Risk factors for nosocomial infections in ECMO patients: a systematic review and meta-analysis

Background Nosocomial infection (NSI) is a serious complication in extracorporeal membrane oxygenation (ECMO) patients, yet reported risk factors remain inconsistent. A systematic synthesis is needed to identify key predictors. Methods Following PRISMA guidelines, this meta-analysis (PROSPERO: CRD420251161290) searched five databases for studies reporting multivariate risk factors for NSI in adult ECMO patients. Study selection, data extraction, and quality assessment (Newcastle-Ottawa Scale) were performed independently by two reviewers. Pooled odds ratios (ORs) were calculated with random-effects models; heterogeneity (I 2 ≥ 50%) was explored via meta-regression and subgroup analyses. Results Thirty-four observational studies (≈8,901 patients) were included. Significant risk factors were: immunosuppression (OR 2.21, 95% CI 1.27–3.85), inter-hospital transport (2.24, 1.04–4.80), pre-ECMO infection (2.54, 2.03–3.18), higher SOFA score (per point: 1.13, 1.03–1.24), prolonged ECMO duration (per day: 1.10, 1.07–1.14), continuous renal replacement therapy (2.18, 1.57–3.02), and catheter intubation (1.24, 1.02–1.51). ECMO duration showed high heterogeneity (I 2 = 89.9%), largely driven by small-study effects. Age, body mass index, diabetes mellitus, and hypertension were not significantly associated. Conclusion NSI in ECMO patients arises from an interplay of baseline characteristics, illness severity, and invasive support duration/intensity. A stratified, risk-factor-based prevention strategy is warranted. Given the predominantly retrospective evidence, prospective studies are required for validation. Systematic review registration https://www.crd.york.ac.uk/PROSPERO/view/CRD420251161290 , Identifier: CRD420251161290.