Augmented histamine test--diagnostic and prognostic values.

The results of the augmented histamine test in 107 controls, 48 patients with gastric ulcer and 141 patients with duodenal ulcer are presented. The mean basal acid secretion and maximal acid output (MAO) were significantly higher in duodenal ulcer patients than in normal subjects. Ulcers of the body of the stomach were associated with lower than normal levels of secretion, whereas ulcers of the prepyloric region were associated with higher than normal levels. In this study of 141 patients with duodenal ulcer, 101 patients or 72% had an MAO above the upper limit of normal (20.4 mEq./hr.). Conversely, a patient with an MAO of less than 12.4 mEq./hr. is unlikely to have duodenal ulcer disease. The use of the ratio of MAO to actual body weight did not increase the diagnostic discrimination between normal subjects and those with duodenal ulcer. Duodenal ulcer patients with complications had a significantly higher MAO to histamine than those without complication. The finding of an MAO greater than 40 mEq./hr. is highly suggestive of the presence or the imminence of a complication.