Effects of extracorporeal CO removal on gas exchange and ventilator settings: a systematic review and meta-analysis.

Purpose: A systematic review and meta-analysis to evaluate the impact of extracorporeal carbon dioxide removal (ECCOR) on gas exchange and respiratory settings in critically ill adults with respiratory failure.

Methods: We conducted a comprehensive database search, including observational studies and randomized controlled trials (RCTs) from January 2000 to March 2022, targeting adult ICU patients undergoing ECCOR. Primary outcomes were changes in gas exchange and ventilator settings 24 h after ECCOR initiation, estimated as mean of differences, or proportions for adverse events (AEs); with subgroup analyses for disease indication and technology. Across RCTs, we assessed mortality, length of stay, ventilation days, and AEs as mean differences or odds ratios.

Results: A total of 49 studies encompassing 1672 patients were included. ECCOR was associated with a significant decrease in PaCO, plateau pressure, and tidal volume and an increase in pH across all patient groups, at an overall 19% adverse event rate. In ARDS and lung transplant patients, the PaO/FiO ratio increased significantly while ventilator settings were variable. "Higher extraction" systems reduced PaCO and respiratory rate more efficiently. The three available RCTs did not demonstrate an effect on mortality, but a significantly longer ICU and hospital stay associated with ECCOR.

Conclusions: ECCOR effectively reduces PaCO and acidosis allowing for less invasive ventilation. "Higher extraction" systems may be more efficient to achieve this goal. However, as RCTs have not shown a mortality benefit but increase AEs, ECCOR's effects on clinical outcome remain unclear. Future studies should target patient groups that may benefit from ECCOR. PROSPERO Registration No: CRD 42020154110 (on January 24, 2021).