Background This guideline updates recommendations from the 2016 American Society for Parenteral and Enteral Nutrition (ASPEN)/Society of Critical Care Medicine (SCCM) critical care nutrition guideline for five foundational questions central to critical care nutrition support. Methods The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) process was used to develop and summarize evidence for clinical practice recommendations. Clinical outcomes were assessed for (1) higher vs lower energy dose, (2) higher vs lower protein dose, (3) exclusive isocaloric parenteral nutrition (PN) vs enteral nutrition (EN), (4) supplemental PN (SPN) plus EN vs EN alone, (5A) mixed‐oil lipid injectable emulsions (ILEs) vs soybean oil, and (5B) fish oil (FO)–containing ILE vs non‐FO ILE. To assess safety, weight‐based energy intake and protein were plotted against hospital mortality. Results Between January 1, 2001, and July 15, 2020, 2320 citations were identified and data were abstracted from 36 trials including 20,578 participants. Patients receiving FO had decreased pneumonia rates of uncertain clinical significance. Otherwise, there were no differences for any outcome in any question. Owing to a lack of certainty regarding harm, the energy prescription recommendation was decreased to 12–25 kcal/kg/day. Conclusion No differences in clinical outcomes were identified among numerous nutrition interventions, including higher energy or protein intake, isocaloric PN or EN, SPN, or different ILEs. As more consistent critical care nutrition support data become available, more precise recommendations will be possible. In the meantime, clinical judgment and close monitoring are needed. This paper was approved by the ASPEN Board of Directors.

BackgroundEnteral nutrition (EN) is recommended as the preferred route for early nutrition therapy in critically ill adults over parenteral nutrition (PN). A recent large randomized controlled trial (RCT) showed no outcome differences between the two routes. The objective of this systematic review was to evaluate the effect of the route of nutrition (EN versus PN) on clinical outcomes of critically ill patients.MethodsAn electronic search from 1980 to 2016 was performed identifying relevant RCTs. Individual trial data were abstracted and methodological quality of included trials scored independently by two reviewers. The primary outcome was overall mortality and secondary outcomes included infectious complications, length of stay (LOS) and mechanical ventilation. Subgroup analyses were performed to examine the treatment effect by dissimilar caloric intakes, year of publication and trial methodology. We performed a test of asymmetry to assess for the presence of publication bias.ResultsA total of 18 RCTs studying 3347 patients met inclusion criteria. Median methodological score was 7 (range, 2–12). No effect on overall mortality was found (1.04, 95 % CI 0.82, 1.33, P = 0.75, heterogeneity I2 = 11 %). EN compared to PN was associated with a significant reduction in infectious complications (RR 0.64, 95 % CI 0.48, 0.87, P = 0.004, I2 = 47 %). This was more pronounced in the subgroup of RCTs where the PN group received significantly more calories (RR 0.55, 95 % CI 0.37, 0.82, P = 0.003, I2 = 0 %), while no effect was seen in trials where EN and PN groups had a similar caloric intake (RR 0.94, 95 % CI 0.80, 1.10, P = 0.44, I2 = 0 %; test for subgroup differences, P = 0.003). Year of publication and methodological quality did not influence these findings; however, a publication bias may be present as the test of asymmetry was significant (P = 0.003). EN was associated with significant reduction in ICU LOS (weighted mean difference [WMD] -0.80, 95 % CI −1.23, −0.37, P = 0.0003, I2 = 0 %) while no significant differences in hospital LOS and mechanical ventilation were observed.ConclusionsIn critically ill patients, the use of EN as compared to PN has no effect on overall mortality but decreases infectious complications and ICU LOS. This may be explained by the benefit of reduced macronutrient intake rather than the enteral route itself.Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-016-1298-1) contains supplementary material, which is available to authorized users.

In ICUs with low baseline nutritional adequacy, use of the enhanced protein-energy provision via the enteral route feeding protocol is safe and results in modest but statistically significant increases in protein and calorie intake.

IntroductionThe potential benefit of parenteral glutamine (GLN) supplementation has been one of the most commonly studied nutritional interventions in the critical care setting. The aim of this systematic review was to incorporate recent trials of traditional parenteral GLN supplementation in critical illness with previously existing data.MethodsAll randomized controlled trials of parenterally administered GLN in critically ill patients conducted from 1997 to 2013 were identified. Studies of enteral GLN only or combined enteral/parenteral GLN were excluded. Methodological quality of studies was scored and data was abstracted by independent reviewers.ResultsA total of 26 studies involving 2,484 patients examining only parenteral GLN supplementation of nutrition support were identified in ICU patients. Parenteral GLN supplementation was associated with a trend towards a reduction of overall mortality (relative risk (RR) 0.88, 95% confidence interval (CI) 0.75, 1.03, P = 0.10) and a significant reduction in hospital mortality (RR 0.68, 95% CI 0.51, 0.90, P = 0.008). In addition, parenteral GLN was associated with a strong trend towards a reduction in infectious complications (RR 0.86, 95% CI 0.73, 1.02, P = 0.09) and ICU length of stay (LOS) (WMD –1.91, (95% CI -4.10, 0.28, P = 0.09) and significant reduction in hospital LOS (WMD -2.56, 95% CI -4.71, -0.42, P = 0.02). In the subset of studies examining patients receiving parenteral nutrition (PN), parenteral GLN supplementation was associated with a trend towards reduced overall mortality (RR 0.84, 95% CI 0.71, 1.01, P = 0.07).ConclusionsParenteral GLN supplementation given in conjunction with nutrition support continues to be associated with a significant reduction in hospital mortality and hospital LOS. Parenteral GLN supplementation as a component of nutrition support should continue to be considered to improve outcomes in critically ill patients.

Neuromuscular blockade in severely head-injured patients decreases energy expenditure to basal levels, independent of morphine use, body temperature, and feeding. Levels of hypermetabolism in both the head-injured and trauma groups were relatively low, at 19% and 5% above predicted values, respectively. This study provides useful information for the management of nutrition support in severely traumatized patients.