Effect of CRRT combined with low-flow ECMO on canines with ARDS and hypercapnia

Abstract

To observe the effect of continuous renal replacement therapy (CRRT) combined with low-flow extracorporeal membrane oxygenation (ECMO) of V-V mode on anti-inflammation, improving oxygenation and reducing P_aCO₂ in canines with acute respiratory distress syndrome (ARDS) and hypercapnia. A total of 30 healthy adult canines were randomly divided into sham group (n = 10), ECMO (EC) group (n = 10) and CRRT + ECMO (CR + EC) group (n = 10). Sham group was only treated with invasive mechanical ventilation. EC group was also treated with ECMO. CR + EC group was treated with CRRT combined with low-flow ECMO of V-V mode besides invasive mechanical ventilation. The results showed that hazard ratio was lower in the CR + EC group. Inflammatory factors, OI values, and PaCO₂ levels were lower in the CR + EC group. There was no significant difference in the levels of MAP, CO and T among the three groups. No significant complications or death was developed in the three groups. Compared with ECMO group at T3, T6 and T9, IL-6 [(276.13 ± 8.32, 262.04 ± 7.15, 259.33 ± 7.31)ng/L VS (352.67 ± 19.24, 360.24 ± 23.58, 362.21 ± 25.24)ng/L] and TNF-α [(50.14 ± 1.75, 50.45 ± 1.81, 48.03 ± 1.24) ng/L VS (70.25 ± 3.02, 72.45 ± 3.25, 76.69 ± 2.18)ng/L] in CR + EC group were decreased (P < 0.0001). Compared with sham group, IL-6 [(343.76 ± 21.97, 345.91 ± 19.89, 340.34 ± 22.17)ng/L]and TNF-α [(68.10 ± 2.96, 67.31 ± 3.01, 70.34 ± 3.35)ng/L] of T3, T6 and T9 in CR + EC group were lower (P < 0.0001). These findings indicated that CRRT combined with low-flow ECMO of V-V mode had a positive effect on anti-inflammation, oxygenation improvement and surplus blood CO₂ removal in canines with ARDS and hypercapnia. These results provide a promising treatment regimen for ARDS.

Keywords: Acute respiratory distress syndrome (ARDS); Continous renal replacement therapy (CRRT); Extracorporeal membrane oxygenation (ECMO).