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.