title: The effects of continuous epidural analgesia on Doppler velocimetry of uterine arteries during different periods of labour analgesia.
abstract: BACKGROUND
  The transient effects of epidural bupivacaine 0.25-0.5% on the Doppler velocimetry of umbilical and uterine arteries had been reported, but the effects of continuous lower dose epidural bupivacaine (0.05-0.1%) infusion for labour analgesia have never been reported. In this study, we evaluated the effects of continuous epidural bupivacaine 0.075% on the Doppler velocimetry of uterine arteries.
  
  
  METHODS
  Twenty pregnant women for labour analgesia received continuous epidural bupivacaine 0.075% infusion. We used a 4-MHz continuous-wave Doppler probe (Multigon 500A) with a 200 Hz thump filter to detect uterine blood flow velocity. We recorded the velocimetry data for uterine relaxation and contraction during five time periods: pre-epidural insertion, 1, 2, and 4 h post-epidural infusion, and after delivery of fetus.
  
  
  RESULTS
  Our data showed that the velocimetric indices of uterine vascular resistance were significantly increased 1, 2, and 4 h after epidural infusion when compared with the pre-epidural level; these returned to the baseline after delivery.
  
  
  CONCLUSIONS
  Continuous epidural analgesia with bupivacaine 0.075% increases the resistance of uterine artery and therefore possibly reduces the uterine blood flow.
authors.affiliation: Department of Anesthesiology, National Taiwan University Hospital, College of Medicine, Taipei, Taiwan.
authors.forename: L K
authors.initials: LK
authors.lastname: Chen
authors.forename: C J
authors.initials: CJ
authors.lastname: Lin
authors.forename: C H
authors.initials: CH
authors.lastname: Huang
authors.forename: M H
authors.initials: MH
authors.lastname: Wang
authors.forename: P L
authors.initials: PL
authors.lastname: Lin
authors.forename: C N
authors.initials: CN
authors.lastname: Lee
authors.forename: W Z
authors.initials: WZ
authors.lastname: Sun
mesh_terms: D015360:Analgesia, Epidural / Q000379:methods*; D016362:Analgesia, Obstetrical / Q000379:methods*; D000779:Anesthetics, Local / Q000494:pharmacology*; D001158:Arteries / Q000187:drug effects / Q000502:physiology; D001783:Blood Flow Velocity / Q000187:drug effects; D002045:Bupivacaine / Q000494:pharmacology*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D017078:Laser-Doppler Flowmetry; D011247:Pregnancy; D012039:Regional Blood Flow / Q000187:drug effects; D014599:Uterus / Q000098:blood supply*; D014655:Vascular Resistance / Q000187:drug effects
chemical_list: D000779:Anesthetics, Local; D002045:Bupivacaine