title: The effects of thoracic epidurally administered drugs on urethral sphincter function in women: a pooled analysis.
abstract: OBJECTIVE
  Thoracic epidural analgesia (TEA) has been shown to inhibit detrusor activity in patients undergoing open renal surgery, resulting in clinically relevant post-void residuals. However, the impact of different epidural drug mixtures on urethral sphincter function is not completely elucidated.
  
  
  METHODS
  Pooled analysis of an open observational study and a double-blind randomized trial.
  
  
  METHODS
  Single tertiary centre.
  
  
  METHODS
  Twenty-eight women without lower urinary tract symptoms and post-void residual <100 mL, who underwent open renal surgery with TEA.
  
  
  METHODS
  Pooling results in three groups with different epidural regimens (7 with bupivacaine 0.125%, 8 with bupivacaine 0.125% and fentanyl 2 μg/mL, and 13 with bupivacaine 0.1% plus fentanyl 2 μg/mL and epinephrine 2 μg/mL). All women underwent urethral pressure measurements before TEA and during TEA 2-3 days postoperatively. All patients received a TEA placed at the insertion site interspace T 8-9.
  
  
  RESULTS
  Maximum urethral closure pressure at rest decreased significantly during TEA with bupivacaine alone (median 70 cm H2 O [interquartile range 66-76] to 43 [43-65], P = 0.031) and with bupivacaine/fentanyl/epinephrine (75 cm H2 O [68-78] to 56 [52-75], P = 0.028), whereas with bupivacaine/fentanyl, no significant change could be detected (74 [51-88] vs 67 [46-70], P = 0.156). In all groups, functional profile length at rest was not influenced during TEA.
  
  
  CONCLUSIONS
  TEA with bupivacaine and the addition of fentanyl and epinephrine appears to decrease maximum urethral closure pressure at rest in women. The addition of fentanyl alone to bupivacaine may reduce this effect. Thus, the TEA effect on urethral sphincter function seems to depend on the drug mixture administered.
authors.affiliation: Department of Anaesthesiology and Pain Therapy, University Hospital Bern, Bern, Switzerland. patrick.wuethrich@insel.ch
authors.forename: Patrick Y
authors.initials: PY
authors.lastname: Wuethrich
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Kessler
authors.forename: Fiona C
authors.initials: FC
authors.lastname: Burkhard
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008875:Middle Aged; D015360:Analgesia, Epidural / Q000009:adverse effects; D018686:Anesthetics, Intravenous; D000779:Anesthetics, Local / Q000009:adverse effects; D002045:Bupivacaine / Q000009:adverse effects; D004311:Double-Blind Method; D005283:Fentanyl; D007268:Injections, Epidural; D007668:Kidney / Q000601:surgery; D009407:Nerve Block; D010147:Pain Measurement; D011183:Postoperative Complications / Q000453:epidemiology; D016896:Treatment Outcome; D014521:Urethra / Q000187:drug effects; D014563:Urodynamics / Q000187:drug effects; D013520:Urologic Surgical Procedures / Q000379:methods; D064887:Observational Studies as Topic; D016032:Randomized Controlled Trials as Topic
chemical_list: D018686:Anesthetics, Intravenous; D000779:Anesthetics, Local; D002045:Bupivacaine; D005283:Fentanyl
keywords: Epidural Analgesia; Urethral Sphincter Function