title: Upper esophageal sphincter resting pressure varies during esophageal manometry.
abstract: BACKGROUND
  The upper esophageal sphincter is composed of striated muscle. The stress of intubation and the need to inhibit dry swallows during an esophageal manometry test may lead to variations in basal pressure of this sphincter. Upper esophageal sphincter is usually only studied at the final part of the test. Was observed during the performance of high resolution manometry that sphincter pressure may vary significantly over the course of the test.
  
  
  OBJECTIVE
  To evaluate the variation of the resting pressure of the upper esophageal sphincter during high resolution manometry.
  
  
  METHODS
  Was evaluated the variation of the basal pressure of the upper esophageal sphincter during high resolution manometry. Were reviewed the high resolution manometry tests of 36 healthy volunteers (mean age 31 years, 55% females). The basal pressure of the upper esophageal sphincter was measured at the beginning and at the end of a standard test.
  
  
  RESULTS
  The mean time of the test was eight minutes. The basal pressure of the upper esophageal sphincter was 100 mmHg at the beginning of the test and 70 mmHg at the end (p<0.001). At the beginning, one patient had hypotonic upper esophageal sphincter and 14 hypertonic. At the end of the test, one patient had hypotonic upper esophageal sphincter (same patient as the beginning) and seven hypertonic upper esophageal sphincter.
  
  
  CONCLUSIONS
  A significant variation of the basal pressure of the upper esophageal sphincter was observed in the course of high resolution manometry. Probably, the value obtained at the end of the test may be more clinically relevant.
authors.affiliation: Department of Surgery, Paulista School of Medicine, Federal University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Daniel Tavares
authors.initials: DT
authors.lastname: Rezende
authors.affiliation: Department of Surgery, Paulista School of Medicine, Federal University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Fernando A M
authors.initials: FA
authors.lastname: Herbella
authors.affiliation: Department of Surgery, Paulista School of Medicine, Federal University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Luciana C
authors.initials: LC
authors.lastname: Silva
authors.affiliation: Department of Surgery, Paulista School of Medicine, Federal University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Sebastião
authors.initials: S
authors.lastname: Panocchia-Neto
authors.affiliation: Department of Surgery, University of Chicago, Chicago, IL, USA.
authors.forename: Marco G
authors.initials: MG
authors.lastname: Patti
mesh_terms: D000328:Adult; D049631:Esophageal Sphincter, Upper / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry; D011312:Pressure