COMPARISON OF THE EFFECT OF 2 DOSE SCHEDULES OF ORAL OMEPRAZOLE WITH ORAL RANITIDINE ON GASTRIC ASPIRATE PH AND VOLUME IN PATIENTS UNDERGOING ELECTIVE SURGERY

We have compared gastric aspirate pH and volume at induction of anaest hesia in 222 patients who had received either omeprazole or ranitidine before elective operations. Omeprazole was given orally either as 40 mg on the evening before and 40 mg on the morning of surgery or as 80 mg on the morning of surgery. Ranitidine 150 mg was given orally on th e evening before surgery and 2 h before anaesthesia. Treatment success was defined as aspirate pH greater than or equal to 2.5 and volume < 25 ml at induction of anaesthesia. Treatment was successful in 84% (95 % confidence interval (CI) 73-91%) of patients in the omeprazole 40 40 mg group, 84% (95% CI 73-91%) in the ranitidine group and 73% (95% CI 61-83%) in the omeprazole 80 mg group. There were no statistically significant differences between the groups. Twelve patients in the ome prazole 80 mg group had gastric pH < 2.5 and four had volume > 25 ml. Only three patients had a gastric pH < 2.5 in the omeprazole 40 + 40 m g group and none had volume > 25 ml, which compared well with the rani tidine group. Omeprazole, given as 40 mg in the evening and 40 mg on t he morning of operation, has a potential role for use in patients at r isk for aspiration during general anaesthesia.