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

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00321503
Recruitment Status : Completed
First Posted : May 3, 2006
Last Update Posted : December 9, 2013
Respiratory Technology Corporation
Information provided by (Responsible Party):
Adam Klein, Emory University

Brief Summary:
This study is a test of how well a new FDA-approved device is for diagnosing a condition known as laryngopharyngeal reflux (LPR). The device, which measures pH of the air in the upper throat, will be compared to several other methods for diagnosing laryngopharyngeal reflux.

Condition or disease
Laryngopharyngeal Reflux

Detailed Description:

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.

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Study Type : Observational
Actual Enrollment : 45 participants
Time Perspective: Prospective
Official Title: Diagnosis and Response to Treatment of Laryngopharyngeal Reflux Using an Oropharyngeal Aerosolized pH Probe
Study Start Date : May 2006
Actual Primary Completion Date : May 2007
Actual Study Completion Date : May 2007

Resource links provided by the National Library of Medicine

MedlinePlus related topics: GERD

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population

Pos controls: Subjects visiting the Emory Clinic/Emory Voice center with LPR symptoms.

Neg controls: Random subjects in Atlanta without LPR symptoms. See other descriptions for more details.



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


  • 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

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00321503

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United States, Georgia
Emory Voice Center
Atlanta, Georgia, United States, 30309
Sponsors and Collaborators
Emory University
Respiratory Technology Corporation
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Principal Investigator: Adam Klein, MD Dept of Otolaryngology
Study Chair: Michael M Johns, MD Dept of Otolaryngology / Director of Emory Voice Center
Principal Investigator: Leena Khaitan, MD, MPH Dept of Surgery
Study Director: Justin S Golub, BA Emory University
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Responsible Party: Adam Klein, Principal Investigator, Emory University Identifier: NCT00321503    
Other Study ID Numbers: 1345-2005
DX-1 for LPR ( Other Identifier: other )
First Posted: May 3, 2006    Key Record Dates
Last Update Posted: December 9, 2013
Last Verified: December 2013
Keywords provided by Adam Klein, Emory University:
acid reflux
gastroesophageal reflux
pH probe
proton pump inhibitor
Additional relevant MeSH terms:
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Gastroesophageal Reflux
Laryngopharyngeal Reflux
Esophageal Motility Disorders
Deglutition Disorders
Esophageal Diseases
Gastrointestinal Diseases
Digestive System Diseases
Laryngeal Diseases
Respiratory Tract Diseases