Management of perioperative nutrition support.

PURPOSE OF REVIEW Perioperative nutrition has been extensively studied, but numerous questions remain unanswered. This review focuses on new developments in nutrient delivery in the immediate perioperative period. Issues specifically addressed include which patients are most likely to benefit from perioperative nutritional supplementation, and the optimal route, timing, and quantity of nutrient delivery. RECENT FINDINGS Visceral proteins, particularly albumin, play an important role in nutritional and perioperative risk assessment. Although the recommendation to use the enteral route for delivery of nutrition whenever possible is clear, the cautious introduction of enteral feeds in the labile group of patients with circulatory failure is essential. Preoperative use of immune-modulating enteral formulas, preoperative carbohydrate loading, and the concept of early enteral feeding are important developments. Supplementary arginine, glutamine, and omega-3 fats play a potential role in nutritional management, as does 'permissive' hypocaloric feeding. SUMMARY The particulars of nutritional support for perioperative and critically ill patients remain controversial. Recent studies addressing specific issues in this diverse discipline perhaps raise more questions than are answered. However, each new contribution to the literature brings us closer to an understanding of optimal nutritional management in the metabolically stressed patient.