Gastric tubes, meals, acid, and analysis: rise and decline.

The stomach tube was first used to administer food and medication or to remove poisonous substances. Later, it served to aspirate the stomachs of patients with gastric retention. Chemical analysis of stomach contents after a meal was first suggested in 1871 and quickly became an important laboratory procedure as various test-meal stimuli and more flexible tubes were developed. Quantitative estimations of free and total acidity were made by titration with 0.01 mol/L sodium hydroxide and specific indicators. Pentagastrin has supplanted secretagogues such as histamine and betazole; meal stimulation, tubeless tests, and other tests of gastric secretion are no longer used clinically. Tests of gastric acid secretion have been used in the diagnosis of upper gastrointestinal lesions and to help select the type of surgical procedure for gastric and duodenal ulcers, but the tests have decreased in importance because of their limited diagnostic sensitivity and specificity. Today, fiberoptic endoscopy is replacing gastric analysis as well as radiologic examination.