- To understand how to feed the surgical patient and understand the indications for preoperative and postoperative enteral or parenteral nutrition
Surgery involves a deliberate injury to the body inflicted for the overall benefit of the patient. The surgical insult results in several responses that cause a change in metabolism towards catabolism. Recovery from surgery requires a reversal of the trauma-induced catabolism towards anabolism. There are many ways by which the catabolic responses can be minimized and anabolism supported. Nutrition, the supply of energy and protein, represents an essential part of the perioperative treatment.
It is important to understand that for the majority of patients undergoing surgery, the nutritional treatment stimulates faster recovery. Most of these patients can eat and should be given oral food. The target of nutritional treatment should be to optimise fluid intake and ensure sufficient energy and protein intake orally.
A much smaller group of surgical patients are malnourished. These patients have a higher risk of mortality, complications, prolonged hospital stay and delayed rehabilitation and convalescence. Although some early studies of perioperative nutritional support were conflicting, over the last twenty years a succession of studies have begun to define those groups of patients who benefit, particularly those with prior malnutrition.
Because of the risks associated with malnutrition and surgery, all patients about to undergo surgery should be screened and assessed for nutritional status. Those with malnutrition should be considered for perioperative nutritional support. It is useful to consider the problem in three phases pre-, per- and postoperative.