S946 Evaluating Acid Exposure Time Thresholds in the Diagnosis of Laryngopharyngeal Reflux

Introduction: Laryngopharyngeal reflux (LPR) is a challenging clinical entity to diagnose due to the absence of standardized diagnostic criteria. While acid exposure time (AET) is a validated metric in gastroesophageal reflux disease (GERD), its role in diagnosing LPR remains unclear. Given the heightened sensitivity of laryngeal tissue to acid compared with esophageal tissue, we hypothesize that LPR may be identified with a lower AET compared with GERD. Our study aims to assess an AET threshold that captures majority of LPR cases. Methods: We performed a retrospective analysis of adult patients who were diagnosed in otolaryngology clinic with LPR and had pH testing between the dates of March 2005 and November 2023. Exclusion criteria included head and neck cancer, history of radiation, and eosinophilic esophagitis. Patient charts were reviewed for relevant data, including demographics, symptoms, pH testing results, endoscopic findings, and histology. Analysis includes descriptive statistics. Results: There were 47 patients who met criteria for the study. Bravo testing was performed in 85% of patients, while pH impedance catheter testing was used in 15% of patients. Twenty-nine point seven percent of tested patients had an abnormal AET (>6%) per GERD criteria. On acid suppression therapy, 44.7% of patients experienced symptomatic and 29.8% laryngoscopic improvement. Mean AET testing was ≥5.4%. Conclusion: Mean AET threshold was elevated in LPR patients, suggesting that pH testing may be a useful marker. Further studies are needed to assess an exact AET threshold for diagnosis of LPR.