title: What is the variability in urodynamic parameters with position change in children? Analysis of a prospectively enrolled cohort.
abstract: OBJECTIVE
  Insufficient data are available regarding the effect of patient position on urodynamic parameters and diagnoses in children. We report on a cohort of pediatric patients, comparing the results of serial urodynamic studies to determine the variability between the supine and sitting positions.
  
  
  METHODS
  Children referred for urodynamic evaluation were prospectively enrolled based on the ability to tolerate position change. Consecutive studies in supine and sitting positions were performed during a single session by the same nursing team. Volume infused and infusion rate did not differ with position change.
  
  
  RESULTS
  A total of 48 children were enrolled in the study. Mean patient age was 10.4 years. No statistically significant difference was noted for maximum cystometric capacity, detrusor leak point pressures or pressure specific volumes at 20 and 30 cm water between the supine and sitting positions. Statistically significant lower values were found for the volume of first sensation and volume at which detrusor overactivity was first detected (p <0.05), with a trend toward significance for abdominal or Valsalva leak point pressure. Statistically significant differences were also noted with position changes in regard to detection of detrusor overactivity and incontinence episodes (p <0.05).
  
  
  CONCLUSIONS
  In our study population no significant differences were detected in several urodynamic parameters with position change, suggesting that clinically valid conclusions can be obtained by performing the study in either position. Studies in the sitting position allow for increased detection of detrusor overactivity and incontinence, thus, being favored over the supine position if well tolerated by the child.
authors.affiliation: Division of Urology, Hospital for Sick Children and University of Toronto, Toronto, Ontario, Canada.
authors.forename: Armando J
authors.initials: AJ
authors.lastname: Lorenzo
authors.forename: M Chad
authors.initials: MC
authors.lastname: Wallis
authors.forename: Anthony
authors.initials: A
authors.lastname: Cook
authors.forename: Angela
authors.initials: A
authors.lastname: Buffett-Fairen
authors.forename: Dalia
authors.initials: D
authors.lastname: Bozic
authors.forename: Darius J
authors.initials: DJ
authors.lastname: Bägli
authors.forename: Antoine E
authors.initials: AE
authors.lastname: Khoury
authors.forename: Joao L
authors.initials: JL
authors.lastname: Pippi Salle
mesh_terms: D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D011187:Posture; D011312:Pressure; D011336:Probability; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D001743:Urinary Bladder / Q000502:physiology; D053201:Urinary Bladder, Overactive / Q000503:physiopathology*; D014554:Urination / Q000502:physiology*; D014563:Urodynamics / Q000502:physiology*