Objective

Extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT) are often used together to treat critically ill patients. This systematic review aims to assess mortality and renal recovery with this combination as reported by studies published over the past decade.

Methods

We searched PubMed, Web of Science, ProQuest Health & Medical Complete, Embase, and Ovid SP. Two reviewers independently screened studies and extracted data. Study quality was assessed using the Newcastle–Ottawa Scale (NOS) for non-randomized controlled trials. We performed statistical analyses with RevMan 5.4.

Results

Nineteen studies with 1,786 patients met the inclusion criteria. Of these, 1,021 patients were in the ECMO-alone group (495 deaths, 48.5, %) and 765 were in the ECMO with CRRT group (395 deaths, 51.6%). The pooled effect showed no statistically significant difference in mortality between groups (OR 1.2, 95% CI 0.99–1.46, p = 0.07), though heterogeneity was high (I² = 51%). However, when excluding one study which appeared to be driving this heterogeneity in a sensitivity analysis, mortality was significantly higher among patients treated with ECMO and CRRT (OR 1.43, 95% CI 1.15–1.77, p = 0.001). Subgroup analysis of only adult retrospective studies also yielded a higher mortality rate with ECMO and CRRT (OR 1.42, 95% CI 1.13–1.78; p = 0.003). No difference in mortality was seen when pooling the two paediatric retrospective studies (OR 0.90, 95% CI 0.68–1.19; p = 0.45) or the two prospective studies (OR 0.94, 95% CI 0.31–2.83, p = 0.91). Limited data on recovery of renal function prevented further analysis.

Conclusion

In conclusion, in contrast to older data, our pooled analysis of recent studies revealed no significant increase in mortality risk associated with CRRT use in patient treated with ECMO. However, after accounting for heterogeneity, mortality remained higher in patients treated with ECMO and CRRT group than in the ECMO-alone group. Additional prospective data are essential to clarify the impact of CRRT on outcomes in patients treated with ECMO.