Assessment of residual gastric volume by ultrasound prior to upper endoscopy: a prospective cohort study.

Purpose: Pulmonary aspiration is an adverse event with high morbidity and mortality. Despite fasting for > 8 hr, some patients still have residual gastric volume and are thus at risk of aspiration. We aimed to determine the accuracy of gastric ultrasound in assessing residual gastric content in patients undergoing upper gastrointestinal endoscopy.