Continuous renal replacement therapy outcomes in acute kidney injury and end-stage renal disease: a cohort study

Andrew S Allegretti,Ednan Bajwa,Jo David-Kasdan,David Jr Steele,Ishir Bhan,John L Niles

doi:10.1186/cc12780

Andrew S Allegretti, Ednan Bajwa + Show 4 more

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https://doi.org/10.1186/cc12780

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Abstract

IntroductionContinuous renal replacement therapy (CRRT) is a widely used but resource-intensive treatment. Despite its broad adoption in intensive care units (ICUs), it remains challenging to identify patients who would be most likely to achieve positive outcomes with this therapy and to provide realistic prognostic information to patients and families.MethodsWe analyzed a prospective cohort of all 863 ICU patients initiated on CRRT at an academic medical center from 2008 to 2011 with either new-onset acute kidney injury (AKI) or pre-admission end-stage renal disease (ESRD). We examined in-hospital and post-discharge mortality (for all patients), as well as renal recovery (for AKI patients). We identified prognostic factors for both in-hospital and post-discharge mortality separately in patients with AKI or ESRD.ResultsIn-hospital mortality was 61% for AKI and 54% for ESRD. In patients with AKI (n = 725), independent risk factors for mortality included age over 60 (OR 1.9, 95% CI 1.3, 2.7), serum lactate over 4 mmol/L (OR 2.2, 95% CI 1.5, 3.1), serum creatinine over 3 mg/dL at time of CRRT initiation (OR 0.63, 95% CI 0.43, 0.92) and comorbid liver disease (OR 1.75, 95% CI 1.1, 2.9). Among patients with ESRD (n = 138), liver disease was associated with increased mortality (OR 3.4, 95% CI 1.1, 11.1) as was admission to a medical (vs surgical) ICU (OR 2.2, 95% CI 1.1, 4.7). Following discharge, advanced age became a predictor of mortality in both groups (AKI: HR 1.9, 95% CI 1.2, 3.0; ESRD: HR 4.1, 95% CI 1.5, 10.9). At the end of the study period, only 25% (n = 183) of patients with AKI achieved dialysis-free survival.ConclusionsAmong patients initiating CRRT, risk factors for mortality differ between patients with underlying ESRD or newly acquired AKI. Long-term dialysis-free survival in AKI is low. Providers should consider these factors when assessing prognosis or appropriateness of CRRT.

Highlights

Continuous renal replacement therapy (CRRT) is a widely used but resource-intensive treatment
We found that 28% of surviving patients with acute kidney injury (AKI) and 40% of those with end-stage renal disease (ESRD) died in the period following discharge, suggesting that in-hospital mortality rates may underrepresent the impact of CRRT-associated disease on survival
We found that elevated blood urea nitrogen (BUN), both at admission and initiation of CRRT, were predictive of post-discharge mortality, in contrast to the protective association of an elevated creatinine in the inpatient settings

Summary

Introduction

Continuous renal replacement therapy (CRRT) is a widely used but resource-intensive treatment. Continuous renal replacement therapy (CRRT) is an important intervention in critically ill patients with fluid overload and metabolic disarray who are unable to tolerate the hemodynamic shifts of intermittent hemodialysis. It is expensive and resource intensive, incurring costs of up to several thousand US dollars per day [1,2]. We sought to address this deficit by identifying risk factors for in-hospital mortality in a cohort of patients with both AKI and ESRD who received CRRT, and continued to collect data to assess long-term outcomes following discharge

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