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Updated: Jul 7, 2026

Simultaneous Laryngopharyngeal and Conventional Esophageal pH Monitoring
Published on: December 14, 2020
[Determination of normal values of extraesophageal reflux in 24-h two-channel pH testing]
P Jecker1, R Schuon, C Morales
1Klinik für Hals-Nasen-Ohren-Heilkunde, Klinikum Bad Salzungen gGmbH, Lindigallee 3, 36433, Bad Salzungen, Deutschland. peter.jecker@klinikum-badsalzungen.de
Abstract:
Extraesophageal reflux (EER) causes multiple diseases of the upper aerodigestive tract. EER is diagnosed by two-channel pH testing. However, little data exist about normal values. Therefore, we performed ambulatory two-channel pH testing in healthy volunteers and determined normal values for the number of reflux episodes, fraction, and reflux area index. These values were determined for pH =4 as commonly used as well as for pH =5 because pepsin is still generated at a pH of 5. In 40 healthy volunteers, ambulatory 24-h two-channel pH testing was performed. Asymptomatic gastroesophageal reflux was excluded by the DeMeester index. Ten subjects with a DeMeester score >14.72 were excluded from the evaluation. In the other patients, the mean number of reflux episodes was 2.6+/-0.9 (95(th) percentile 4.4), the fraction of pH =4 was 0.1+/-0.04% (95(th) percentile 0.2), and the reflux area index was 3.8+/-1.5 (95(th) percentile 6.8). Data for the threshold of pH =5 were 10 times higher.
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