Abstract
INTRODUCTION: The value of esophageal baseline impedance (BI) in assessing proximal reflux and laryngopharyngeal symptoms (LPSs) is unclear.
METHODS: Two hundred eighteen patients with LPS underwent 24-hour combined hypopharyngeal-esophageal impedance-pH monitoring. Proximal/distal BI was obtained, and a slope-and-intercept model of proximal BI contour was constructed.
RESULTS: Proximal BI correlated with proximal/pharyngeal reflux (r = -0.21, P < 0.01) and reflux symptom index (r = -0.14, P = 0.08). The proximal BI contour model incorporating both the BI change (slope) and BI just below upper esophageal sphincter (intercept) outperformed models using individual BI measures in predicting proximal (Akaike information criterion: 110 vs 251-253) or pharyngeal (akaike information criterion: 32 vs 141-148) reflux.
DISCUSSION: Proximal esophageal impedance contour predicts proximal reflux in patients with LPS.