title: Improved diagnosis of gastro-oesophageal reflux in patients with unexplained chronic cough.
abstract: BACKGROUND
  Symptoms, oesophageal pHmetry and proton pump inhibitor treatment are used for diagnosing gastro-oesophageal reflux-related cough. Weakly acidic reflux is now increasingly associated with reflux symptoms such as regurgitation or chest pain.
  
  
  OBJECTIVE
  To study the association between weakly acidic reflux and cough in a selected, large group of patients with unexplained chronic cough.
  
  
  METHODS
  A total of 100 patients with chronic cough (77 'off' and 23 'on' a proton pump inhibitor) were studied using impedance-pHmetry for reflux detection and manometry for objective cough monitoring. Symptom Association Probability (SAP) Analysis characterized the reflux-cough association.
  
  
  RESULTS
  Acid reflux could be a potential mechanism for cough in 45 patients (with either heartburn, high acid exposure or +SAP for acid reflux). Weakly acidic reflux could be a potential mechanism for cough in 24 patients (with either increased oesophageal volume exposure, increased number of weakly acidic reflux or +SAP for weakly acidic reflux). Reflux could not be identified as a potential mechanism for cough in 31 patients.
  
  
  CONCLUSIONS
  A positive association between cough and weakly acidic reflux was found in a significant subgroup of patients with unexplained chronic cough. Impedance-pH-manometry identified patients in whom cough can be related to reflux that would have been disregarded using the standard diagnostic criteria for acid reflux.
authors.affiliation: Center for Gastroenterological Research, K.U. Leuven, Belgium.
authors.forename: K
authors.initials: K
authors.lastname: Blondeau
authors.forename: L J
authors.initials: LJ
authors.lastname: Dupont
authors.forename: V
authors.initials: V
authors.lastname: Mertens
authors.forename: J
authors.initials: J
authors.lastname: Tack
authors.forename: D
authors.initials: D
authors.lastname: Sifrim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D003371:Cough / Q000150:complications*; D017097:Electric Impedance; D005260:Female; D005745:Gastric Acidity Determination; D005764:Gastroesophageal Reflux / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008365:Manometry; D008875:Middle Aged