The Future of Critical Care Nutrition Therapy

At present, we are in a "revival" period in clinical nutrition in critical care, especially in the area of "pharmaconutrition." Adequate nutrition may hinge not only on how many calories are provided but also on the ability to provide key pharmacologically acting nutrients. Traditionally, nutrition has been viewed as vital for metabolism, growth, and repair. But, it is now known that some nutrients, when given in therapeutic doses, appear to serve as pharmacologic agents to improve clinically relevant outcomes. Thus, larger therapeutic doses of specific nutrients may be required to replace acute deficiencies brought on by specific injury or disease states. Recent data also imply that the number of calories and protein delivered early in the intensive care unit (ICU) stay has a significant effect on outcome in at-risk patients. It is thought that the future of ICU nutrition will involve administering early nutrition preferentially via the enteral route. Supplementation by parenteral route may be used in at-risk patients when adequate enteral calories cannot be provided. Specific pharmaconutrients can also be administered as separate components, much like a drug is given. Large multicenter trials are planned or are underway to test these hypotheses. The use of basic clinical pharmacology, molecular biology, and clinical research principles in the study of nutritional therapy will lead to answers on how to administer the right nutrients, in the right amounts, at the right time to critically ill patients.