title: Endoscopic pH monitoring for patients with suspected or refractory gastroesophageal reflux disease.
abstract: BACKGROUND
  Wireless pH studies can offer prolonged pH monitoring, which may potentially facilitate the diagnosis and management of patients with gastroesophageal reflux disease (GERD). The aim of the present study was to evaluate the detection rate of abnormal esophageal acid exposure using prolonged pH monitoring in patients with suspected or refractory GERD symptoms.
  
  
  METHODS
  Patients undergoing prolonged ambulatory pH studies for the evaluation of GERD-related symptoms were assessed. Patients with a known diagnosis of GERD were tested on medical therapy, while patients with suspected GERD were tested off therapy. The wireless pH capsules were placed during upper endoscopy 6 cm above the squamocolumnar junction.
  
  
  RESULTS
  One hundred ninety-one patients underwent a total of 198 pH studies. Fifty ambulatory pH studies (25%) were excluded from the analysis: 27 patients (14%) had insufficient data capture (less than 18 h on at least one day of monitoring), 15 patients had premature capsule release (7%), seven were repeat studies (3.5%) and one had intolerable pain requiring capsule removal (0.5%). There were 115 patients undergoing pH studies who were off medication, and 33 patients were on therapy. For the two groups of patients, results were as follows: 32 (28%) and 22 (67%) patients with normal studies on both days; 58 (50%) and five (15%) patients with abnormal studies on both days; 18 (16%) and three (9%) patients with abnormal studies on day 1 only; and seven (6%) and three (9%) patients with abnormal studies on day 2 only, respectively.
  
  
  CONCLUSIONS
  Prolonged 48 h pH monitoring can detect more abnormal esophageal acid exposure but is associated with a significant rate of incomplete studies.
authors.affiliation: Department of Gastroenterology, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: B G
authors.initials: BG
authors.lastname: Turner
authors.forename: J R
authors.initials: JR
authors.lastname: Saltzman
authors.forename: L
authors.initials: L
authors.lastname: Hua
authors.forename: R
authors.initials: R
authors.lastname: Maurer
authors.forename: Natan
authors.initials: N
authors.lastname: Feldman
authors.forename: D L
authors.initials: DL
authors.lastname: Carr-Locke
authors.forename: R
authors.initials: R
authors.lastname: Burakoff
authors.forename: J J
authors.initials: JJ
authors.lastname: Liu
mesh_terms: D000328:Adult; D053704:Capsule Endoscopy; D050782:Esophageal pH Monitoring / Q000009:adverse effects / Q000592:standards*; D004945:Esophagoscopy / Q000379:methods* / Q000592:standards; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory; D016896:Treatment Outcome