title: Diagnostic Utility of Impedance-pH Monitoring in Refractory Non-erosive Reflux Disease.
abstract: OBJECTIVE
  Approximately one-third of non-erosive reflux disease (NERD) patients are refractory to proton pump inhibitors (PPI) and face a therapeutic challenge. Therefore, it is important to differentiate between pathological and non-pathological reflux utilizing multichannel intraluminal impedance-pH (MII-pH) to analyze symptom-reflux association and diagnose true NERD versus hyper-sensitive esophagus (HE) and functional heartburn (FH). Herein, we evaluated the diagnostic yield of MII-pH in refractory NERD and sub-classified it based on quantity and quality of acid/non-acid reflux and reflux-symptom association.
  
  
  METHODS
  Sixty symptomatic NERD patients on twice daily PPI for > 2 months were prospectively evaluated by MII-pH. Distal and prox-imal refluxes, bolus exposure time (BET), esophageal acid exposure time, symptom index (SI) and symptom association proba-bility (SAP) were measured.
  
  
  RESULTS
  Thirty-two (53%) patients had BET > 1.4% (MII-pH positive-true NERD), while 28 (47%) had BET < 1.4% (MII-pH negative NERD) where SI and SAP were negative in 15/60 (25%; categorized as FH) and SI or SAP were positive in 13/60 (22%; identi-fied as HE). Thirty-eight (63%) patients reported significant SI or SAP parameters where > 80% of symptoms were associated with non-acid reflux. The number of distal refluxes in true NERD versus FH or HE were significantly different, but not between FH and HE.
  
  
  CONCLUSIONS
  Approximately 60% of refractory PPI NERD patients had positive reflux-symptom association, primarily due to non-acid reflux. Nearly half of NERD patients on PPI had normal MII-pH monitoring, sub-divided further into FH and HE equally.(J Neurogastroenterol Motil 2014;20:497-505).
authors.affiliation: Section of Gastroenterology, Department of Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.
authors.forename: Mohammed Q
authors.initials: MQ
authors.lastname: Khan
authors.affiliation: Section of Gastroenterology, Department of Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.
authors.forename: Ali
authors.initials: A
authors.lastname: Alaraj
authors.affiliation: Section of Gastroenterology, Department of Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.
authors.forename: Fahad
authors.initials: F
authors.lastname: Alsohaibani
authors.affiliation: Section of Gastroenterology, Department of Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.
authors.forename: Khalid
authors.initials: K
authors.lastname: Al-Kahtani
authors.affiliation: Section of Gastroenterology, Department of Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.
authors.forename: Sahar
authors.initials: S
authors.lastname: Jbarah
authors.affiliation: Section of Gastroenterology, Department of Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.
authors.forename: Hamad
authors.initials: H
authors.lastname: Al-Ashgar
keywords: Impedance-pH monitoring; Non-erosive reflux disease; Refractory NERD