Effect of intragastric pH on control of peptic ulcer bleeding

Background: We have performed series studies to investigate the effect of i ntragastric pH on control of peptic ulcer bleeding. In laboratory and anima l studies, both platelet aggregation and gastric mucosal bleeding time were shown to be extremely sensitive to different pH levels. Platelet aggregati on decreased significantly at pH greater than or equal to 6.8 and gastric m ucosal bleeding time fell significantly at pH greater than or equal to 6.4. In a prospective clinical trial, primed infusions of different dosages of omeprazole (8 or 4 mg/h) after a bolus (40 mg) produced consistently high i ntragastric pH values in patients with bleeding duodenal ulcer. These resul ts were not significantly different from that obtained from omeprazole 40 m g bolus treatment every 12 h (P > 0.05). However, primed injection with cim etidine (800 mg/12 h) was less effective (P < 0.05). Methods: In a retrospective analysis, 303 patients with bleeding peptic ulc er who were treated with cimetidine and 326 patients who were treated with omeprazole were compared. Results: The emergency surgery (4.91%) and mortality rates (1.84%) in the o meprazole group were not significantly different (P > 0.05) from those (7.2 8 and 1.99%) in the cimetidine group. However, the standardized emergency s urgery rate of the omeprazole group (3.28%) was significantly lower than th at (9.28%) of the cimetidine group (P < 0.05). Conclusion: We conclude that increased intragastric pH to at least 6.4 with omeprazole is helpful in controlling peptic ulcer bleeding. Chinese patien ts require a lower dose of omeprazole than their Western counterparts to co ntrol ulcer bleeding. (C) 2000 Blackwell Science Asia Pty Ltd.