Patterns of 24 h intragastric acidity in duodenal ulcers in children: the importance of monitoring and inhibiting nocturnal acidity.

The objective of this study was to compare the gastric acidity patterns of patients with duodenal ulcers and normal children. Eight patients with duodenal ulcer had their intragastric pH monitored for two consecutive 24 h periods using intragastric glass electrodes. The first 24 h period elucidated pH patterns in the absence of treatment and the second period evaluated the acid suppressive effect of 15 mg/kg of cimetidine when given in three divided doses. Results showed that the ulcer patients were hyperacidic, particularly at midnight. This finding was in marked contrast to the results obtained in the study of normal controls. The mean pH of normal children was above 3 around midnight. This phenomenon is known as intragastric pH inversion. The mean pH 3 time (the cumulative duration of the time for which gastric pH is maintained at > or = pH 3) was significantly shorter in patients with ulcers. However, pH 3 time of these patients significantly increased throughout the 24 h recording period during the daytime and at night after the introduction of cimetidine. This resulted in an induction of apparent nocturnal intragastric pH inversion for the ulcer patients. This study demonstrates the usefulness of 24 h continuous intragastric pH monitoring in children. The data showed that there was a pattern of gastric hyperacidity in pediatric ulcer patients which is clearly distinct from that of normal children, particularly in the patterns occurring at midnight. Cimetidine at 15 mg/kg per day in three divided doses was effective in suppressing secretion even at night.