Effect of oral omeprazole on intragastric pH and volume in women undergoing elective caesarean section

We have studied in obstetric patients the efficacy of omeprazole in increasing intragastric pH to more than 2.5 and reducing volume to less than 25 ml. Omeprazole 40 mg was given orally the night before and again on the morning of surgery to 30 Asian women scheduled to undergo elective Caesarean section. After induction of anaesthesia, a gastric tube was inserted and intragastric contents aspirated. Volume and pH were recorded and measurements were repeated on completion of surgery. The median (range) volume was 2 (1-13) ml before surgery and 4 (0-14) ml at the end of surgery. There was insufficient volume to measure pH in all patients. The median (range) pH was 6.7 (4.6-7.4) before surgery in 20 patients and 6.6 (4.6-7.8) at the end of surgery in 28 patients. No adverse drug reactions were noted in mothers or neonates. Omeprazole 40 mg orally twice before elective Caesarean section appeared to be effective in reducing intragastric volume and acidity to acceptable values.