Clinical Outcomes and Complications of Extracorporeal Membrane Oxygenation (ECMO) in Adult Patients With COVID-19 in Central and Eastern Europe: A Systematic Review and Meta-Analysis.

BACKGROUND Extracorporeal membrane oxygenation (ECMO) is a rescue therapy for severe COVID-19-related acute respiratory distress syndrome (ARDS). International datasets do not consistently report Central and Eastern Europe (CEE) separately. We aimed to assess mortality, clinical characteristics, and complications of ECMO-treated COVID-19 patients across the CEE region. MATERIAL AND METHODS We conducted a systematic review with single-arm meta-analyses of observational studies. PubMed, Scopus, Embase, and Web of Science were searched from January 2020 to August 2025 for studies reporting ECMO outcomes in adult (≥18 years) COVID-19 patients from CEE countries, with at least 10 ECMO-treated patients. Conference abstracts and overlapping cohorts were excluded. The study protocol was registered with PROSPERO (CRD420251077593). RESULTS Twelve studies included 802 patients from 6 countries. Pooled in-hospital mortality was 65% (95% CI 0.57-0.72; I²=70.6%; 10 studies; n=691), and ICU mortality was 61% (95% CI 0.47-0.74; I²=85.8%; 7 studies, n=526). Country-level in-hospital mortality estimates were 54% for the Czech Republic and 76% for Poland but were descriptive because of the small number of studies and wide CIs. Mean pre-ECMO mechanical ventilation duration was 4.8 days (95% CI 3.7-5.8; I²=4.4%), ECMO duration was 17.8 days (95% CI 12.8-22.9; I²=79.8%), and ICU length of stay was 23.6 days (95% CI 7.5-39.7; I²=92.6%). Serious bleeding occurred in 40% (95% CI 22-61%; I²=85.7%). Certainty was very low for all pooled outcomes. CONCLUSIONS These CEE-specific estimates provide regional benchmarks, but substantial heterogeneity and very low certainty limit international comparisons and country-level interpretation. Standardized regional registries, prospective multicenter data, harmonized complication reporting, and long-term outcome assessment are needed.