Effect of preoperative oral use of erythromycin and nizatidine on gastric pH and volume.

This randomized controlled trial examined the effects of preoperative oral erythromycin or nizatidine on gastric pH and volume. Sixty patients, ASA 1 and 2 status scheduled for elective surgery were studied. All subjects received oral study medication with 10 ml of water 60 minutes prior to surgery. Patients in Group 1 (n=20) were given erythromycin 200 mg, in Group 2 (n=20) nizatidine 300 mg, and in Group 3 (n=20) placebo capsule. A nasogastric tube was inserted immediately after anaesthesia induction. Gastric content was aspirated, and volume and pH recorded. pH values determined in Group 1 were 5.6+/-1.87; in Group 2, 5.65+/-1.92 and in Group 3, 3.5+/-1.93. There was no statistical difference between Groups 1 and 2, but there was a statistically significant difference between Group 3 and Groups 1 and 2 (P<0.001). The volume of gastric content was 10.25+/-6.65 ml in Group 1, 10.3+/-6.29 ml in Group 2 and 20.25+/-16.72 ml in Group 3. Again, there was no statistical difference between Groups 1 and 2, but there was a statistically significant difference between Group 3 and Groups 1 and 2 (P<0.05). The proportion of patients considered "at risk" of significant lung injury should aspiration occur was 10% of Group 1, 5% of Group 2 and 20% of Group 3 (not statistically different). We conclude that oral erythromycin and nizatidine given one hour prior to surgery are effective in reducing gastric pH and volume.