Association of protein intake with the outcomes of critically ill patients: a post hoc analysis of the PermiT trial

• Published in: The American journal of clinical nutrition 2018-11, Vol.108 (5), p.988-996
• Main Authors: Arabi, Y M, Al-Dorzi, H M, Mehta, S, Tamim, H M, Haddad, S H, Jones, G, McIntyre, L, Solaiman, O, Sakkijha, M H, Sadat, M, Afesh, L, Kumar, A, Bagshaw, S M, Aldawood, A S
• Format: Article
• Language: English
• Subjects: Adult; Aged; Biomarkers; Biomarkers - metabolism; calories; Clinical trials; Critical Care - methods; critical illness; Critical Illness - mortality; Critical Illness - therapy; Diet; Dietary Proteins - administration & dosage; Dietary Proteins - therapeutic use; Energy Intake; Enteral feeding; Enteral Nutrition; Excretion; Feeding; Female; Humans; Male; Middle Aged; Mortality; Nitrogen; Nitrogen - metabolism; Nitrogen balance; NUTRIC score; Nutritional Requirements; Patients; Prealbumin - metabolism; protein catabolism; Proteins; Transferrin; Transferrin - metabolism; Urea; Urea - metabolism; Urine
• ISSN: 0002-9165; 1938-3207
• DOI: 10.1093/ajcn/nqy189

The optimal amount of protein intake in critically ill patients is uncertain. In this post hoc analysis of the PermiT (Permissive Underfeeding vs. Target Enteral Feeding in Adult Critically Ill Patients) trial, we tested the hypothesis that higher total protein intake was associated with lower 90-d mortality and improved protein biomarkers in critically ill patients. In this post hoc analysis of the PermiT trial, we included patients who received enteral feeding for ≥3 consecutive days. Using the median protein intake of the cohort as a cutoff, patients were categorized into 2 groups: a higher-protein group (>0.80 g · kg–1 · d–1) and a lower-protein group (≤0.80 g · kg–1 · d–1). We developed a propensity score for receiving higher protein. Primary outcome was 90-d mortality. We also compared serial values of prealbumin, transferrin, 24-h urinary nitrogen, and 24-h nitrogen balance on days 1, 7, and 14. Among the 729 patients included in this analysis, the average protein intake was 0.8 ± 0.3 g · kg–1 · d–1 [1.0 ± 0.2 g · kg–1 · d–1 in the higher-protein group (n = 365) and 0.6 ± 0.2 g · kg–1 · d–1 in the lower-protein group (n = 364); P