Single-dose oral omeprazole for reduction of gastric residual acidity in adults for outpatient surgery

Acta Anaesthesiol Scand. 1992 Aug;36(6):513-5. doi: 10.1111/j.1399-6576.1992.tb03509.x.


Omeprazole is a substituted benzimidazole that causes dose-dependent intracellular inhibition of gastric acid secretion in humans. This double-blind study examined the effect of omeprazole in decreasing gastric acidity and gastric residual volume in outpatient adults. Unpremedicated outpatients, ASA I-III, 18 years or older (n = 17), were randomly assigned to receive omeprazole 80 mg, or placebo by mouth the night before scheduled elective outpatient surgery. The patients were fasted for 8 h prior to surgery. After the patient was anesthetized, an orogastric tube was inserted with proper placement verified by auscultation for gastric sounds. Gastric residual contents were withdrawn into a Luken's trap, and pH was then determined and gastric volume indexed to weight ( Data were analyzed by a t-test, with P less than 0.05 considered statistically significant. Patient characteristics of both groups were similar. There was a statistically significant difference between the two groups for pH (P = 0.02), but not between the two groups for gastric volume indexed to weight (P = 0.07).

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Administration, Oral
  • Adult
  • Ambulatory Surgical Procedures*
  • Depression, Chemical
  • Double-Blind Method
  • Gastric Acid / metabolism*
  • Humans
  • Omeprazole / administration & dosage*


  • Omeprazole