TECHNIQUE, INDICATIONS, AND CLINICAL USE OF AMBULATORY 24-HOUR GASTRIC PH MONITORING IN A SURGICAL PRACTICE

Background. Prolonged pH monitoring is used increasingly to assess alt erations of gastric luminal pH caused by gastroduodenal secretory and motor abnormalities. The clinical value of gastric pH monitoring, howe ver, has been debated. Methods. We obtained normal values for 24-hour ambulatory gastric pH monitoring in 50 healthy volunteers and evaluate d its clinical use by monitoring 285 consecutive patients with nonspec ific foregut symptoms and duodenal ulcers (n = 33), gastric ulcers (n = 21) antral gastritis (n = 123), or no mucosal injury (n = 108). Resu lts. Patients with duodenal ulcer had a shift of their recorded pH val ues to a more acidic range, Particularly during the night (p < 0.01). Multiple regression analysis showed that an increased percentage of ti me pH was less than 1.2 during the night indicates gastric acid hypers ecretion. In contrast, patients with gastric ulcer or antral gastritis had an increased frequency of alkaline Peaks and Percentage of time s pent at a pH greater than 3 (p < 0.01). The presence of excessive duod enogastric reflux was identified in 39% of these patients as compared with 7% with no gastric mucosal injury (p < 0.01). Delayed gastric emp tying was suggested by prolonged postprandial alkalinization of the ga stric pH record in 25% of the patients. Radionuclide gastric emptying studies confirmed this in 85% of these patients. Conclusions. Gastric pH monitoring allows evaluation of gastric secretory state fluctuation in gastric pH environment, duodenogastric reflux, and gastric emptyin g under physiologic conditions gastroduodenal function.