Residual Gastric Volume After the Ingestion of a Beverage Containing Carbohydrates Plus Whey Protein

Carbohydrate enriched-drinks has been used as preoperative treatment up to two hours before anesthesia. These drinks are safe and are not associated to bronchial aspiration during anesthesia. The addition of protein may be beneficial for metabolic preconditioning but there is a few data in literature testing these drinks for safety. The aim of the study will be to investigate the residual gastric volume (RGV) measured during the gastroscopy with abbreviation of fast to 2h with a carbohydrate plus whey protein enriched-drink.