Clinical Predictors of Mortality of Patients With Acute Kidney Injury Requiring Renal Replacement Therapy

Abstract Background: Acute kidney injury (AKI) is frequently encountered around 40% in critically ill patients and associate with a high mortality particularly in AKI patients requiring renal replacement therapy (RRT). The objective of this study was to assess the clinical predictors for 28-day mortality in AKI patients requiring RRT.Methods: This is a retrospective cohort study from prospectively collected data over a year (2014-2015). AKI patients requiring RRT were included. We collected demographic and laboratory data of AKI patients requiring RRT within 24 hours before initiation of RRT. We excluded patients with pre-existing chronic kidney disease stage 5 and AKI patients requiring peritoneal dialysis. We compared clinical characteristics and analyzed the predictors of mortality of survivors and non-survivors according to 28-day mortality.Results: We included 122 AKI patients requiring RRT. Mortality rate at day 28 and 90 after AKI diagnosis were 59% (95% confidence interval [CI] 49.7-67.8) and 72.1% (95%CI 63.3-79.9). On multivariable analysis, clinical predictors for 28-day mortality were baseline serum creatinine (hazard ratio [HR] 0.57, 95% CI 0.36-0.90), SOFA score before initiation of RRT (HR 1.08, 95%CI 1.01-1.15), presence of vasopressors before initiation of RRT (HR 3.04, 95%CI 1.12-8.25), serum lactate > 4 mmol/L before initiation of RRT effect <10 days of survival time (HR 2.49, 95%CI 1.17-5.26), and serum lactate > 4 mmol/L before initiation of RRT effect ≥10 days of survival time (HR 1.31, 95%CI 0.47-3.60).Conclusion: A lower baseline serum creatinine was associated with the mortality in AKI patients requiring RRT. SOFA score, presence of vasopressors, and a higher serum lactate before initiation of RRT are useful clinical predictors for the 28-day mortality.