Enteral protein supplementation in critically ill trauma and surgical patients: A single-center randomized clinical trial

BACKGROUND Critically ill trauma and surgical patients are highly catabolic, with expected high protein needs. However, there is uncertainty regarding the amount of protein required to optimize their outcomes. We conducted a single-center, randomized clinical trial to test the hypothesis that supplementing enteral protein intake would improve outcomes. METHODS Between November 15, 2016, and November 26, 2021, critically ill trauma and surgical patients were randomized either to a treatment arm aimed to deliver 2 g/kg/d of enteral protein or to standard nutritional care. Data were collected and subjects were followed until hospital discharge. Serum transthyretin concentration 14 to 21 days following intensive care unit admission and ventilator-free days were prespecified endpoints. RESULTS We randomized 500 subjects who were predominantly male (77%), suffered traumatic injuries (86%), and had a median age of 47 years. Those in the treatment arm received twice the amount of protein than those in the control arm (1.2 ± 0.65 g/kg/d vs. 0.6 ± 0.39 g/kg/d averaged over the first 7 days of hospitalization; p < 0.001). We observed no significant difference in mean transthyretin concentrations (difference of means, 0.8 mg/dL; 95% confidence interval, −1.3 to 2.8; p value = 0.46) or ventilator-free days (difference of means, −1.1; 95% confidence interval, −2.8 to 0.6; p value = 0.21). Participants receiving supplemental protein had higher blood urea nitrogen concentrations and were more likely to require reintubation. CONCLUSION In this clinical trial of critically ill trauma and surgical patients, protein supplementation did not improve outcomes but was associated with increased complications. LEVEL OF EVIDENCE Therapeutic/Care Management; Level II.