Nutrition support in the intensive care unit: an evolving science.

Recent investigations of nutrition support in the intensive care unit (ICU) have revived discussion of optimal strategies for tight glucose control and the administration of total parenteral nutrition. Mode, timing, and adequacy of nutritional support affect glycemic control and outcomes in critically ill patients. The delivery of correctly formulated and safely administered nutritional and metabolic support is a matter of life or death in surgical and critical care units. High-quality research, adequately powered to detect differences in clinically meaningful outcomes, is needed to inform the delivery of nutrition support and serve as the foundation for future clinical trials. These are issues that will need to be addressed in the months and years ahead. Today, the field is in the midst of challenges and change, and though much has been accomplished, much remains to be done. The last 30 years have seen radical changes in the rates of severe obesity, metabolic syndrome, and weight loss surgery. Obese patients heighten surgical risk and require extra caution by ICU nutrition support specialists. This commentary will address the direction of nutrition support services by covering the history, progress, and potential of the field. It will review parenteral nutrition from its inception to its current standing in ICU patient care and discuss the future role of parenteral nutrition in a rapidly changing and increasingly diverse population.