Dx-pH Measurement System: A Sensitive Device for Detecting Liquid and Aerosolized Supraesophageal Gastric Reflux

Richter J, Evans R. Gastroenterology. 2006;130:4(suppl 2).

Dr. Gregory Weiner of Chula Vista, Calif. And his associates from Restech Corporation in Poway, Calif, and the San Diego State University observed that despite recognition of multiple manifestations of supraesophageal gastric reflux (SEGR), characterization, identification, and response to therapy have evaded understanding due to lack of a suitable detection device. To address this need, Restech developed the Dx minimally invasive catheter with ionic flow sensor to measure pH in liquid or aerosolized droplets at the site of the posterior oropharynx. The authors tested the device’s sensitivity using a standard, 24-hour triple sensor pH catheter (24pH) for verification. Patients in a gastroenterologic practice with chronic symptoms likely due to SEGR and off reflux medication for 4-7 days underwent 24pH with two esophageal and one pharyngeal sensor (Sandhill PH110-V) positioned with a lower esophageal sphincter (LES) indicator at 5 cm above the LES, an indicator 5 cm below the upper esophageal sphincter (UES), and one 1 cm above the UES. The 1.5 mm nasopharyngeal catheter was placed at the oropharynx behind the uvula, above the patients’ discomfort position. Tracings from all four synchronized pH inputs and patient diary were analyzed graphically on a single screen. SEGR was defined as rapid pH drops at the Dx sensor, greater than 3 standard deviations from a 60 second baseline, sequential to drops in pH to less than 4 as measured by 24h pH sensors, then classified as acid pH or weakly acid pH.

A total of 15 patients, at an average age of 57.5 years, with symptoms ranging from cough to tooth enamel loss, sleep apnea, and asthma, were tested. Four had normal 24pH. In 10 patients, 48 Dx-detected SEGR events occurred, with gradual return to baseline and synchronous to esophageal pH drops. All 5 Dx-negative patients had normal 24pH in the esophagus. The authors concluded that SEGR exists in the oropharynx and is detectable with the Dx device; there is a gradient of increasing pH from the esophagus to the oropharynx, the latter rarely less than 4; redefinition of significant pH events above the UES as percentage or more than 3 times the standard deviation in pH drops merits consideration; and clinical management may be influenced by Dx results.


Topics: pH monitoring, GI, 2006

Clinical Library

Quick access to relevant clinical news.

Here is our collection of clinical abstracts, clinician and researcher presentations and other relevant clinical news related to Restech's pH system. You will also find various research and insights covering the reflux spectrum from diagnostics to medical and surgical interventions. Stay tuned for updates!