Role of Ambulatory Distal Esophageal pH Monitoring in Patients With Laryngopharyngeal Reflux (LPR) and Gastroesophageal Reflux Disease (GERD)

Abstract

Introduction: LPR is primarily a clinical diagnosis based on symptoms such as cough, globus, hoarseness and throat clearing thought to be due to reflux of gastric contents into larynx. Some of these patients do not have typical symptoms of heartburn and acid regurgitation which can make the diagnosis challenging. Though not 100% sensitive, the gold standard test for detection of reflux is distal esophageal pH monitoring with 24-hour pH or 48-hour pH testing. Therefore, our aim was to assess the role of distal esophageal pH testing in patients with LPR. Methods: The study group (Group A) consisted of the patients with a diagnosis of LPR who underwent either 24 pH test with a single probe transnasal catheter positioned 5 cm above gastroesophageal junction (GEJ) or 48 hour wireless bravo probe placed endoscopically 6 cm above the GEJ in our GI lab from 2006 to 2014. Group B consisted patients with the diagnosis of GERD only (heartburn or acid regurgitation more than two days a week) and group C comprised of patients with a diagnosis of GERD and LPR. In addition to pH testing, all groups had high resolution esophageal manometry (HREM) and otolaryngeal (ENT) evaluation. Variables such as age, gender, BMI and pH parameters including total acid exposure, supine and upright acid exposure, Symptom index (SI), Symptom sensitivity index (SSI) and symptom association probability (SAP) were noted. Results: A total of 239 patients underwent pH testing during the study period. There were 67 patients in Group A (LPR only), 107 patients in Group B (GERD only) and 68 patients in group C (GERD+ LPR). Only 43.3% in Group A, 50.5% in group B and 55.4% in group C had abnormal pH testing (Table 1). There were no significant differences in the three groups in terms of total, supine and upright acid exposure. SI, SSI and SAP were lower in group A than in group B and group C (although not statistically significant).Table 1: Esophageal pH Testing in LPR and GERDConclusion: Esophageal pH testing is normal in approximately half the patients with a clinical diagnosis of LPR, GERD or a combination. Hence, a diagnosis of LPR cannot be reliably made on the results of distal esophageal pH monitoring alone.