Algorithms for Nutritional Therapy in Surgical Patients

Traditional concepts for nutritional therapy in surgical patients focused on peri-and postoperative nutrient supply. However, there is significant evidence from numerous multi-center studies that a preoperative nutritional conditioning which is supplemental to peri-and postoperative nutrition may further improve postoperative morbidity and convalescence. For preoperative nutritional therapy it is essential to establish an effective nutritional screening (such as subjective global assessment or nutritional risk screening 2002), and to supply an appropriate mix of substrates. Furthermore, one should avoid prolonged preoperative fasting periods thereby reducing the perioperative stress reaction. Beyond preoperative nutritional therapy also traditional postoperative nutritional concepts have been modified recently. These modifications also involve feeding of patients with intestinal anastomoses who are more tolerant to oral/enteral food than previously thought. Part of these new postoperative strategies is the early insertion of percutaneous catheter jejunostomies or of nasogastric or transpyloric feeding tubes. The latter are particularly efficient if the patient is malnourished or has undergone an operation at the upper gastrointestinal tract. If it is not possible to administer a sufficient amount of calories via the oral/enteral route, the patient has to be started on a supplementary, partial parenteral nutrition. Exclusive, complete parenteral nutrition is reserved for patients whose intestinal passage or function clearly fails (ileus, diarrhea, vomiting), or who hare severely malnourished. Another important determinant for patient convalescence is the continuation and modification of nutritional regimens beyond the acute phase also after discharge.