One hour fast for liquids prior to endoscopy is safe, effective and results in minimum patient discomfort

Abstract

INTRODUCTION: Current guidelines for endoscopy advice at least 6-8 hours fasting for solids and at least 4 hours for liquids. This is claimed to ensure safety and a clear endoscopic view. However, prolonged fasting may result in patient discomfort. Also due to practical delays the fasting period for endoscopy may be much longer, thus causing even more discomfort to patients. Several anaesthesia societies now recommend a 2-h pre-operative fast for clear fluids and a 6-h fast for solids in most elective patients. A pilot study done by us showed the time for a clear liquid (tea) or water to empty from the stomach using real-time ultrasonography was one hour. AIMS: To determine whether a one-hour fast prior to endoscopy was safe, effective and resulted in less patient discomfort. METHODS: 63 patients referred for endoscopy, without alarm symptoms or clinically obvious motility problems, were recruited. Patients were given a standard meal 6 hours before endoscopy. They were then randomized to either nil by mouth for 6 hours (group A, n = 31) or allowed to take clear fluids up to one hour prior to endoscopy (group B, n = 32). Just prior to endoscopy patients indicated discomfort due to fasting on a visual analog scale (0-no discomfort to 10-severe discomfort). Investigators were blinded to the period of fasting. Presence of fluid in the gastric fundus was noted, and endoscopic vision was graded as good, average or poor. Patients were followed one week after the procedure for the presence of any late complications. RESULTS: Discomfort was significantly lower in group B than group A (median visual analog score 0.3 vs. 5.1; p < 0.0001, Wilcoxon two-sample test). Endoscopic vision was good in all 31 patients in group A and 30 in group B, and average in 2 patients in group B. None were graded as poor. Fluid in the gastric fundus was noted in 7 patients in group A and 10 in group B. There were no complications in either group. CONCLUSIONS: A one-hour fast for clear liquids seems safe and effective and has minimum discomfort for the patient. However, a larger study should be done before the current endoscopic guidelines are revised.