Risk factors for mortality in patients undergoing continuous renal replacement therapy after cardiac surgery

Abstract

Background: To investigate the risk factors for mortality in patients with acute kidney injury requiring continuous renal replacement therapy (AKI-CRRT) after cardiac surgery. Methods: In this retrospective study, patients who underwent AKI-CRRT after cardiac surgery in our centre from January 2015 to January 2020 were included. Univariable and multivariable analyses were performed to identify the risk factors for in-hospital mortality. Results: A total of 412 patients were included in our study. Of these, 174 died after AKI-CRRT, and the remaining 238 were included in the survival control group. Multivariable logistic regression analysis revealed that EuroSCORE > 7 (odds ratio [OR], 3.72; 95% confidence interval [CI], 1.92–7.24; p < 0.01), intraoperative bleeding > 1 L (OR, 2.14; 95% CI, 1.19–3.86; p = 0.01) and mechanical ventilation time > 70 h (OR, 5.03; 95% CI, 2.40–10.54; p < 0.01) were independent risk factors for in-hospital mortality in patients who had undergone AKI-CRRT. Our study also found that the use of furosemide after surgery was a protective factor for such patients (odds ratio, 0.48; 95% confidence interval, 0.25–0.92; p = 0.03). Conclusions: In summary, the mortality of patients with AKI-CRRT after cardiac surgery remains high. The EuroSCORE, intraoperative bleeding and mechanical ventilation time were independent risk factors for in-hospital mortality. Continuous application of furosemide may be associated with a better outcome.