• Diagnosing laryngeal reflux with voice disorders using pharyngeal pH examination:A systematic review study
  • Fatemeh Toupal,1 Ayda Aghaei,2 Fatemeh Alesaadi,3 Nastaran Jahanshahi,4 Sadaf Hosseini,5 Pouya Ghaderi,6,*
    1. Behbahan Faculty of Medical Sciences
    2. Larestan University of Medical Sciences
    3. Behbahan Faculty of Medical Sciences
    4. Alborz University of Medical Sciences
    5. Shahid Beheshti University of Medical Sciences
    6. Mashhad Islamic Azad University of Medical Sciences


  • Introduction: Laryngeal reflux (LPR) is an inflammatory disease of the upper gastrointestinal tract. It involves the retrograde movement of liquid and gas contents of the stomach through the esophagus to the pharynx and throat. Many laryngeal disorders have been attributed to LPR, including: reflux laryngitis, subglottic stenosis, contact ulcers and granulomas, and even laryngeal carcinoma. Analysis of the pH study characteristics of LPR patients may improve the understanding of the pathophysiological mechanisms of LPR. In clinical practice, objective diagnostic methods are also used, such as pH monitoring, pH-MII monitoring, oropharyngeal pH monitoring or pepsin detection test. Pharyngeal pH monitoring is a standard management of laryngeal reflux (LPR). Scores metrics including: number of reflux episodes, reflux time, and Ryan score. The present study was conducted with the aim of investigating patients with voice disorders caused by LPR by monitoring the pharynx.
  • Methods: Search method: In this article, we collected the required data by using keywords and also by searching in data bases such as Google Scholar, Scopus, ProQuest and PubMed. Our statistical population is all available articles published until 2022. After evaluating the findings as well as the quality of the data, we analyzed a total of 14 articles.
  • Results: The threshold for detecting acid reflux events was considered to be 5.5 and 5 for upright and lying positions, respectively. The results of oral and pharyngeal pH monitoring showed that out of 161 patients, 82 patients had non-acid reflux and 79 patients had acid reflux. Among patients who were diagnosed with acid reflux, 62% had acid reflux in the upright position, 25% had acid reflux in the supine position, and 13% had acid reflux in both the supine and upright positions. The number of patients with vertical LPR was significantly higher compared to supine LPR. In addition, comparing the vertical LPR group with the lying LPR group in terms of pH results, the number of LPR episodes and the total Ryan score in the standing group were significantly higher than the lying group. However, the percentage of time below baseline pH and parameters of the longest reflux period were significantly higher in the supine group. Information on the prevalence of LPR in the population is scarce. A study from Greece estimated 18.8% based on RSI criteria, while a second Greek study reported an LPR prevalence of 8.5%. The efficiency of 24-hour two-probe pH monitoring (acid exposure in the proximal probe greater than 0.02%) for diagnosing LPR is low, and changes in diagnostic criteria should be considered. The frequency of LPR assessed by RSI and RFS in patients with voice disorders is approximately 47%. This suggests that causes other than gastroesophageal reflux, such as allergies, should be investigated in approximately 25% to 50% of patients with voice disorders. Approximately half of patients with voice disorders have LPR, and only a subset of these patients have evidence of GERD.
  • Conclusion: Fiber optic laryngoscopy (RFS) findings in addition to RSI seem to be important in diagnosing the possible cause of reflux in voice disorders and can be an indicator to start anti-reflux treatment. Acid exposure time as measured in the proximal probe of a dual 24-hour pH probe may need to be re-evaluated as one of the diagnostic criteria for LPR.
  • Keywords: larynx, reflux, voice disorders