Impedance baseline and reflux perception in responder and non-responder non-erosive reflux disease patients.

BACKGROUND: It was recently shown that GERD patients have lower impedance baseline (IB) values than healthy controls and, that the esophageal acid exposure time (AET) correlates with IB levels. GOALS: To explore the sensitivity of IB measurements in NERD patients, responders and non-responders to PPIs, when compared with pH-impedance (MII-pH) variables, and to evaluate whether this variable could represent a marker of GERD symptoms. Reproducibility and inter-observer agreement of IB measurement were also assessed. Study. MII-pH tracings from 44 NERD responders and 22 non-responders were analysed. Ten healthy volunteers underwent the same protocol. IB values were measured at the distal and proximal esophagus. IB was also analysed in a subgroup of patients and in controls with two methods and by two blinded operators. RESULTS: Mean IB values at the distal esophagus were significantly lower in NERD patients than in controls. IB values did not differ between responders and non-responders. Of the 8 responders with negative AET and symptom association probability (SAP), 3 (37.5%) showed IB values lower than controls. IB values in responders with positive and negative SAP were similar (1832 (1596-2068) Ω vs 1667 (1361-1973) Ω, p: n.s.). No differences were found between the IB values measured with the two methods and the inter-observer agreement was good. CONCLUSIONS: IB is a promising and easy to calculate MII-pH variable and appears to increase the sensitivity of MII-pH monitoring. IB values cannot predict PPI response and are not associated with reflux perception in NERD patients.

Increased frequency and enhanced perception of reflux in non-erosive reflux disease patients non-responders to proton pump inhibitors.

BACKGROUND: The unsatisfactory response to medical treatment in non-erosive patients is becoming a real challenge for gastroenterologists. Non-responder patients, evaluated under treatment, present symptoms which are related to non-acidic, mixed and proximal reflux episodes. METHODS: To elucidate the reflux pattern and mechanisms related to persistence of symptoms despite treatment, oesophageal pH-impedance was performed in 55 non-erosive responder and 24 non-responder patients, studied off therapy. Ten responder and 10 non-responder patients underwent a repeated study during proton pump inhibitor treatment. RESULTS: Non-responders were characterised by a higher overall number and larger proportion of symptomatic reflux episodes. Non-responders were also characterised by an enhanced sensitivity to acidic, mixed and proximal refluxes. Weakly acidic reflux accounted for 29% of symptomatic refluxes in non-responders and 34% in responders. Proportions of acidic and weakly acidic reflux episodes were comparable both in responders and non-responders when analysed off and on treatment. CONCLUSIONS: An increased overall number of reflux episodes and enhanced sensitivity to reflux are strongly associated with treatment failure. Treatment strategies aimed at decreasing transient lower oesophageal sphincter relaxations, pain modulators or anti-reflux surgery should be considered in non-responders in whom a significant relationship between symptoms and reflux has been confirmed.