In modern surgical practice it is advisable to manage patients within an enhanced recovery protocol and thereby have them eating normal food within 1-3 days. Consequently, there is little room for routine perioperative artificial nutrition. Only a minority of patients may benefit from such
therapy. These are predominantly patients who are at risk of developing complications after surgery. The main goals of perioperative
nutritional support are to minimize negative
protein balance by avoiding
starvation, with the purpose of maintaining muscle, immune, and cognitive function and to enhance postoperative recovery. Several studies have demonstrated that 7-10 days of preoperative
parenteral nutrition improves postoperative outcome in patients with severe
undernutrition who cannot be adequately orally or enterally fed. Conversely, its use in well-nourished or mildly undernourished patients is associated with either no benefit or with increased morbidity. Postoperative
parenteral nutrition is recommended in patients who cannot meet their caloric requirements within 7-10 days orally or enterally. In patients who require postoperative artificial
nutrition, enteral feeding or a combination of enteral and supplementary
parenteral feeding is the first choice. The main consideration when administering fat and
carbohydrates in
parenteral nutrition is not to overfeed the patient. The commonly used formula of 25 kcal/kg ideal body weight furnishes an approximate estimate of daily energy expenditure and requirements. Under conditions of severe stress requirements may approach 30 kcal/kg ideal body weights. In those patients who are unable to be fed via the enteral route after surgery, and in whom total or near
total parenteral nutrition is required, a full range of
vitamins and
trace elements should be supplemented on a daily basis.