title: Variation of the anal resting pressure induced by postexpiratory apnea effort in patients with constipation.
abstract: BACKGROUND
  Intestinal constipation--a common symptom among the general population--is more frequent in women. It may be secondary to an improper diet or organic or functional disturbances, such as dyskinesia of the pelvic floor. This is basically characterized by the absence of relaxation or paradoxical contraction of the pelvic floor and anal sphincter during evacuation.
  
  
  OBJECTIVE
  To analyze, by manometric data, the anal pressure variation at rest, during evacuation effort by using the Valsalva maneuver and forced post-expiratory apnea in subjects with secondary constipation.
  
  
  METHODS
  Twenty-one patients (19 females--90.4%) with a mean age of 47.5 years old (23-72) were studied. The diagnosis was performed using anorectal manometry, with a catheter containing eight channels disposed at the axial axis, measuring the proximal (1) and distal (2) portions of the anal orifice. The elevation of the pressure values in relation to the resting with the evacuation effort was present in all patients. The Agachan score was used for clinical evaluation of constipation. The variables studied were: mean anal pressure of the anal orifice for 20 seconds at rest, the effort of evacuation using Valsalva maneuver and the effort of evacuation during apnea after forced expiration, as well as the area under the curve of the manometric tracing at moments Valsalva and apnea.
  
  
  RESULTS
  The analysis of the mean values of the anal pressure variation at rest evidenced difference between proximal and distal channels (P = 0.007), independent of the moment and tendency to differ during moments Valsalva and apnea (P = 0.06). The mean of values of the area under the manometric tracing curve showed differences between moments Valsalva and apnea (P = 0.0008), either at the proximal portion or at the distal portion of the anal orifice.
  
  
  CONCLUSIONS
  The effort of evacuation associated with postexpiratory apnea, when compared with the effort associated with the Valsalva maneuver, provides lower elevation of anal pressure at rest by the parameter area under the curve.
authors.affiliation: Department of Surgery, Faculty of Medical Sciences, University of Campinas FCM, UNICAMP. thaishbenetti@hotmail.com
authors.forename: Thaís Helena
authors.initials: TH
authors.lastname: Benetti
authors.forename: Maria Fernanda
authors.initials: MF
authors.lastname: Santos
authors.forename: Melissa Eichenberger Alves
authors.initials: ME
authors.lastname: Mergulhão
authors.forename: João José
authors.initials: JJ
authors.lastname: Fagundes
authors.forename: Maria de Lourdes Setsuko
authors.initials: Mde L
authors.lastname: Ayrizono
authors.forename: Cláudio Saddy Rodrigues
authors.initials: CS
authors.lastname: Coy
mesh_terms: D000328:Adult; D000368:Aged; D001003:Anal Canal / Q000503:physiopathology*; D001049:Apnea / Q000503:physiopathology; D003248:Constipation / Q000503:physiopathology*; D003672:Defecation / Q000502:physiology*; D045853:Exhalation / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry; D008875:Middle Aged; D011312:Pressure; D014636:Valsalva Maneuver; D055815:Young Adult