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

Abstract

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.

Achieving Protein Targets in the ICU Using a Specialized High‐Protein Enteral Formula: A Quality Improvement Project

“…In our study, on average, patients were prescribed 133.7 g of protein/d or 1.9 g/kg/d, and 73%–85% of patients received at least 80% of the protein prescribed enterally on days 2–5. These results are in contrast to Heyland et al 2014 INS of 187 ICUs which found on average patients were prescribed 94 g protein/d or approximately 1.3 g/kg/d, and only 16.1% of patients received >80% of prescribed protein amounts . Although the protein targets in our study were higher (1.9 g/kg/d vs 1.2 g/kg/d or 1.5 g/kg/d), our findings are similar to 2 recent publications which both demonstrated that reaching protein targets is feasible .…”

“…In Taylor et al's UK audit of protein intakes, enteral feeding formulas with an NPC:N ratio of >100:1 failed to meet protein requirements in the majority of critically ill patients . In addition, it has been noted that despite the availability of modular protein supplements, these products contribute minimally to most patients’ overall protein intake . In our project, the majority of patients (84%) did not receive any additional protein supplements.…”

“…Critical illness can have a significant impact on protein needs . Providing adequate protein to critically ill patients may improve morbidity, mortality, and nitrogen accretion .…”

“…To meet the protein needs of tube fed patients, clinicians frequently use EN formulas that contain 18%–25% calories from protein and may add additional protein through use of supplemental enteral modular protein products or parenteral nutrition (PN). However, as Heyland et al observed from their INS data, despite the availability, modular proteins are used infrequently and contribute very little to most patients’ overall protein intake . A growing number of clinicians and medical nutrition experts recommend higher protein enteral formulas with lower nonprotein‐calorie nitrogen (NPC:N) ratios as part of the solution to help meet the protein needs of critically ill patients …”

Experimental and Outcome‐Based Approaches to Protein Requirements in the Intensive Care Unit

“…As protein delivery practices have been reviewed by Heyland et al, 24 we will focus on outcome studies here. As mentioned above, there is currently no randomized controlled trial (RCT) published with protein level randomized and adjusted for proper energy intake and long‐term clinical outcome.…”