Beta-hydroxy-beta-methylbutyrate supplementation and functional outcomes in multitrauma patients: A pilot randomized controlled trial.

BACKGROUND: Beta-hydroxy-beta-methylbutyrate (HMB) is a nutrition supplement that may attenuate muscle wasting from critical illness. This trial aimed to determine feasibility of administering a blinded nutrition supplement in the intensive care unit (ICU) and continuing it after ICU discharge. METHODS: Single-center, parallel-group, blinded, placebo-controlled, randomized feasibility trial. After traumatic injury necessitating admission to ICU, participants were randomized to receive an enteral study supplement of 3 g of HMB (intervention) or placebo daily for 28 days or until hospital discharge. Primary outcome was feasibility of administering the study supplement, quantified as protocol adherence. Secondary outcomes included change in quadriceps muscle thickness, measured weekly until day 28 or hospital discharge by using ultrasound and analyzed by using a linear mixed model. RESULTS: Fifty randomized participants (intervention, n = 26; placebo, n = 24) showed comparable baseline characteristics. Participants received 862 (84.3%) of the 1022 prescribed supplements during hospitalization with 543 (62.8%) delivered via an enteral feeding tube. The median (IQR) number of study supplements successfully administered per participant was 19.5 (13.0-24.0) in the intervention group and 16.5 (8.5-23.5) in the placebo group. Marked loss of quadriceps muscle thickness occurred in both groups, with the point estimate favoring attenuated muscle loss with the intervention, albeit with wide CIs (mean intervention difference after 28 days, 0.26 cm [95% CI, -0.13 to 0.64]). CONCLUSION: A blinded, placebo-controlled, randomized clinical trial of daily enteral HMB supplementation for up to 28 days in hospital is feasible. Any effect of HMB supplementation to attenuate muscle wasting after traumatic injury remains uncertain.

Protein supplementation in critical illness: why, when and how?

PURPOSE OF REVIEW: In critically ill patients, optimal protein provision remains a challenge given the wide range in recommended protein delivery in international guidelines and the lack of robust, high quality evidence. As patients are confronted with poor functional outcomes after admission, often attributed to muscle wasting and persisting for multiple years, there is a pressing need for optimal nutritional strategies in the ICU, particularly including protein. This review will discuss the recent literature with regard to purpose, timing and mode of protein delivery. RECENT FINDINGS: Recent studies on the effect of dose and timing of protein on clinical and functional outcomes are largely observational in nature and the protein delivery considered as "high" still often only nears the lower end of current recommendations. The majority of trials observed no effect of protein supplementation on mortality, muscle strength or function, though some report attenuation of muscle volume loss, especially when combined with muscle activation. There is no strong evidence that ICU patients should receive supplementation with any specific amino acids. SUMMARY: Though adequate protein provision is likely important, it is difficult to come to a uniform conclusion regarding dosing and timing due to conflicting results in mostly observational studies as well as different cut-off values for high, moderate and low protein intake. This topic is currently subject to large clinical trials.