title: Is Urodynamic Study a Good Witness to the Progression of Ketamine-Associated Cystitis?
abstract: OBJECTIVE
  Ketamine abuse may cause variable lower urinary tract symptoms and severe cystitis. In this study, we evaluated the relevance of urodynamic parameters according to the dose and duration of ketamine use and investigate the value of urodynamic studies in determining the severity of ketamine-associated cystitis (KC).
  
  
  METHODS
  The urodynamic study results of 30 patients with KC between January 2009 and December 2012 were analyzed retrospectively. All patients had been diagnosed based on their history and clinical features before urodynamic investigations. Cystoscopy was performed to confirm the diagnosis and measure the maximum anesthetic bladder bladder capacity (MBC) (under spinal anesthesia).
  
  
  RESULTS
  The mean (± standard deviation) age of patients with KC was 22.0 ± 3.3 years. The mean duration of ketamine abuse was 39.0 ± 20.8 months. Maximum cystometric capacity was 115 ± 66.6 mL. Seventy-five percent of patients had a high maximal urethral closure pressure (MUCP) (> 90 cmH2 O). There was no significant difference of urodynamic parameters between the high-dose (≥ 5 gm/day) and low-dose groups (< 5 gm/day) or the long-duration (≥ 3 years) and short-duration (< 3 years) groups. However, the MBC was significantly lower in high-dose and long-duration groups compared to the low-dose and short-duration groups (191.3 ± 68.5 vs. 299.0 ± 99 mL; P = 0.01; 219.0 ± 59.7 vs. 325.5 ± 104.5 mL; P = 0.002).
  
  
  CONCLUSIONS
  The urodynamic test results help diagnose KC, but may not be useful in determining the severity of the disease. The MBC measured under anesthesia may be a better predictor of the disease progression in KC.
authors.affiliation: Division of Urology, Department of Surgery, Tri-Service General Hospital, Taipei, Taiwan.
authors.forename: Po-Wei
authors.initials: PW
authors.lastname: Huang
authors.affiliation: Division of Urology, Department of Surgery, Tri-Service General Hospital, Taipei, Taiwan.
authors.forename: Sheng-Tang
authors.initials: ST
authors.lastname: Wu
authors.affiliation: Division of Urology, Department of Surgery, Tri-Service General Hospital, Taipei, Taiwan.
authors.forename: Chih-Wei
authors.initials: CW
authors.lastname: Tsao
authors.affiliation: Division of Urology, Department of Surgery, Tri-Service General Hospital, Taipei, Taiwan.
authors.forename: Shou-Hung
authors.initials: SH
authors.lastname: Tang
authors.affiliation: Division of Urology, Department of Surgery, Tri-Service General Hospital, Taipei, Taiwan.
authors.forename: Tai-Lung
authors.initials: TL
authors.lastname: Cha
authors.affiliation: Division of Urology, Department of Surgery, Tri-Service General Hospital, Taipei, Taiwan.
authors.forename: Guang-Huan
authors.initials: GH
authors.lastname: Sun
authors.affiliation: Division of Urology, Department of Surgery, Tri-Service General Hospital, Taipei, Taiwan.
authors.forename: Dah-Shyong
authors.initials: DS
authors.lastname: Yu
authors.affiliation: Division of Urology, Department of Surgery, Tri-Service General Hospital, Taipei, Taiwan.
authors.forename: Sheng-Yran
authors.initials: SY
authors.lastname: Chang
authors.affiliation: Division of Urology, Department of Surgery, Tri-Service General Hospital, Taipei, Taiwan.
authors.forename: En
authors.initials: E
authors.lastname: Meng
keywords: cystitis; ketamine; maximum anesthetic bladder capacity; urodynamics