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.