Effects of extracorporeal CO2 removal on gas exchange and ventilator settings: a systematic review and meta-analysis

Abstract

Abstract Purpose A systematic review and meta-analysis to evaluate the impact of extracorporeal carbon dioxide removal (ECCO 2 R) 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 ECCO 2 R. Primary outcomes were changes in gas exchange and ventilator settings 24 h after ECCO 2 R 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. ECCO 2 R was associated with a significant decrease in PaCO 2 , 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 2 /FiO 2 ratio increased significantly while ventilator settings were variable. “Higher extraction” systems reduced PaCO 2 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 ECCO 2 R. Conclusions ECCO 2 R effectively reduces PaCO 2 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, ECCO 2 R’s effects on clinical outcome remain unclear. Future studies should target patient groups that may benefit from ECCO 2 R. PROSPERO Registration No : CRD 42020154110 (on January 24, 2021). Graphical abstract

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