Loss of Alkalization in Proximal Esophagus: a New Diagnostic Paradigm for Patients with Laryngopharyngeal Reflux

Cervical esophageal pH monitoring using a pH threshold of < 4 in the diagnosis of laryngopharyngeal reflux (LPR) is disappointing. We hypothesized that failure to maintain adequate alkalization instead of acidification of the cervical esophagus may be a better indicator of cervical esophageal exposure to gastric juice. The aim of this study was to define normal values for the percent time the cervical esophagus is exposed to a pH a parts per thousand yen7 and to use the inability to maintain this as an indicator for diagnosis of LPR. Fifty-nine asymptomatic volunteers had a complete foregut evaluation including pH monitoring of the cervical esophagus. Cervical esophageal exposure to a pH < 4 was calculated, and the records were reanalyzed using the threshold pH a parts per thousand yen7. The sensitivity of these two pH thresholds was compared in a group of 51 patients with LPR symptoms that were completely relieved after an antireflux operation. Compared to normal subjects, patients with LPR were less able to maintain an alkaline pH in the cervical esophagus, as expressed by a lower median percent time pH a parts per thousand yenaEuro parts per thousand 7 (10.4 vs. 38.2, p < 0.0001). In normal subjects, the fifth percentile value for percent time pH a parts per thousand yenaEuro parts per thousand 7 in the cervical esophagus was 19.6%. In 84% of the LPR patients (43/51), the percent time pH a parts per thousand yenaEuro parts per thousand 7 were below the threshold of 19.6%. In contrast, 69% (35/51) had an abnormal test when the pH records were analyzed using the percent time pH < 4. Of the 16 patients with a false negative test using pH < 4, 11 (69%) were identified as having an abnormal study when the threshold of pH a parts per thousand yenaEuro parts per thousand 7 was used. Normal subjects should have a pH a parts per thousand yen7 in cervical esophagus for at least 19.6% of the monitored period. Failure to maintain this alkaline environment is a more sensitive indicator in the diagnosis of the LPR and identifies two thirds of the patients with a false negative test using pH < 4.