Supplementary Material for: Extracorporeal Carbon Dioxide Removal in Patients with Acute Respiratory Distress Syndrome or Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

Background: Extracorporeal carbon dioxide removal (ECCO2R) was used to prevent invasive mechanical ventilation and associated mechanical damage in patients with acute respiratory distress syndrome (ARDS). Objectives: This study aimed to investigate the efficacy and safety of ECCO2R treatment in patients with ARDS or chronic obstructive pulmonary disease (COPD). Methods: MEDLINE, EMBASE, and the Cochrane Library were systematically searched for relevant studies that reported patient prognosis, blood gas parameters, and ECCO2R-related adverse events (AEs) published as of September 2020. Odds ratios (ORs), weighted mean differences (WMDs), and their corresponding 95% confidence intervals (CIs) were used to compare the outcomes. Results: Fifteen studies involving 532 ARDS or COPD patients were included. Compared with controls, ECCO2R did not influence the 28-day mortality (OR = 0.73, 95% CI: 0.28–1.87, p = 0.51), the length of hospital stay (WMD = 3.34, 95% CI: −5.22 to 11.90, p = 0.444), and the length of intensive care unit stay (WMD = −0.39, 95% CI: −8.76 to 7.99, p = 0.928). Compared with baseline values, partial pressure of carbon dioxide (PaCO2) in the ECCO2R group was significantly reduced, while the ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2) and pH increased. The overall rate of ECCO2R-related AEs was 35% (95% CI: 17–53%, p < 0.001), and bleeding was the most common AE with a rate of 22% (95% CI: 13–31%, p = 0.002). The rate of ECCO2R-related deaths was low. Conclusions: In conclusion, there was no statistically significant difference in the prognosis of patients with and without ECCO2R treatment. ECCO2R significantly reduced PaCO2 and improved PaO2/FiO2 and pH values in patients with ARDS or COPD. Bleeding was the most common ECCO2R-related AE.