Acute kidney injury

Abstract

Successful renal recovery is a key goal of patient management during acute kidney injury in critically ill patients. However, limited information exists to guide clinicians as to what interventions might either decrease or increase the likelihood of renal recovery and especially renal recovery to dialysis independence. The purpose of this review is to analyse recent data and help clinicians with relevant therapeutic choices. Two large trials, the Acute Renal Failure Trial Network (ATN) and Randomized Evaluation of Normal versus Augmented Level Renal Replacement Therapy (RENAL), provide important evidence on the possible impact of choice of renal replacement therapy on renal recovery to dialysis independence. In the ATN trial in which intermittent haemodialysis (IHD) was delivered 5077 times, continued dialysis dependence by day 28 occurred in 45.2% of survivors, whereas in the RENAL study in which IHD was used 314 times, dialysis dependence at 28 days was 13.3%. These striking differences in favour of using continuous renal replacement therapy are supported by observational studies and a randomized controlled trial. Similarly the association of a positive fluid balance with poor outcomes has now been supported by multiple observational studies and multivariable logistic regression analysis. Both use of IHD and a positive fluid balance can delay renal recovery. Available evidence from randomized controlled trials and comparative analysis of their results as well as data from large observational studies suggest that the avoidance of IHD and of a positive fluid balance are likely to increase the speed of renal recovery and may prevent end-stage renal failure in selected high-risk patients with acute kidney injury.