Outcome in post-traumatic acute renal failure when continuous renal replacement therapy is applied early vs. late

Objective: To determine whether the timing of initiation of continuous renal replacement therapy (CRRT) affects outcome in patients with post-traumatic acute renal failure (ARF). Design: The medical records of patients treated with CRRT for post-traumatic ARF were retrospectively reviewed. Chi-square testing was used to test frequencies between groups, and Student's t -test was used to compare means. Setting: A Level I trauma center. Patients: 100 Adult trauma patients treated with CRRT for ARF from 1989 to 1997. Patients were characterized as “early” or “late” starters, based upon whether the blood urea nitrogen (BUN) was less than or greater than 60 mg/dl, prior to CRRT initiation. Results: The mean BUN of the early and late starters was 42.6 and 94.5 mg/dl, respectively (p < 0.0001). CRRT was initiated earlier in the hospital course of early starters compared to late starters (hospital day 10.5 vs 19.4, p < 0.0001). Creatinine clearance prior to CRRT did not differ statistically between the two groups. No significant difference was found between early and late starters with respect to Injury Severity Score, admission Glasgow Coma Scale, presence of shock at admission, age, gender distribution, or trauma type. Admission laboratory values including BUN, serum creatinine, lactate, and bilirubin as well as fluid and blood requirements in the first 24 h were statistically the same for the two groups, suggesting a similar risk of developing renal failure. Survival rate was significantly increased among early starters compared to late starters (39.0 vs 20.0 %, respectively, p = 0.041). Conclusions: This retrospective review indicates that an earlier initiation of CRRT, based on pre-CRRT BUN, may improve the rate of survival of trauma patients who develop ARF.