The effects of continuous epidural analgesia on Doppler velocimetry of uterine arteries during different periods of labour analgesia.
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.
Chen
L K
LK
Department of Anesthesiology, National Taiwan University Hospital, College of Medicine, Taipei, Taiwan.
Lin
C J
CJ
Huang
C H
CH
Wang
M H
MH
Lin
P L
PL
Lee
C N
CN
Sun
W Z
WZ
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
D000779:Anesthetics, Local; D002045:Bupivacaine