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.

This study is a prospective observational cohort study which will be conducted in 2 parts including preoperative and intraoperative periods. * Preoperative period, patients' demographic information will be collected along with NPO history including times, type ,amount of preoperative fluid/ food intake and patients' anxiety score. * Intraoperatively, at the beginning of EGD procedure, total volume of intragastric content(ml) and gastric acidity will be measured. We plan to offer participation to all patients or parents of patients' ages 0-17 years who are scheduled for EGD at GPU, BCH Longwood campus and are fluent in English. A brochure describing our study in English will be given to patients or their families on the day of surgery. If the patient or family agrees to participate in this study, the study will be provided in the GPU theaters.

Inclusion Criteria:

\- All patients who aged 0-17 years scheduled for EGD procedure.

Exclusion Criteria:

\- Patients who required emergency EGD procedures and patients with active upper GI bleeding.