title: Comparison of reflux frequency during prolonged multichannel intraluminal impedance and pH monitoring on and off acid suppression therapy.
abstract: BACKGROUND
  The aim of this study was to assess and compare reflux frequency during prolonged multichannel intraluminal impedance and pH monitoring with special attention to the 2-hour postprandial interval after the major meal in patients on or off proton pump inhibitor (PPI) therapy.
  
  
  METHODS
  We retrospectively analyzed multichannel intraluminal impedance and pH studies performed in 110 patients monitored on (n=70) or off PPI (n=40) to assess number of acid and nonacid reflux episodes per hour (RE/h).
  
  
  RESULTS
  Patients on PPI had significantly higher mean number of nonacid than acid RE/h during the total monitoring and 2-hour postprandially (pp). The mean number of nonacid RE/h was significantly higher during 2-hour pp than the total monitoring period (4.5 vs. 1.7). Patients off PPI had significantly higher mean number of acid than nonacid RE/h only during the total monitoring. The total number of RE/h was significantly higher during 2-hour pp than the total monitoring (5.1 vs. 2.3). Patients on PPI had significantly higher mean number of nonacid RE/h whereas patients off PPI had significantly higher mean number of acid RE/h throughout total monitoring and 2-hour pp. Number of RE/h was numerically (2.3 vs. 1.7) but not statistically greater off PPI than on PPI during total monitoring.
  
  
  CONCLUSIONS
  The total number of reflux episodes increases during the postprandial period irrespective of PPI therapy. Maximal rate of reflux episodes occurs during the postprandial period and is the same whether taking PPI or not.
authors.affiliation: Division of Gastroenterology, Medical University of South Carolina, Charleston, SC 29425, USA. blonskiw@musc.edu
authors.forename: Wojciech
authors.initials: W
authors.lastname: Blonski
authors.forename: Marcelo F
authors.initials: MF
authors.lastname: Vela
authors.forename: Donald O
authors.initials: DO
authors.lastname: Castell
mesh_terms: D017097:Electric Impedance; D050782:Esophageal pH Monitoring; D004947:Esophagus / Q000378:metabolism* / Q000503:physiopathology; D005260:Female; D005744:Gastric Acid / Q000378:metabolism*; D005764:Gastroesophageal Reflux / Q000175:diagnosis* / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008365:Manometry; D008875:Middle Aged; D019518:Postprandial Period; D011237:Predictive Value of Tests; D054328:Proton Pump Inhibitors / Q000627:therapeutic use*; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D054328:Proton Pump Inhibitors