Abstract
The patients' condition prior to surgery is of major importance for clinical outcome. It is believed nowadays that artificial nutrition in the form of a preoperative drink may improve postoperative outcome. Until now, a clear overview concerning the effects of preoperative supplementation on patients' well-being has been lacking. The aim of this review is to summarize the results of randomized clinical trials investigating the effects of different preoperative supplements such as carbohydrate (CHO)-rich beverages, oral nutritional supplements (ONSs), immunonutrition and lemonades on clinical, metabolic and immunological parameters. We reviewed the relevant articles published between 1995 and 2012. Preoperative CHO-rich drinks appear to be safe, do not affect gastric emptying time and switch the fasted state to a fed state. Moreover, a significant reduction of postoperative insulin resistance, an improved well-being of the patient and prevention of surgery-induced immunodepression was found. For ONSs, beneficial effects were found according to muscle metabolism and strength, glucose storage and cost-effectiveness. Preoperative supplementation of immunonutrition resulted in improved immune function, restricted inflammatory response after surgery, prevention of organ damage, improved nutritional status with subsequently decreased postoperative complication rates and reduced length of hospital stay. Preoperative oral supplements have beneficial effects on many aspects of patient's well-being and recovery. Different supplements, preferably in combination with each other, can help to reduce postoperative complications after surgery and length of hospital stay. Nutritional support must not be overlooked when considering optimal surgical care.