Antepartum continuous epidural ropivacaine therapy reduces uterine artery vascular resistance in pre-eclampsia: a randomized, dose-ranging, placebo-controlled study.
BACKGROUND
No therapy is currently available to improve the reduced uteroplacental blood flow (UPBF) that characterizes pre-eclampsia. We hypothesized that sympathectomy induced by epidural local anaesthesia reduces uterine vascular resistance (which is inversely correlated with UPBF) in pre-eclampsia.


METHODS
Ten pregnant women between 24 and 32 weeks of gestation with pre-eclampsia and uterine artery flow abnormalities were randomized to antepartum continuous epidural therapy (ACET) or control. ACET was initiated by a 5 day dose-ranging trial (ACET-1) of 0.04, 0.06, 0.08, and 0.1% ropivacaine and saline placebo, each at 10 ml h(-1) for 24 h. Doses were randomized and double-blind. Doppler ultrasound indices of vascular resistance were assessed at baseline and after each 24 h dosing period in both uterine arteries. Subsequently, these ACET patients were administered 0.1% ropivacaine until delivery (ACET-2), with one additional randomized double-blind placebo day.


RESULTS
Five patients were randomized to ACET. In each patient, one uterine artery exhibited a dose-dependent reduction in vascular resistance (P=0.035), a response that returned to baseline following placebo (P<0.001). The contralateral uterine artery exhibited either increased vascular resistance or no change. In all cases, the uterine artery that responded to ACET had higher baseline resistance than its pair (P=0.043). Baseline right-left difference in resistance between paired uterine arteries was greatly diminished following ACET. Although ACET patients had a mean (sd) duration to delivery of 19 (9) days compared with control 2 (1) days (P=0.008), this should be interpreted with caution because of demographic differences between groups.


CONCLUSIONS
ACET reduces uterine artery resistance in pre-eclampsia <32 weeks. Uteroplacental re-distribution is a novel observation and warrants further investigation.
Ginosar
Y
Y
Department of Anesthesiology and Critical Care Medicine, Hadassah Hebrew University Medical Center, PO Box 12000, Ein Kerem, Jerusalem 91120, Israel. yginosar@netvision.net.il
Nadjari
M
M
Hoffman
A
A
Firman
N
N
Davidson
E M
EM
Weiniger
C F
CF
Rosen
L
L
Weissman
C
C
Elchalal
U
U
D000328:Adult; D000577:Amides / Q000008:administration & dosage / Q000494:pharmacology*; D000767:Anesthesia, Epidural / Q000379:methods; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D047109:Fetal Development / Q000187:drug effects; D006801:Humans; D011225:Pre-Eclampsia / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy; D011247:Pregnancy; D011295:Prenatal Care / Q000379:methods; D011446:Prospective Studies; D000077212:Ropivacaine; D013563:Sympathectomy, Chemical / Q000379:methods; D018608:Ultrasonography, Doppler / Q000379:methods; D016216:Ultrasonography, Prenatal / Q000379:methods; D014599:Uterus / Q000098:blood supply* / Q000000981:diagnostic imaging; D014655:Vascular Resistance / Q000187:drug effects*; D055815:Young Adult
D000577:Amides; D000779:Anesthetics, Local; D000077212:Ropivacaine