Medical Journal of The Islamic Republic of Iran (MJIRI)

    Background: Increased protein intake is recommended for critically ill patients to prevent muscle breakdown and weakness. In this study, researchers compared protein delivery and muscle loss in mechanically ventilated intensive care unit (ICU) patients receiving high-protein enteral nutrition with those receiving standard care.
   Methods: This was a randomized, open-label, controlled clinical trial conducted at a mixed medical-surgical ICU. Mechanically ventilated adult patients (age ≥18 years) who required enteral nutrition (EN) for at least 72 hours were randomized to receive either the intervention (target protein delivery of 1.5 g/kg per day) or standard care (provide 1.0 g/kg/day protein). Ultrasonography measured the muscle thickness of the biceps brachii for assessment at baseline and days 3, 6, 9, 12, 15, 18, and 21 after randomization. Adequacy of nutritional support was determined by measuring nitrogen balance (NB) at days 3 and 5 after the intervention. Descriptive statistics were used to summarize patient characteristics, and baseline demographic and clinical data were compared between groups using chi-square tests and independent samples t tests. Generalized estimating equations (GEE) were employed to analyze longitudinal data, assessing the effects of time, treatment group, and diabetes mellitus on muscle outcomes, while addressing missing data with the Last Observation Carried Forward method. The primary outcomes, changes in muscle mass and mid-upper arm circumference, were compared between treatment groups using independent samples t tests and further evaluated with analysis of covariance models adjusted for covariates.
   Results: A total of 100 patients were studied in high protein (n = 50) and low protein (n = 50) groups. The mean muscle loss in the high-protein group [mean, -0.06 [95% CI, -0.09 to -0.02)] was significantly lower than the low-protein group [mean, -0.27 [95% CI, -0.34 to -0.22)] (P < 0.001). Patients in the high-protein group exhibited significantly higher nitrogen balance values compared to those in the low-protein group on day 3 (P < 0.001) and day 5 (P < 0.001).
   Conclusion: This study showed that high-protein EN might have positive effects to attenuate the muscle loss and improve the nutritional status of mechanically ventilated ICU admitted patients.