The North American Surgical Nutrition Summit was convened September 21–23, 2012, in Phoenix, Arizona. Experts from across North America and Europe were invited to participate based on expertise in the areas of general surgery, acute care surgery, oncologic surgery, and burns. Other attendees were asked to attend based on expertise in guidelines for critical care nutrition and experience with state and national surgical database systems. The focus of the summit was on nutrition therapy of the adult patient anticipating major elective surgery.
The existence of malnutrition preoperatively or the deterioration of nutrition status through the perioperative period is a well-recognized factor increasing postoperative complications and hospital length of stay. But unlike protocols to provide perioperative antibiotics, surgical site skin preparations, intraoperative patient warming, and prophylaxis for thromboembolic disease, little attention has been paid to standardizing nutrition management. Although the stress response evolved to confer improved chances of survival following injury, in modern surgical practice, the stress response can be detrimental. The surgical insult is associated with hyper-inflammation, oxidative stress, immune impairment, and insulin resistance, which expose patients to subsequent risk of infection. Factors that contribute to nutrition risk include the patient’s pre-existing nutrition status, the severity of the surgical insult, and the likelihood for anatomic alterations postoperatively Perioperative administration of a pharmaconutrition formula containing arginine, fish oil, and nucleotides has been shown to reduce infection, other complications, and hospital length of stay in patients undergoing major upper or lower gastrointestinal (GI) surgeries, regardless of pre-existing nutrition status. A synergistic effect may exist between arginine and fish oils, and therefore a combination of the 2 agents should be used. Single-substrate administration does not affect clinical outcome. Timing of preoperative delivery is optimized by starting 5–7 days prior to surgery (500–1000 mL/d) and continuing into the postoperative period. Since impairment of host defence systems occurs immediately after surgery, immunonutrients should be given prior to surgery to metabolically prepare the cells for surgical stress. Substrates provided only in the first few days after surgery may not be sufficient to reach adequate tissue and plasma concentrations Enhanced Recovery After Surgery (ERAS) supports a standardized protocol for perioperative care, one aspect of which includes preoperative carbohydrate loading.27 Following ERAS principles has been shown to decrease complications and hospital length of stay, primarily in colorectal surgery. Carbohydrate loading for the surgery patient, similar to the marathon runner, maximizes glycogen stores to support the need for gluconeogenic substrates through surgery (rather than drawing on lean body tissue). Provision of a carbohydrate drink reduces insulin resistance and tissue glycosylation through surgery, helps postoperative glucose control, and enhances return of bowel function. The patient should drink 800 mL of a 12.5% carbohydrate drink the night before surgery and 400 mL the next morning 2 hours prior to induction of anesthesia for surgery, unless contraindicated.27 The guidelines put forth by the American Society of Anesthesiologists support the consumption of clear liquids up to 2 hours prior to surgery.