1983 Volume 3 Issue 3 Pages 367-371
The effects of preanesthetic cimetidine on the pH and volume of gastric contents were studied in 65 patients scheduled for elective operation.
Oral cimetidine was given to 51 patients: 200mg to 20 patients (Group 1), and 400mg to 17 (Group 2), both 2 hours hours before induction of anesthesia, and 800mg every 6 hours on the day before operation and 200mg 2 hours before induction to 14 (Group 3). The remaining 14 patients served as controls.
Immediately after induction, gastric contents were aspirated via a double-lumen gastric tube and their pH and volume were measured and compared with the controls.
The gastric pH was significantly higher (p<0.01) in all treatment groups. The gastric volume was significantly lower in Group 2 (p<0.05) and Group 3 (p<0.01), but not in Group 1.
The percentages of those patients at high risk of pulmonary reaction following aspiration of gastric contents (i. e., with pH_??_2.5 and volume_??_25ml) were 50% for the controls, 20% for Group 1, 18% for Group 2, and 0% for Group 3.
These results demonstrate that premedication with oral cimetidine markedly increases gastric pH and decreases gastric volume, thereby reducing the incidence of pulmonary reaction in high risk surgical patients.
