Impedance pH Guided Approach to Proton Pump Inhibitor-refractory Non-erosive Reflux Disease

Article: Diagnostic utility of impedance-pH monitoring in refractory non-erosive reflux disease CC This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons. org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Patients with persistent symptoms despite proton pump in-hibitor (PPI) make a therapeutic challenge for the clinical gastro-enterologist. There are multiple mechanisms causing PPI failure; proper PPI dosing, patients compliance, functional heartburn (FH) and esophageal hypersensitivity, weakly acidic or alkaline reflux, residual acid reflux, bile acid reflux, nocturnal acid breakthrough and so on. 1 Most patients with gastroesophageal reflux disease who do not respond to a PPI have either non-erosive re-flux disease (NERD) or FH. 2 Combined multichannel intraluminal impedance (MII)-pH helps clarify the association of symptoms with reflux events in patients who do not respond to PPIs. It can determine if there is ongoing pathological acid or non-acid reflux despite the PPI. 3,4 Combined MII-pH has demonstrated that about one-half of patients with persistent symptoms on therapy do not have a temporal correlation between their symptoms and any type of reflux. In addition, about 40% of patients with persistent symptoms on PPI therapy have a temporal association between their symptoms and reflux, primarily of the non-acid type. 2 Using impedance pH metry, Savarino et al 5 classified NERD patients into 3 groups; pH positive NERD, hyper-sensitive esophagus and functional heartburn. 5 Those with symptomatic non-acid reflux were classified as having a hypersensitive esophagus. This means that patients who earlier classified as FH with conventional pH testing were now reclassified as hyper-sensitive esophagus. In one study, the number of patients in the FH subgroup decreased from 43% to 26%. 5 The results of impedance pH testing can thus guide to the next therapeutic step in management of reflux. For patients with symptomatic non-acid reflux, either pathological NERD or hypersensitive esophagus, the therapeutic target is to decrease reflux episodes or esophageal hypersensitivity. Baclofen which reduces the transient lower esophageal sphincter relaxation, or a pain such as antidepressant can be tried. Anti-re