Study of an Oropharyngeal Aerosolized pH Probe for Diagnosing Laryngopharyngeal Reflux (LPR)

It is estimated that up to 50% of patients with voice disorders and 4-10% of patients seen
in otolaryngology practice experience laryngopharyngeal reflux (LPR). LPR has been
implicated in the pathogenesis of numerous laryngeal disorders, including subglottic
stenosis, laryngeal carcinoma, laryngeal contact ulcers, laryngospasm, and vocal cord
nodules. In the pediatric population, it has been associated with asthma, sinusitis, and
otitis media. Common symptoms include chronic and intermittent hoarseness, vocal fatigue,
globus pharyngeus, cough, postnasal drip, chronic throat clearing, and dysphagia.

Like gastroesophageal reflux disease (GERD), the etiology of LPR is linked to esophageal
sphincter dysfunction. In GERD, the lower esophageal sphincter (LES) is involved, whereas in
LPR, the pathology results from upper esophageal sphincter (UES) dysfunction. However,
diagnosis of LPR is more challenging than that of GERD. The classic reflux-like symptoms of
heartburn and regurgitation are often absent in LPR.

The most widely used diagnostic modality for LPR is symptomatic response to treatment,
including twice daily proton pump inhibitor (PPI) or H2 blocker therapy for several months.
However, the use of a therapeutic modality to make a diagnosis clearly carries
disadvantages, including potentially unnecessary exposure to a drug's side effect profile
and lengthy time to diagnosis. Another diagnostic instrument is the reflux symptom index
(RSI), a validated nine-item questionnaire assessing LPR symptoms. However, LPR symptoms are
fairly nonspecific, also appearing in autoimmune and behavior disorders. Lastly, a 24-hour
triple-pH probe may be the best objective test diagnosing LPR. However, this method is
poorly tolerated by patients and difficulty with ease of administration limits its routine
use. To date, we have remained in search of a minimally invasive and specific test for LPR.

In this study, we will investigate the use of a newly developed oropharyngeal pH probe for
detecting aerosolized acid as an accurate and minimally invasive diagnostic instrument for
LPR. This device has previously been shown to correlate to lower esophageal, upper
esophageal, and lower pharyngeal pH as measured by a 24-hour triple channel bifurcated pH
probe [ACG Poster session by Dr. G Wiener]. The number of oropharyngeal aerosolized acid
reflux events and acid exposure times will be compared to RSI before and after twice daily
proton pump inhibitor therapy. In addition, the correlation between acid reflux events and
acid exposure times as measured by the Dx probe will be more rigorously compared to that
measured by a triple pH probe.

INCLUSION CRITERIA:

Group 1 (negative control):

- RSI ≤ 13

- No history of voice or swallowing disorders

- No active voice or swallowing disorders

- No history of heartburn, regular indigestion, and no prior or current diagnosis of
GERD

Groups 2 and 3 (experimental group):

- Clinical symptoms consistent with LPR as measured by an RSI > 13.

- No other voice or swallowing pathology on clinical exam

EXCLUSION CRITERIA:

- Regular treatment with an H2 blocker or proton pump inhibitor (PPI)

- History of laryngeal/pharyngeal surgery

- Any planned treatment of the larynx/pharynx other than treatment for LPR

- Smoking