OMEPRAZOLE REDUCES PREOPERATIVE GASTRIC FLUID ACIDITY AND VOLUME IN CHILDREN

To explore the effects of oral omeprazole on preoperative gastric fluid pH and volume in children, 104 healthy in-patients aged 4-9 yr were randomly allocated to four groups (n = 26). Subjects in the Omeprazole-Omeprazole Group received two doses of omeprazole (20 mg per dose), those in the Placebo-Placebo Group, two doses of placebo, those in the Placebo-Omeprazole and Omeprazole-Placebo Groups, one dose each of the two preparations by mouth. For each treatment regimen, the first medication was administered at 9:00 p.m. on the night before surgery and the second at 5:30 a.m. on the morning of the day of surgery (three hours preoperatively). Children undergoing elective surgery were offered 10 ml.kg(-1) of apple juice three hours before induction of anaesthesia. After induction of anaesthesia and tracheal intubation, gastric fluid was aspirated through a large-bore, multiorifice orogastric cube and analyzed for pH and total fluid volume. The administration of omeprazole at bedtime before surgery increased gastric pH (3.3 +/- 1.3 vs 2.0 +/- 0.6, P < 0.05) in comparison with placebo, as did two doses of omeprazole (pH = 4.8 +/- 1.6, P < 0.05). A single dose of omeprazole administration on the morning of the day of surgery failed to increase gastric pH. There was a reduction in the number of children with a pH < 2.5 and a volume >0.4 ml.kg(-1) in the Omeprazole-Omeprazole and Omeprazole-Placebo Groups compared with the Placebo-Placebo or Placebo-Omeprazole Groups. Oral omeprazole 20 mg administered on the night prior to surgery will improve the gastric environment at the time of-induction of anaesthesia, thus reducing the potential risk of pneumonitis, should the aspiration of gastric contents occur following the induction of anaesthesia. These data also suggest that this drug, when administered in a single dose of approximately 1.0 mg.kg(-1) three hours before surgery, is ineffective in increasing gastric fluid pH to >2.4.