title: Are 10 wet swallows an appropriate sample of esophageal motility? Yes and no.
abstract: BACKGROUND
  Traditionally 10 wet swallows are used to assess esophageal motility. Given this relative small number of swallows concerns have been raised whether the abnormal findings based on 10 wet swallows would persist with another set of 10 wet swallows.
  
  
  OBJECTIVE
  To evaluate whether 10 wet swallows during esophageal manometry is an adequate sampling of esophageal motility.
  
  
  METHODS
  Over a 4-month-period 100 consecutive patients (excluding patients with achalasia) were given 20 liquid (5 ml each) swallows. The standard manometry technique in our laboratory was performed using 10 wet swallows with pressure transducers placed 4 cm and 9 cm above the lower esophageal sphincter (LES). The diagnosis was based on the initial 10 swallows. The additional 10 swallows were blinded and separately analyzed, then compared with the initial swallows for each patient.
  
  
  RESULTS
  Of the 100 studies (64 women; mean age 51; range 21-85), 91 had a consistent diagnosis for both pairs of 10 swallows. The number of abnormal swallows (ineffective or simultaneous) differed between the 2 sets of 10 swallows in 9 patients, but, when the first 10 were analyzed vs. all 20 swallows only 2 patients had discordant diagnoses. There was an excellent agreement between the 1st and 2nd set of 10 swallows (kappa = 0.846) and between the first 10 and all 20 swallows (kappa = 0.965).
  
  
  CONCLUSIONS
  Ten wet swallows are sufficient for making a manometric diagnosis, because additional swallows are likely to change the diagnosis in only 2% of patients.
authors.affiliation: Division of Gastroenterology and Hepatology, Medical University of South Carolina, 96 Jonathan Lucas Street, Charleston, SC 29425, USA.
authors.forename: Sajid
authors.initials: S
authors.lastname: Jalil
authors.forename: Monicca
authors.initials: M
authors.lastname: Sperandio
authors.forename: Radu
authors.initials: R
authors.lastname: Tutuian
authors.forename: Donald O
authors.initials: DO
authors.lastname: Castell
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003938:Diagnostic Techniques, Digestive System / Q000592:standards; D015154:Esophageal Motility Disorders / Q000175:diagnosis* / Q000503:physiopathology; D004947:Esophagus / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry / Q000379:methods; D008875:Middle Aged; D015203:Reproducibility of Results