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Open Access Highly Accessed Research

Calorie intake and patient outcomes in severe acute kidney injury: findings from The Randomized Evaluation of Normal vs. Augmented Level of Replacement Therapy (RENAL) study trial

Rinaldo Bellomo1*, Alan Cass2, Louise Cole3, Simon Finfer4, Martin Gallagher5, Joanne Lee5, Serigne Lo6, Colin McArthur7, Shay McGuinness8, John Myburgh9, Robyn Norton10, Carlos Scheinkestel11 and The RENAL Study Investigators

Author Affiliations

1 Department of Intensive Care, Austin Hospital, Studley Rd, Heidelberg, Melbourne, Victoria 3084, Australia

2 Nephrology Division, The George Institute for International Health, Level 10, King George V Building, Missenden Road, Camperdown, Sydney, New South Wales 2050, Australia

3 Department of Intensive Care, Nepean Hospital, PO Box 63, Penrith, Sydney, New South Wales 2715, Australia

4 Department of Intensive Care, Royal North Shore Hospital, Pacific Highway, St Leonards, Sydney, New South Wales 2065, Australia

5 Division of Nephrology, The George Institute for International Health, Level 10, King George V Building, Missenden Road, Camperdown, Sydney, New South Wales 2050, Australia

6 Division of Biostatistics, The George Institute for International Health, Level 10, King George V Building, Missenden Road, Camperdown, Sydney, New South Wales 2050, Australia

7 Department of Critical care Medicine, Auckland City Hospital, Park Rd, Grafton 1142, Auckland, New Zealand

8 Department of Cardiothoracic and Vascular Intensive Care, Auckland City Hospital, Park Rd, Grafton 1142, Auckland, New Zealand

9 Department of Intensive Care, St George Hospital, Gray Street, Kogarah, Sydney, New South Wales 2217, Australia

10 The George Institute for International Health, Level 10, King George V Building, Missenden Road, Camperdown, Sydney, New South Wales 2050, Australia

11 Department of Intensive Care, Alfred Hospital, Commercial Rd, Prahran, Melbourne, Victoria 3181, Australia

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Critical Care 2014, 18:R45  doi:10.1186/cc13767


Please see related commentary by Casaer: http://ccforum.com/content/18/3/140

Published: 14 March 2014

Abstract

Introduction

Current practice in the delivery of caloric intake (DCI) in patients with severe acute kidney injury (AKI) receiving renal replacement therapy (RRT) is unknown. We aimed to describe calorie administration in patients enrolled in the Randomized Evaluation of Normal vs. Augmented Level of Replacement Therapy (RENAL) study and to assess the association between DCI and clinical outcomes.

Methods

We performed a secondary analysis in 1456 patients from the RENAL trial. We measured the dose and evolution of DCI during treatment and analyzed its association with major clinical outcomes using multivariable logistic regression, Cox proportional hazards models, and time adjusted models.

Results

Overall, mean DCI during treatment in ICU was low at only 10.9 ± 9 Kcal/kg/day for non-survivors and 11 ± 9 Kcal/kg/day for survivors. Among patients with a lower DCI (below the median) 334 of 729 (45.8%) had died at 90-days after randomization compared with 316 of 727 (43.3%) patients with a higher DCI (above the median) (P = 0.34). On multivariable logistic regression analysis, mean DCI carried an odds ratio of 0.95 (95% confidence interval (CI): 0.91-1.00; P = 0.06) per 100 Kcal increase for 90-day mortality. DCI was not associated with significant differences in renal replacement (RRT) free days, mechanical ventilation free days, ICU free days and hospital free days. These findings remained essentially unaltered after time adjusted analysis and Cox proportional hazards modeling.

Conclusions

In the RENAL study, mean DCI was low. Within the limits of such low caloric intake, greater DCI was not associated with improved clinical outcomes.

Trial registration

ClinicalTrials.gov number, NCT00221013