Meta-analysesDelivery of full predicted energy from nutrition and the effect on mortality in critically ill adults: A systematic review and meta-analysis of randomised controlled trials☆
Introduction
Nutrition therapy is a widely provided intervention to critically ill patients internationally but there is uncertainty as to the amount of energy that should be provided to optimise outcomes. Several randomised controlled trials (RCTs) have compared the delivery of less than predicted energy requirements in both arms (60–70%) or to even lesser amounts (20–30%) [2], [3], [4]. It can be argued that failing to compare delivery of energy close to targeted requirements risks flawed interpretation and does not reflect current best practice recommendations [5], [6], [7], [8].
The results of the aforementioned trials have been mixed and confusing for clinicians. Methodologies such as systematic reviews and meta-analyses have been utilised to try and combine trial results and obtain guidance. Five published meta-analyses have investigated the role of energy delivery at varying amounts to critically ill adults and the association with clinical outcomes [9], [10], [11], [12], [13]. None have however specifically focused on studies which aim to deliver near target energy levels recommended in best practice guidelines, or completed a quality assessment across outcomes, significantly limiting confidence and clinical utility of the findings [14].
The aim of this systematic review and meta-analysis was to assess the effect of near target energy provision from nutrition (defined as provision of ≥80% of the predicted energy determined by any method) on mortality and other important clinical outcomes in critically ill adults including detailed assessments of evidence quality.
Section snippets
Methods
Methodologies detailed by expert groups and best practice guidelines were utilised in this review [15], [16], [17].
The question posed was “In critically ill adults (population), does delivery of full predicted energy from nutrition (intervention) influence mortality or other important clinical outcomes (outcome) compared to delivery of less than full predicted energy from nutrition (comparator)?” Full details can be viewed on PROSPERO (CRD42015027512) or in the pre-published protocol [1]. In
Results
There were 9335 papers identified and after duplicates and irrelevant papers were excluded on abstracts alone, 509 underwent full text review. Ten papers were eligible including 3155 participants (Fig. 1) [3], [21], [22], [23], [24], [25], [26], [27], [28], [29].
The included trials were conducted in a variety of locations and over a wide range of years (4 in Europe, 2 in the United Kingdom and 1 each in Israel, Australia, Asia and the United States of America between 1997 and 2015). Six studies
Key findings
This systematic review and meta-analysis did not find any associations with delivery of energy at near target (≥80% of predicted amounts), compared to standard care (<80% of predicted amounts) and important clinical outcomes in critically ill adults. However, the quality of evidence for all primary and secondary outcomes was rated ‘very low’ using the GRADE assessment, indicating low confidence in this result. The novelty of this systematic review and meta-analysis is that randomised trials
Conclusions
The delivery of near target energy at ≥ 80% of predicted requirements, when compared to standard care energy delivery, did not influence mortality or any other relevant clinical outcomes in adult critically ill patients. However, the quality of most randomised trials was low, suggesting that the true estimate of effect may be different. Robust large prospective RCTs with consistent reporting are required to determine the optimal amount of energy provision in critical illness, and to provide
Author contribution to the manuscript
EJR and ARD had responsibility for the research design, performed the literature review, collected and analysed the data. EJR, ARD, CH, AD, MB and DJC provided crucial intellectual input to the analysis and interpretation of the results and drafting of the manuscript. All authors read and approved the final manuscript.
Conflict of interest
The authors have no relevant financial or personal disclosures in relation to this work.
Funding
This review was conducted as part of a PhD with funding from the National Health and Medical Research Council (APP1075288).
Disclaimer
ARD, AD and EJR are involved in the TARGET study which investigates the role of energy delivery in critically ill adults (NCT02306746).
Acknowledgements
Thank you to Lorena Romero, Senior Medical Librarian, The Ian Potter Library, Alfred Health for advice during the review.
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Effect of hypocaloric versus standard enteral feeding on clinical outcomes in critically ill adults – A meta-analysis of randomized controlled trials with trial sequential analysis
2021, Medicina IntensivaCitation Excerpt :Accordingly, hypocaloric enteral feeding rather than standard enteral feeding has been advocated by the European Society for Clinical Nutrition and Metabolism (ESPEN) to be applied in the early phase of critical illness,4 where hypocaloric feeding was defined as an energy administration below 70% of the defined target by ESPEN guidelines.4 In fact, a majority of randomized controlled trials (RCTs)8–13 failed to identify an beneficial effect on mortality with use of hypocaloric enteral feeding, several meta-analyses14–17 also revealed a neutral effects on mortality or other outcomes in critically ill patients, the efficacy and safety of hypocaloric feeding in critically ill patients is still controversial to date. Recently, more and more evidence showed that the dose of protein intake is associated with clinical outcomes in critically ill patients,18–20 there are even opinions that protein intake may be more important than caloric intake for improving clinical outcomes,21,22 it seems that protein intake might affect the effectiveness of hypocaloric feeding.
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2021, Clinical Nutrition ESPENCitation Excerpt :Second, the calorie content itself might not be as important as use of the gut. A systematic review comparing delivery of near target energy at ≥80% of predicted requirements and standard care energy delivery showed no differences in in-hospital outcomes [31]. Another meta-analysis comparing early enteral nutrition and early parenteral nutrition showed better in-hospital outcomes between the groups [14].
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2020, Clinical NutritionClinical Nutrition in Critical Care Medicine – Guideline of the German Society for Nutritional Medicine (DGEM)
2019, Clinical Nutrition ESPENCitation Excerpt :11 meta-analyses evaluated these RCTs (Table 6). For mortality, seven meta-analyses showed no difference between a mildly hypocaloric and a severely hypocaloric (enteral) nutrition [3,4,102–106], or between a largely eucaloric and a moderately hypocaloric diet (one meta-analysis) [107]. Three meta-analyses found a U-shaped relationship between calorie intake and mortality (minimum when 33.3–66.6% of target, or when a moderately hypocaloric diet was provided) [56–58].