Impact of timing of initiation of dialysis on mortality of patients with acute kidney injury

Introduction: In Brazil, primary studies on this issue are still limited and the ideal timing of initiation of dialysis in severe acute kidney injury (AKI) still generates disagreements among experts. Objectives: To assess if the timing of initiation of dialysis is associated with the mortality of patients with AKI in intensive care unit (ICU). Patients and Methods: We retrospectively analyzed medical records of patients that developed severe AKI in the ICU. Bivariate analysis was carried out to compare data between groups of patients who underwent early dialysis (ED - initiated up to two days after the AKI diagnosis) and late dialysis (LD – initiated more than two days after the AKI diagnosis), while multivariate logistic regression was applied to identify factors associated with mortality. Results: Of the 76 patients included in the study, 27 (35.5%) were allocated in the ED group and 49 (64.5%) in the LD group. LD group had a higher frequency of sepsis [26 (53%) vs. 12 (44%); P = 0.472], while the ED group had a higher median number of dialysis sessions (6 vs. 3; P = 0.477) and higher total median time on dialysis (17.5 h vs. 13 h; P = 0.629). The overall mortality rate was 61.8% (n = 47) and of 76% (n = 22) in the ED group. The patients’ serum creatinine level at admission in the ICU was the only statistically significant risk factor for death [OR= 0.453 (95% CI= 0.257–0.801); P = 0.006]. Conclusion: The overall and in the ED group mortality rate was elevated, however, the timing of initiation of dialysis did not show statistically significant association with death. The serum creatinine at ICU admission seems to be an important mortality predictor.