Factors associated with poor outcomes of continuous renal replacement therapy

Abstract

Continuous renal replacement therapy (CRRT) is one of the dialysis modalities for critically ill patients. Despite intensive dialysis care, a high mortality rate is found in these patients. Our objective was to investigate the factors associated with poor outcomes in these patients. We conducted a retrospective cohort study using the National Health Insurance Research Database. Records of critically ill patients who received CRRT between 2007 and 2011 were retrieved, and the patients were categorized into two groups: those with acute kidney injury (AKI) and those with history of end-stage renal disease (ESRD). Our primary and secondary outcomes were in-hospital mortality and long-term survival and non-renal recovery (long-term dialysis dependence), respectively, in the AKI group. We enrolled 15,453 patients, with 13,204 and 2249 in the AKI and ESRD groups, respectively. Overall, 66.5% patients died during hospitalization. In-hospital mortality did not differ significantly between groups (adjusted odds ratio, 0.93; 95% CI, 0.84-1.02). Age, chronic liver disease, and cancer history were identified as independent risk factors for in-hospital mortality in both groups. Hypertension was associated with higher risk of in-hospital mortality in patients with AKI. Age, coronary artery disease, and admission to the medical intensive care unit (MICU) were risk factors for long-term dialysis dependence in patients with AKI. Patients with AKI and ESRD have similarly poor outcomes after CRRT. Older age and presence of chronic liver disease and cancer were associated with higher mortality. Older age, presence of coronary artery disease, and admission to MICU were associated with lower renal recovery rate in patients with AKI.

Fig 1. Flowchart of patient selection.

AKI: acute kidney injury, CRRT: continuous renal replacement therapy, ESRD: end-stage renal disease.

Fig 2. Kaplan–Meier survival curves for long-term survival.

(A) Total population (HR 0.98, 95% CI 0.93–1.03; adjusted HR 1.02, 95% CI 0.97–1.07) (B) Patients who survived and discharged from index hospitalization (HR 1.16, 95% CI 1.05–1.28; adjusted HR 1.21, 95% CI 1.09–1.34).