Optimizing energy and protein balance in the ICU.

PURPOSE OF REVIEW: Perhaps now more than ever, appropriate nutrition delivery in the ICU is a highly debated issue. Nutrition guidelines for ICU patients by European Society for Clinical Nutrition and Metabolism in Europe, The Canadian Nutrition Guidelines, and American Society for Parenteral and Enteral Nutrition in the USA continue to disagree about the need to feed early and how. Most ICU patients around the world appear to be poorly fed.

RECENT FINDINGS: Most studies have focussed on energy supply by enteral or parenteral nutrition. Some studies suggest that late initiation of energy supply could be beneficial. However, studies still not provide the answer as to when and how to feed the patient. A few studies have now also focussed on protein supply. Studies agree on the importance of adequate protein supply, 1.2-2.0 g/kg, for outcome. In fact, early protein supply might be more important than energy supply; however, limited data are available.

SUMMARY: These findings implicate that optimization of protein balance in ICU patients as well as energy balance will improve outcome. In clinical practice, protein targets for patients should be set and achieved. More research is needed to define when and how to best feed the ICU patient.