Epidemiology of renal recovery after acute renal failure

PURPOSE OF REVIEW: Recovery of renal function after acute renal failure is an important clinical determinant of patient morbidity. Herein, the epidemiology of renal recovery after acute renal failure will be described, along with potential predictive factors and interventions. RECENT FINDINGS: Renal recovery has been variably defined, most often as recovery to independence from renal replacement therapy. A recent consensus definition for acute renal failure has been published and included provisions for defining renal recovery. Renal recovery to renal replacement therapy independence occurs in the majority by hospital discharge and peaks by 90 days. All of older age, female sex, co-morbid illnesses, especially chronic kidney disease, and late initiation of renal replacement therapy or conventional intermittent renal replacement therapy have been coupled with non-recovery. Analysis of the literature suggests several interventions may influence recovery. SUMMARY: The prognosis is generally good for recovery after acute renal failure. Most patients will be independent of renal replacement therapy by 90 days. Additional research is necessary, however, to understand recovery rates not only to independence from renal replacement therapy, but also to complete and partial recovery. Future studies need to consider the health economic implications for survival and non-recovery. Finally, questions on the role of various interventions require characterization in randomized controlled trials to determine how they may influence renal prognosis.