Convenient Method of Measuring Baseline Impedance for Distinguishing Patients with Functional Heartburn from those with Proton Pump Inhibitor-Resistant Endoscopic Negative Reflux Disease

Abstract

Background: Combined 24-h intraesophageal pH-multichannel intraluminal impedance (24MII-pH) used for assessing gastroesophageal reflux disease by measuring baseline impedance (BI) requires a 24-h measuring period. In the present study, we developed a quick method of measuring BI and evaluated its usefulness in classifying patients with proton pump inhibitor (PPI)-refractory non-erosive reflux diseases (NERD) as having functional heartburn (FH) or endoscopic-negative reflux disease (ENRD). Methods: Ninety-one NERD patients without esophageal motility disorder underwent 24MII-pH monitoring while on a PPI. The measurements of the mean nocturnal BI (MNBI) and short MNBI were assessed at 3 times (at about 1: 00, 2: 00, and 3: 00 am) for 10 min and 30 s respectively. The measurement of the simple mean BI (MBI) was performed once 30 s at about 11: 00 am. Results: Ninety-one patients were divided into 2 groups: 59 with ENRD and 32 with FH. The cutoff, specificity, and sensitivity for distinguishing patients with FH were as follows: MNBI, 2,874.1 Ω, 72%, and 72%; short MNBI, 2,857.6 Ω, 74%, and 84%; and simple MBI, 2,874.1 Ω, 86%, and 78% respectively. Conclusion: Measuring the simple MBI is a quick method and is useful for distinguishing patients with FH from those in a cohort with PPI-refractory NERD.