- A metallic, alkaline, divalent earth element; atomic no. 56, atomic wt. 137.327. Insoluble salts are often used in radiology as contrast media. [G. barys, heavy]- b. hydroxide a caustic compound combined with calcium hydroxide in a carbon dioxide absorbent; used in anesthetic circuits. SEE ALSO: absorbent (3).- b. meal oral administration of b. sulfate suspension for radiographic study of the upper gastrointestinal tract (British usage).- b. oxide, b. monoxide it is caustic, forming the strong base, Ba(OH)2, in water; used as a dehydrating agent. SYN: baryta.- b. sulfate given as a suspension orally, rectally, or through a tube, for radiographic demonstration of a part of the gastrointestinal tract. See enteroclysis, b. enema.- b. swallow oral administration of b. sulfate suspension for radiographic investigation of the hypopharynx and esophagus.
* * *bar·i·um 'bar-ē-əm, 'ber- n1) a silver-white malleable toxic bivalent metallic element of the alkaline-earth group that occurs only in combination symbol Ba see ELEMENT (table)2) barium sulfate
* * *bar·ium (Ba) (barґe-əm) [L., from Gr. baros weight] a pale, yellowish, metallic element belonging to the alkaline earths; atomic number 56, atomic weight 137.34. Its acid-soluble salts are poisonous; see barium poisoning, under poisoning.
Medical dictionary. 2011.