Continuous renal replacement therapy for the treatment of acute kidney injury

Continuous renal replacement therapy (CRRT) has been widely used for treating critically ill patients with acute kidney injury (AKI). Whether CRRT is better than intermittent hemodialysis for the treatment of AKI remains controversial. We sought to identify the clinical features that can predict survival for the patients who are treated with CRRT.

We analyzed the data of 125 patients who received CRRT between 2005 and 2007. We identified the demographic variables, the underlying diagnoses, the duration of CRRT, the mean arterial blood pressure (ABP) and the Simplified Acute Physiology Score (SAPS) II. The classification/staging system for acute kidney injury (AKI) was applied to all the patients, who were then divided into stage 1-3 subgroups.

The average age of the patients was 61.414.3 years and the mortality rate was 60% (75 of 125 patients). The survivors had a significantly higher mean ABP and a higher mean serum bicarbonate level, which were measured the day after CRRT, than the nonsurvivors (86.723.7 vs. 69.224.6 mm Hg, respectively, 21.43.5 vs. 16.45.4 mmol/L, respectively,; p<0.05 for each). The stage 3 AKI patients showed the worst parameters for the SAPS II score and the serum levels of creatinine and blood urea nitrogen. The mortality rate was higher for the stage 3 subgroup than the other groups (70.5%, p<0.05).

The patients with AKI and who require CRRT continue to have a high mortality rate. A higher mean ABP and a higher serum bicarbonate level measured the day after CRRT may predict a more favorable prognosis. The staging system for AKI can improve the ability to predict the outcomes of CRRT patients.