Renal Recovery from Severe Acute Kidney Injury Requiring Renal Replacement Therapy

Choi, Kyung A; Kwon, Jeong Ah; Kim, Young Hoon; Lee, Yu Ji; Oh, Ha Young; Kim, Dae Joong; Kim, Yoon Goo; Huh, Wooseong; Lee, Jung Eun

Abstract

PURPOSE
Acute tubular necrosis (ATN) is a serious complication in critically ill patients. This study investigated the renal outcome of severe ATN requiring RRT and prognostic factors for renal recovery.
METHODS
Between January 2000 and May 2008, surviving patients with presumed ATN requiring dialysis were analyzed retrospectively. Patients with pre-existing chronic kidney disease and other causes of ARF rather than ATN were excluded. Primary outcomes were complete renal recovery (CR) and dialysis withdrawal. CR was defined as a return to basal serum creatinine level or creatinine <1.5 mg/dL (male) or <1.3 mg/dL (female) without dialysis.
RESULTS
Of one hundred twenty two patients, 79 (65%) patients were male. The mean age was 54+/-16 years and 87 patients (71%) received continuous renal replacement therapy. 55% had ischemic ATN, 29% had septic ATN, and 16% had nephrotoxic ATN. Mean duration of dialysis was 12 (6-29) days. Dialysis withdrawal rate at 30 days and at 60 days after initiation of dialysis were 51% and 77 %, respectively. CR at 60 days after initiation was 50%. Multivariate analysis revealed that older age (per year, Hazard ratio (HR)=0.981, 95% Confidence interval (CI) 0.963 to 0.999), ischemic ATN (vs. toxic ATN, HR=0.481, 95% CI 0.238 to 0.974),and longer duration of oliguria (per day, HR=0.979, 95 % CI 0.962 to 0.996) were independent prognostic factors of renal recovery.
CONCLUSION
Young age and short duration of oliguria were favorable factors for renal recovery from ATN requiring dialysis. The cause of ATN might be also an independent prognostic factor.