Abstract: Objective  To investigate the clinical efficacy of extracorporeal carbon dioxide removal (ECCO2R) therapy in patients with continuous renal replacement therapy combined with type Ⅱ respiratory failure. Methods  A retrospective analysis were performed, including 11 CRRT patients with type Ⅱ respiratory failure treated with ECCO2R in the intensive care unit (ICU) and 11 not treated CRRT patients with type Ⅱ respiratory failure as the control group from December 2020 to July 2022.  The results of blood gas analyses were collected from the patients before the treatment and 24 hours after the treatment. The changes in arterial blood carbon dioxide partial pressure (PaCO2), pH (acid-base), arterial blood oxygen partial pressure (PaO2), base remaining (BE), bicarbonate (HCO3-), and lactic acid (Lac) were compared between before and after the treatment.  Results Compared with the control group, PaCO2 was higher in the intervention group before the application of ECCO2R treatment (Z=2.988, P=0.002), but there was no significantly difference after the treatment (Z=-0.230, P=0.847). 24 hours after the application of ECCO2R treatment, pH (t=-3.656,  P=0.002), BE (t=3.185, P= 0.001), HCO3- (t=2.791, P=0.004), and Lac (Z=-2.397, P=0.016) were higher than in the control group. After the application of ECCO2R, pH was significantly higher (t=-2.948, P=0.008) and PaCO2 was significantly lower (Z=-3.447, P＜0.001) than before treatment in the intervention group. And there was no statistically significant change in PaO2 and hemodynamic parameters before and after treatment.  Conclusion  ECCO2R corrects hypercapnia in CRRT patients with type Ⅱ respiratory failure, but whether it has benefits to prognosis still requires large-scale clinical research.

Key words: Extracorporeal carbon dioxide removal, Continuous renal replacement therapy, Type II respiratory failure, Hypercapnia