To determine the effect on gastric contents of unlimited clear fluid ingestion by children up to two and a half hours and then up to two hours before elective surgery, 228 healthy children (ages two to twelve years) were prospectively studied. During Phase I of this study subjects ingested unrestricted volumes and types of clear fluids up to three hours (control group) or two and a half hours before surgery. After establishment of adequate anaesthesia, gastric fluids were aspirated via an orogastric tube. Gastric volume was measured with a syringe and gastric pH was determined. After determining that there was no adverse effect associated with reducing a clear fluid fast to two and a half hours, Phase II of the study was begun. The methods for Phase II were unchanged except that unlimited clear fluids were permitted up to three hours (control group) or two hours preoperatively. In both Phase I and II, gastric volume and gastric pH were unaffected by reducing the fast to less than three hours. It is concluded that ingestion of unlimited clear fluids up to two hours before elective surgery does not affect gastric contents of healthy children.

Patients are required to abstain from food and drink before surgery. In younger patients the resulting fast of 6 to 18 hours leads to thirsty, hungry and irritable children. 1.2 In order to minimize these discomforts, the optimum length for this fast must be established.Previous studies have demonstrated the safety and efficacy of administering specific volumes (2-10 ml. kg-i) and types (water, apple juice, five per cent dextrose water and 20 per cent Poly-Joule) of clear fluids to children two to three hours before surgery. 1-5 This study of healthy children compared the effect of an overnight fast with the effect of permitting unlimited clear fluids up to three hours before surgery on gastric fluid volume and pH. MethodsThis study was approved by the Hospital Ethics Committee and parental consent was obtained. Patients were excluded from the study if there was a history of gastrointestinal disease or if the patient was receiving medication known to affect gastric contents.One hundred and twenty-one healthy children aged 2-12 yr scheduled for elective surgery were randomly assigned to one of two groups. Children in Group A fasted from midnight. Children in Group B did not consume solid food on the day of their operation but were instructed to ingest unlimited volumes and types of clear fluids up to three hours before their scheduled surgery. For the purpose of this study clear fluids were defined as aqueous solutions, which are liquids at 37 ~ C. 6'7 Non-clear fluids, suspensions and emulsions, such as milk and most broths, were not permitted. Parents or nursing staff were asked to monitor accurately the amount of fluid ingested on the day of surgery.

We have studied the effect of ingestion of unlimited clear fluids by adolescents up to 3 h before anaesthesia to determine the effect this fluid ingestion would have on thirst, hunger and gastric contents at induction of anaesthesia. We studied prospectively 152 adolescents (ages 13-19 yr) undergoing elective surgery. Fifty percent of the patients had nothing by mouth after midnight. The other 50% were instructed to ingest unlimited clear fluids up to 3h before surgery. On arrival in the operating room, subjects were asked to assess thirst and hunger with a linear analogue scale of 0-10 (0 corresponding to no thirst or no hunger). After induction of anaesthesia, gastric contents were aspirated via a 16-French gauge orogastric tube. Gastric fluid volume (GV) was measured with a syringe and gastric pH (GpH) was assessed with Merck pH strips. GV, GpH and subject hunger were unaffected by ingestion of clear fluids. Subject thirst was reduced by clear fluids. It is concluded that unlimited clear fluid ingestion by healthy adolescents up to 3 h before operation decreases thirst and does not affect gastric contents.