There was no evidence to suggest a shortened fluid fast results in an increased risk of aspiration, regurgitation or related morbidity compared with the standard 'nil by mouth from midnight' fasting policy. Permitting patients to drink water preoperatively resulted in significantly lower gastric volumes. Clinicians should be encouraged to appraise this evidence for themselves and when necessary adjust any remaining standard fasting policies (nil-by-mouth from midnight) for patients that are not considered 'at-risk' during anaesthesia.
Effect of the preoperative administration of water on gastric volume and pH.
Since the preoperative administration of water might promote gastric emptying and dilute the remaining gastric contents, 50 patients were investigated before elective surgery. One group was given water 100 ml 2 h before operation; the other group was fasted as usual. Volume and pH of gastric contents were measured immediately after the induction of anaesthesia. Although the mean gastric residue was less in those patients who were given water, the differences were not statistically significant. There was no difference in gastric pH between the two groups.