Medical high-protein nutrition therapy and loss of muscle mass in adult ICU patients: A randomized controlled trial

Abstract

Background & aims: The degradation of muscle mass and loss of functional proteins due to catabolism are associated with adverse outcomes in critically ill patients. While an adequate supply of protein within a medical nutrition concept is suggested to minimize proteolysis, the specificities on appropriate dosage and timing are still under debate. The current study aimed to evaluate the effect of two different quantities of protein as part of a standardized energetically controlled nutrition therapy for the preservation of muscle mass in the later phase of critical illness. Methods: A randomized controlled trial was conducted in 42 critically ill patients (age 65 ± 15; 12 females; SAPS 45 ± 11; TISS 20 ± 7; SOFA-score 7 ± 3). The subjects were randomly assigned to either the intervention (1.8 g protein/kg body weight [BW]/d) or standard (1.2 g protein/kg BW/d) group. Nutrient supply via enteral and/or parenteral nutrition was calculated based on the individual energy expenditure measured by indirect calorimetry and target protein content. Quadriceps muscle layer thickness (QMLT) was observed through sonography at inclusion, and during the follow-up period, two and four weeks after inclusion. The measurement points were fixed on two sides at the midpoint and two-thirds between the anterior superior iliac spine and top of the patella. The data were analyzed descriptively wherein chi-squared tests or unpaired two-samle t-tests checked group differences. Daily changes in muscle mass were estimated using a linear mixed model. All data are shown as the mean ± standard deviation (SD). Results: Actual protein intake reached 1.5 ± 0.5 g and 1.0 ± 0.5 g/kg BW/d in the intervention and standard group, respectively. Mean values of all measurements of QMLT at inclusion (day 13 ± 2 after ICU admission) were 13.5 ± 7.4 mm and 13.4 ± 7.1 mm in the intervention and standard group, respectively (P ¼ 0.967). In both the groups, QMLT decreased over time (P < 0.001), while the estimated mean values of daily QMLT changes were À0.15 ± 0.08 mm (intervention) and À0.28 ± 0.08 mm (standard) without significant between-group differences (intervention effect, P ¼ 0.368; time x intervention effect, P ¼ 0.242). Illness scores and clinical outcomes showed no group differences. Conclusion: In this single-center trial the increased amounts of protein (1.5 g vs. 1.0 g/kg BW/d) provided through medical nutrition therapy in the late phase of critical illness did not achieve a statistically significant impact on the loss of muscle mass in long-term immobilized ICU patients. Larger multi-center trials are needed to evaluate whether observed numerical differences in muscle mass could be a true finding, and will translate into improved clinical outcomes. Trial registration: German Clinical Trials Register (http://www.drks.de/), DRKS-ID: DRKS00013594.

The effect of higher versus lower protein delivery in critically ill patients: a systematic review and meta-analysis of randomized controlled trials

“…Nineteen RCTs totaling 1731 patients were included (sample size range: 14–474) [ 14 , 15 , 19 , 24 – 39 ]. Study characteristics are summarized in Table 2 .…”

“…Seven studies were conducted in Europe [ 15 , 25 , 27 , 30 , 33 , 35 , 37 ], four in Australia [ 24 , 26 , 32 , 39 ], four in Asia [ 14 , 19 , 28 , 36 ], two in North America [ 31 , 34 ], two in South America [ 29 , 38 ]. Nine studies included mixed medical and surgical population [ 14 , 24 – 27 , 29 , 30 , 32 , 39 ], four included patients with stroke or head injury [ 31 , 33 , 34 , 36 ], one included only medical [ 38 ], one included only surgical patients [ 15 ], and population studied (medical/surgical) was unclear in four studies [ 19 , 28 , 35 , 37 ]. One study included only overweight (BMI ≥ 25) [ 27 ], one included only obese (BMI ≥ 30) patients [ 35 ], and one included patients with non-oliguric acute renal failure requiring PN [ 37 ].…”

“…Sixteen studies started the intervention within 3 days of ICU admission. One study each started intervention within 5 days of acute stroke [ 36 ], 7–14 days after head injury [ 34 ] and after 10 days in the ICU [ 15 ]. The duration of intervention ranged 3 to 28 days.…”

“…Nineteen RCTs totaling 1731 patients were included (sample size range: 14-474) [14,15,19,[24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39]. Study characteristics are summarized in Table 2.…”

“…The systematic reviews by Davies and Fetterplace included studies that had significant differences in calories between groups, which may limit interpretation of results as the confounding effect of calories intake cannot be excluded [ 12 , 13 ]. Furthermore, since the publication of the last meta-analysis, several other RCTs have been published that were not included in these analyses [ 14 , 15 ].…”