Objectives: To analyze laryngopharyngeal reflux (LPR) as an acidic, nonacidic, or mixed type according to 24-hour multi-channel intraluminal impedance (MII) pH monitoring and the clinical characteristics of each type.
Methods: Ninety patients were prospectively enrolled in this study. All patients underwent 24-hour MII pH monitoring as a diagnostic tool. Eighty-three patients were diagnosed with LPR. The patients were classified into three groups according to the pH of the hypopharyngeal probe: the acid reflux group, nonacid reflux group, and mixed reflux group. Subjective symptoms and objective findings were evaluated based on patients' responses to the Short Form 12 Survey (SF-12), LPR health-related quality of life (LPR-HRQOL), reflux symptom index, and reflux finding score.
Results: The results of each group were compared. As a result, 34 patients were classified into the nonacid reflux group and 49 into the mixed reflux group. There were no patients classified as having acid reflux alone. There was no significant difference between the two groups when comparing the reflux symptom index, reflux finding score, LPR-HRQOL, or the mental component score of the SF-12. However, the physical component score of the SF-12 was higher in the nonacid reflux group (P=0.018). The DeMeester composite score (P=0.015) and total number of LPR events (P=0.001) were lower in the nonacid reflux group than in the mixed reflux group.
Conclusion: In conclusion, no LPR patient had only acid reflux. The nonacid reflux LPR patients showed similar clinical characteristics and findings compared to the mixed reflux group, but exhibited significantly fewer LPR episodes.
Keywords: 24-Hour Multichannel Intraluminal Impedance pH Monitoring; Laryngopharyngeal Reflux; Reflux Type.