Extracorporeal membrane oxygenation versus conventional therapy in patients with acute respiratory failure: systematic review with meta-analysis

Background: Acute respiratory distress syndrome (ARDS) is a severe condition where lung alveoli fill with fluid, depriving organs of oxygen and risking death. Mechanical ventilation is conventional for oxygen therapy, but extracorporeal membrane oxygenation (ECMO) may be needed for refractory ARDS cases. This study aims to compare ECMO's impact on mortality and hospital stay versus conventional treatment for patients aged 12 or older with moderate or severe ARDS in intensive care units (ICUs). Methodology: Four independent reviewers followed the PRISMA-P method for the review. The key question used the PICOS tool. Databases searched included Cochrane Library, Bireme, MEDLINE, EMBASE, Web of Science, Scielo, LILACS, and grey literature to minimize publication bias. Selected papers were randomized controlled trials (RCTs) without language restrictions, meeting predefined inclusion and exclusion criteria. RoB-2 assessed bias risk, and GRADE evaluated evidence quality. Mortality was analyzed using a fixed-effect PETO method (odds ratio), and hospital stay was treated as a continuous variable using inverse variance and standardized mean difference (SMD). Results: We found 3,774 articles and selected 6 studies with 1,050 participants. Of these, 519 were allocated to the intervention group (ECMO) and 531 to the conventional treatment group (MV). The risk of bias for 3 studies was some concerns, and 3 were high risk of bias, mainly due to deviations from intended/planned interventions and selection of reported outcomes. The primary outcomes for 30-day, 60-day, 90-day, and 180-day mortality showed odds ratios of 0.90 (95% CI: 0.66–1.21), 0.78 (95% CI: 0.50–1.21), 0.90 (95% CI: 0.66–1.21), and 0.62 (95% CI: 0.36–1.06) respectively, with low heterogeneity (I2 0.10). The secondary outcomes for a total length of stay and ICU stay showed standardized mean differences of 0.39 (95% CI: 0.13–0.65) and 0.33 (95% CI: 0.05–0.60) respectively, with substantial heterogeneity (I2 > 66% and p © The Author(s), under exclusive licence to The Brazilian Society of Biomedical Engineering 2024.