Bedside Ultrasound Assessment of Gastric Content and Volume. Validating a Mathematical Model Using Gastroscopic Examination

Patients undergoing gastroscopy will undergo two pre-procedure ultrasound scans of the stomach, once on arrival in the unit and on an empty stomach and a second time after consumption of a randomized amount of apple juice (0, 50, 100, 200, 300 or 400 mL). Immediately after ingestion and the second ultrasound scan, subjects will have their gastroscopy which will start by suctioning out the apple juice. Measurements of stomach fluid volume conducted by ultrasound will be compared to the actual volume removed during the gastroscopy procedure.