Effect of High Protein Normocaloric Nutrition on Skeletal Muscle Wasting in Critically Ill Mechanically Ventilated Patients: A Randomized Double-blind Study

Background and aims: Muscle wasting in critically ill patients is associated with poor outcomes. During intensive care unit (ICU) stay, delivering appropriate nutritional support helps minimize muscle loss. We sought to evaluate the impact of high-dose protein on muscle thickness and cross-sectional area (CSA), as well as to track changes in muscle echogenicity and pennation angle (PA) using bedside ultrasound in this population. Patients and methods: We conducted a randomized, prospective, double-blind trial in which 30 patients mechanically ventilated for more than 48 hours and receiving enteral feed were enrolled. Patients were divided into two groups, and all patients received enteral feeds with total calories of about 25 kcal/kg/day. In the high-protein feed (HPF) group, patients were targeted to receive 1.5 gm/kg/day of protein, whereas in the standard feed (SF) group, patients received 1 gm/kg/day of protein. After ICU admission, muscle thickness, CSA, echogenicity, and PA were measured in all mechanically ventilated patients on days 1, 3, 5, and 7 using bedside ultrasound. The right lower limb vastus lateralis (VL) and the medial head of the gastrocnemius were investigated. Results: We found a progressive decrease in muscle mass from day 1 to day 7 in all patients. Our study showed that muscle thickness and CSA were significantly higher in the HPF group than the SF group over 7 days, whereas muscle echogenicity and PA changes were not statistically significant. Conclusion: High-protein feeds prevent muscle wasting in critically ill patients compared to patients receiving SFs during the first week of ICU stay. The qualitative muscle parameters, like muscle echogenicity and PA changes, were not significant.