title: Design and implementation of an ambulatory pH monitoring protocol in patients with suspected laryngopharyngeal reflux.
abstract: OBJECTIVE
  Adding a hypopharyngeal sensor to esophageal pH monitoring has been advocated for laryngopharyngeal reflux (LPR). However, selecting the proper pH catheter is problematic because esophageal lengths are variable among individuals.
  
  
  OBJECTIVE
  To design and implement a new pH monitoring protocol for LPR.
  
  
  METHODS
  Design parameters were defined prospectively: single-probe, triple-sensor pH catheter with sensors located in the hypopharynx (1-3 cm above upper esophageal sphincter) and in proximal and distal esophagus (20 cm and 5 cm above lower esophageal sphincter, respectively). Esophageal lengths were determined in a study population undergoing esophageal manometry. Optimal pH sensor spacings were determined using the least number of catheters to satisfy the design parameters. The protocol was implemented in consecutive subjects with suspected LPR.
  
  
  RESULTS
  Distribution of esophageal lengths was determined in 1,043 subjects. In 92% of the study population, three pH catheters (3-15, 6-15, and 9-15 sensor-spacings) would satisfy the design criteria. Forty-one subjects with suspected LPR underwent the pH protocol. An abnormal pH test was found in 40 subjects (98%) with triple-sensor combination compared with 29 subjects (71%) if only dual esophageal sensors were used.
  
  
  CONCLUSIONS
  Single-probe pH monitoring of the hypopharynx and esophagus was feasible. Adding a hypopharyngeal pH sensor increased the detection of abnormal acid reflux more often than traditional dual-sensor esophageal pH monitoring.
authors.affiliation: Division of Gastroenterology/Hepatology, University of Louisville School of Medicine, Louisville, KY 40202, USA.
authors.forename: Steve
authors.initials: S
authors.lastname: Harrell
authors.forename: Ben
authors.initials: B
authors.lastname: Evans
authors.forename: Steve
authors.initials: S
authors.lastname: Goudy
authors.forename: Welby
authors.initials: W
authors.lastname: Winstead
authors.forename: Eric
authors.initials: E
authors.lastname: Lentsch
authors.forename: Jennifer
authors.initials: J
authors.lastname: Koopman
authors.forename: John M
authors.initials: JM
authors.lastname: Wo
mesh_terms: D002404:Catheterization; D004867:Equipment Design; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis* / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007818:Laryngeal Diseases / Q000175:diagnosis* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000295:instrumentation* / Q000379:methods