BackgroundMean nocturnal baseline impedance (MNBI) and post-reflux swallow-induced peristaltic wave (PSPW) index are able to increase the diagnostic yield of impedance-pH and are associated to proton pump inhibitor (PPI) response. Few data concerning these variables in patients with extra-esophageal symptoms (EES) are available. AimsTo evaluate, in EES patients, the role of the conventional and new impedance-pH variables in diagnosing GERD and the predictive value of impedance-pH variables for PPI response. MethodsConsecutive patients presenting suspected GERD-related EES underwent impedance-pH. Patients treated in the last six months with double dose PPI therapy were enrolled. The presence of concomitant typical symptoms was assessed. Results239 EES patients were studied; 102 responders and 137 non-responders. Eighty-one (34%) were affected by non-erosive reflux disease (NERD), 61 (26%) presented reflux hypersensitivity (RH) and 97 (40%) were non-GERD. In NERD and RH groups, a significantly higher proportion of patients with pathological PSPW index or MNBI values compared to non-GERD group was observed. 24 (25%) non-GERD patients presented a pathological PSPW index and/or MNBI. Pathological PSPW index, MNBI and presence of typical symptoms were associated to PPI response. ConclusionsMNBI and PSPW index measurement increases the diagnostic yield of impedance-pH; abnormal values are associated with a satisfactory response to acid-suppressive therapy in EES patients.
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