Preoperative nutrition therapy - novel developments

Abstract

Elective surgery has until recently been performed in the overnight fasted state in order to reduce the risk of aspiration of gastric content during the induction of anaesthesia. However, in order to increase the preoperative well-being of surgical patients, most western countries have changed their routines during the last 10-15 years, allowing intake of clear fluids up to 2 hours before anaesthesia in most patients. Animal studies have demonstrated that undergoing different situations of stress in the fed state is superior to stress in the short-term fasted state. To evaluate whether this also applies to surgical patients, a series of clinical studies have been performed, in which the metabolic, subjective, and clinical outcome has been compared in patients randomised to preoperative carbohydrate loading or not. These studies include the development of a carbohydrate-rich drink, which has been tested and shown to be safe in the perioperative situation. The results from these studies, reviewed in this article, suggest that fasting is not the optimal way to prepare for surgical stress, and that preoperative carbohydrate loading could have metabolic as well as clinical benefits. Keywords: carbohydrates, insulin resistance, preoperative fasting, surgery, well-being