title: Ambulatory reflux monitoring for diagnosis of gastro-esophageal reflux disease: Update of the Porto consensus and recommendations from an international consensus group.
abstract: BACKGROUND
  An international group of experts evaluated and revised recommendations for ambulatory reflux monitoring for the diagnosis of gastro-esophageal reflux disease (GERD).
  
  
  METHODS
  Literature search was focused on indications and technical recommendations for GERD testing and phenotypes definitions. Statements were proposed and discussed during several structured meetings.
  
  
  RESULTS
  Reflux testing should be performed after cessation of acid suppressive medication in patients with a low likelihood of GERD. In this setting, testing can be either catheter-based or wireless pH-monitoring or pH-impedance monitoring. In patients with a high probability of GERD (esophagitis grade C and D, histology proven Barrett's mucosa >1 cm, peptic stricture, previous positive pH monitoring) and persistent symptoms, pH-impedance monitoring should be performed on treatment. Recommendations are provided for data acquisition and analysis. Esophageal acid exposure is considered as pathological if acid exposure time (AET) is greater than 6% on pH testing. Number of reflux episodes and baseline impedance are exploratory metrics that may complement AET. Positive symptom reflux association is defined as symptom index (SI) >50% or symptom association probability (SAP) >95%. A positive symptom-reflux association in the absence of pathological AET defines hypersensitivity to reflux.
  
  
  CONCLUSIONS
  The consensus group determined that grade C or D esophagitis, peptic stricture, histology proven Barrett's mucosa >1 cm, and esophageal acid exposure greater >6% are sufficient to define pathological GERD. Further testing should be considered when none of these criteria are fulfilled.
authors.affiliation: Digestive Physiology, Hospices Civils de Lyon and Lyon I University, Inserm U1032, LabTAU, Lyon, France.
authors.forename: S
authors.identifier: http://orcid.org/0000-0002-7798-7638
authors.initials: S
authors.lastname: Roman
authors.affiliation: Division of Gastroenterology, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: C P
authors.identifier: http://orcid.org/0000-0002-3388-0660
authors.initials: CP
authors.lastname: Gyawali
authors.affiliation: Division of Gastroenterology, Department of Surgical, Oncological and Gastroenterological Sciences, Padua, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Savarino
authors.affiliation: Division of Gastroenterology, Department of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: R
authors.initials: R
authors.lastname: Yadlapati
authors.affiliation: Department of Gastroenterology, Bordeaux University Hospital, and Université de Bordeaux, Bordeaux, France.
authors.forename: F
authors.initials: F
authors.lastname: Zerbib
authors.affiliation: Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: J
authors.initials: J
authors.lastname: Wu
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Scottsdale, AZ, USA.
authors.forename: M
authors.initials: M
authors.lastname: Vela
authors.affiliation: Division of Gastroenterology, University Clinics for Visceral Surgery and Medicine, Bern University Hospital, Bern, Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Tutuian
authors.affiliation: Department of Surgery, University of Washington, Seattle, WA, USA.
authors.forename: R
authors.initials: R
authors.lastname: Tatum
authors.affiliation: Center for Digestive Diseases, Bart's and the London School and Dentistry, London, UK.
authors.forename: D
authors.initials: D
authors.lastname: Sifrim
authors.affiliation: Department of Internal Medicine, Israelitic Hospital, University of Hamburg, Hamburg, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Keller
authors.affiliation: Department of Gastroenterology, Abdominal Center, St. Claraspital, Basel, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Fox
authors.affiliation: Division of Gastroenterology, Department of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Pandolfino
authors.affiliation: Gastroenterology and Hepatology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: A J
authors.initials: AJ
authors.lastname: Bredenoord
mesh_terms: D050782:Esophageal pH Monitoring / Q000379:methods*; D005764:Gastroesophageal Reflux / Q000175:diagnosis*; D006801:Humans; D018670:Monitoring, Ambulatory / Q000379:methods*
keywords: Gastro-esophageal reflux disease; esophageal acid exposure; esophagitis; reflux monitoring