Effect of NPO Time and Type of Food Intake on Preoperative Residual Gastric Content and pH

According to normal physiology, the longer fasting period allows food particles to pass stomach through small intestines to minimize intragastric content. The practice guidelines recommend 2-hour fasting period for clear fluid (including water, pulp-free juice and tea or coffee without milk), 4- hour fasting period for breast milk and 6-hour fasting period for non-human milk and solid food to reduce risks of pulmonary aspiration. As a result of longer fasting period, patients tend to experience preoperative dehydrated states and intraoperative hypotension. Patients' demographic data will be obtained from charts. Parents will be asked for type, volume of fluid/food intake and NPO time.

This study will be done at BCH's Gastroenterology Procedure Unit (GPU) theaters to measure actual intragastric volume and pH at the beginning esopagogastroduodenoscopy procedures. We hope to demonstrate the relationship between NPO time and actual intragastric volume which provide sufficient data of NPO time to ensure patient's safety.