Breath-analysis tests in gastroenterology.

Progress report Breath-analysis tests in gastroenterologyThough the term 'breath-analysis test' conjures up images of policemen and errant motorists, it has a different connotation when used by gastro- enterologists.Analysis of certain constituents in breath exhaled after the administration of various substrates has been found to have potentially important applications, and interest in breath tests is increasing for a number of valid reasons.First of all, in some cases the gases measured are produced in chemical reactions that are difficult to quantitate in any other way, because they take place either inside cells or in the inaccessible regions of the gastrointestinal tract.Secondly, exhaled breath is easy to collect by simple, non-invasive, and aesthetically acceptable means, often using disposable or cheap apparatus readily adapted to local hospital or even field conditions.Thirdly, serial studies can be performed in order to assess the course of a disease or its response to treatment without causing pain or hardship.Fourthly, the analysis of the breath specimens is simple, automated, and potentially highly cost-effective.Fifthly, breath tests do not depend on good pulmonary function for their accuracy to the same degree that tests involving, for example, urine depend on accurate collections and on good renal function.This is because the gases being sought diffuse readily across biological membranes down concentration gradients, pass into plasma and thence into alveolar air.Admittedly, severe metabolic or respiratory acid-base problems would interfere with a breath test, but in the presence of these abnormalities such tests probably would not be performed.Finally, breath tests are safe for use in adults and some of them are safe for use in children.In this report each of the exhaled gases of gastroenterological interest will be considered and the present methods, applications, and areas of potential usefulness wilibe reviewed.14C Carbon Dioxide (4C02) TOTAL C02 COLLECTION METHOD '4C02 AND MANNITOL Mannitol is a poorly absorbed alcohol, closely related in chemical structure to mannose.It has long been known to be metabolized by bacteria, and has 310Alvin Newman