DOI: 10.4103/njm.njm_7_23 ISSN: 1115-2613

A Comparison of the Effects of Preoperative Administration of Omeprazole and Ranitidine on Gastric Volume and pH in Patients Undergoing Elective Surgeries under General Anaesthesia

Adaobi Obianuju Amucheazi, Onyeka Ezinwanne Ohaka
  • General Medicine


Proton-pump inhibitors and histamine-2-receptor blockers act by reducing gastric volume and increasing gastric pH. These help to mitigate the effects of aspiration. However, the better of the two agents has not been established.


This prospective randomised, double-blind study was undertaken to compare the effects of omeprazole and ranitidine. Patients,

Materials and Methods:

One hundred and sixty American Society of Anaesthesiologist I and II adults scheduled for surgery under general anaesthesia were divided into two groups: Group R received 50 mg ranitidine and Group O 20 mg omeprazole. The drugs were given intravenously 2 h before the induction of anaesthesia. Gastric content was aspirated after induction and before extubation. The gastric volume and pH were measured and analysed.


The mean postintubation and preextubation gastric volumes were greater in Group R, whereas Group O exhibited an elevated mean postintubation and a significantly higher preextubation gastric pH.


The effect of omeprazole is superior to that of ranitidine as regards increasing gastric pH and reducing volume.

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