RESUMEN
There is no information on the effects of variable amounts of water given less than 2 hour before induction of general anesthesia, although most patients receive oral premedication at that time. We have studied the effect of the volume of water which should accompany diazepam 0.2 mg/kg oral premedication given 90 minutes before induction of anesthesia in 75 patients undergoing elective laparoscopic cholecystectomy. The patients, ASA physical status I, randomly assigned to one of five groups. Fifteen patients were received no premedication (group A), 15 patients 50 ml (group B), 15 patients 100 ml (group C), 15 patients 150 ml (group D), and 15 patients 200 ml of water (group E). Immediately following induction of anesthesia the gastric fluid was obtained by suction on a nasogastric tube and its volume and pH were measured. Gastric fluid volume showed no statistically significant differences among the groups. Values for pH among the groups were also similar. All premedication groups reported a reduction in thirst after water intake, while only group D reported significant anxiolysis. We conclude that 150 ml is the ideal amount of water given with oral prnedication 90 minutes before general anesthesia.