Renal replacement therapy is an independent risk factor for mortality in critically ill patients with acute kidney injury

Monique M Elseviers,Patricia Van Der Niepen,Robert L Lins,Eric Hoste,Manu L Malbrain,Pierre Damas,Jacques Devriendt

doi:10.1186/cc9355

Abstract

IntroductionOutcome studies in patients with acute kidney injury (AKI) have focused on differences between modalities of renal replacement therapy (RRT). The outcome of conservative treatment, however, has never been compared with RRT.MethodsNine Belgian intensive care units (ICUs) included all adult patients consecutively admitted with serum creatinine >2 mg/dl. Included treatment options were conservative treatment and intermittent or continuous RRT. Disease severity was determined using the Stuivenberg Hospital Acute Renal Failure (SHARF) score. Outcome parameters studied were mortality, hospital length of stay and renal recovery at hospital discharge.ResultsOut of 1,303 included patients, 650 required RRT (58% intermittent, 42% continuous RRT). Overall results showed a higher mortality (43% versus 58%) as well as a longer ICU and hospital stay in RRT patients compared to conservative treatment. Using the SHARF score for adjustment of disease severity, an increased risk of death for RRT compared to conservative treatment of RR = 1.75 (95% CI: 1.4 to 2.3) was found. Additional correction for other severity parameters (Acute Physiology And Chronic Health Evaluation II (APACHE II), Sequential Organ Failure Assessment (SOFA)), age, type of AKI and clinical conditions confirmed the higher mortality in the RRT group.ConclusionsThe SHARF study showed that the higher mortality expected in AKI patients receiving RRT versus conservative treatment can not only be explained by a higher disease severity in the RRT group, even after multiple corrections. A more critical approach to the need for RRT in AKI patients seems to be warranted.

Highlights

Outcome studies in patients with acute kidney injury (AKI) have focused on differences between modalities of renal replacement therapy (RRT)
In this multi-center SHARF4 study, including 1,303 consecutively admitted AKI patients, we found significant differences in outcome between patients receiving conservative treatment and those treated with RRT
Despite our attempts to control for bias, including all available and possible confounders in the multi variable model, a number of well designed clinical trials will be needed to obtain more definitive conclusions. This cohort study of 1,303 AKI patients consecutively admitted to the intensive care units (ICUs) confirmed that mortality is equal in patients treated with intermittent or continuous RRT

Summary

Introduction

Outcome studies in patients with acute kidney injury (AKI) have focused on differences between modalities of renal replacement therapy (RRT). Acute kidney injury (AKI) occurs in up to 25% of critically ill patients admitted to the Intensive Care Unit (ICU) [1]. Despite well-established supportive care and technical advances in renal replacement therapy (RRT), mortality remains remarkably high in these patients. A review by YP Ympa and colleagues, including 80 studies covering 15,897 patients, revealed that mortality rates remained unchanged at around 50% over the last 50 years [2]. Conservative AKI treatment includes management of volume, electrolyte and acid-base homeostasis and specific drug management. There is a consensus that RRT is life saving and not starting RRT will lead to death in severely ill AKI patients, but data are lacking to generalize this opinion. Critics of the published studies, pointed to shortcomings such as lack of power, selection bias and disregarding differences in disease severity [10,15,16,17]

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