title: The LES locator: accurate placement of an electrode for 24-hour pH measurement with a combined solid state pressure transducer.
abstract: Twenty-four-hour esophageal pH monitoring is the gold standard for diagnosing gastroesophageal reflux disease. A possible limitation to the widespread use of this test is that manometry is required for accurate placement of the pH electrode 5 cm above the lower esophageal sphincter. We compared the accuracy of a single solid state pressure transducer, combined with a pH electrode, in determining the proximal border of the lower esophageal sphincter (LES) with the values obtained from stationary manometry in 40 patients referred to our laboratory for 24-h pH studies. Not only was there a strong correlation (r = 0.9) between LES values obtained by the two techniques, but none of the values obtained by the single solid state transducer were outside the clinically accepted range of greater than +/- 3 cm. The presence of a hiatal hernia or low sphincter pressure did not affect these measurements. The larger probe was tolerated somewhat less well (p = 0.02) than a standard antimony electrode during the prolonged pH studies. In conclusion, a single solid state pressure transducer on a pH probe with the help of a LES locator accurately identifies the proximal border of the LES. Therefore, stationary esophageal manometry is no longer needed prior to 24-h pH monitoring, potentially making this important clinical tool available to a wider variety of clinicians at all levels of the health care system, in investigating gastroesophageal reflux and its protean clinical presentations.
authors.affiliation: Division of Gastroenterology, University of Alabama, Birmingham.
authors.forename: S
authors.initials: S
authors.lastname: Singh
authors.forename: J E
authors.initials: JE
authors.lastname: Price
authors.forename: J E
authors.initials: JE
authors.lastname: Richter
mesh_terms: D000328:Adult; D000368:Aged; D002637:Chest Pain / Q000209:etiology; D004566:Electrodes; D004867:Equipment Design; D004947:Esophagus / Q000502:physiology*; D005260:Female; D005764:Gastroesophageal Reflux / Q000150:complications / Q000175:diagnosis*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008365:Manometry / Q000295:instrumentation; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation; D011237:Predictive Value of Tests; D012044:Regression Analysis; D014159:Transducers