to high heterogeneity and lack of randomized controlled trials (RCTs).

A total of 68 articles were retrieved, and 9 studies were finally included. The identified blood processing strategies were classified into four categories: blood cell salvage system (BCS) autologous reinfusion, pump-controlled blood reinfusion, modified CPD blood bag storage reinfusion, and direct discard.

Based on current observational evidence, autologous blood reinfusion during ECMO weaning appears feasible and is associated with favorable surrogate hematological outcomes compared with direct discard. Identified strategies differ in indications, operation, and costs, and may be selected individually according to ECMO mode, hemodynamic status, and institutional conditions. Given the limited number, low quality, and high heterogeneity of included studies, no conclusions regarding hard clinical outcomes can be drawn. This review highlights the urgency of high‑quality studies with long‑term clinical endpoints to further verify efficacy and safety.