Protein Delivery in the Intensive Care Unit: Optimal or Suboptimal?

Emerging evidence suggests that exogenous protein/amino acid supplementation has the potential to improve the recovery of critically ill patients. After a careful review of the published evidence, experts have concluded that critically ill patients should receive up to 2.0-2.5 g/kg/d of protein. Despite this, however, recent review of current International Nutrition Survey data suggests that protein in critically ill patients is underprescribed and grossly underdelivered. Furthermore, the survey suggests that most of protein administration comes from enteral nutrition (EN) despite the availability of products and protocols that enhance the delivery of protein/amino acids in the intensive care unit (ICU) setting. While future research clarifies the dose, timing, and composition for exogenous protein administration, as well as identification of patients who will benefit the most, ongoing process improvement initiatives should target a concerted effort to increase protein intake in the critically ill. This assertion follows from the notion that current patients are possibly being harmed while we wait for confirmatory evidence. Further research should also develop better tools to enable bedside practitioners to monitor optimal or adequate protein intake for individual patients. Finally, exploring the effect of combining adequate protein delivery with early mobility and/or resistance exercise in the ICU setting has the greatest potential for improving the functional outcomes of survivors of critical illness and warrants further study.