Epidural local anesthetics: a novel treatment for fetal growth retardation?
BACKGROUND
Chronically compromised uterine perfusion may lead to placental insufficiency and subsequent intrauterine growth restriction (IUGR). Various therapeutic approaches (e.g. vasodilators, low-dose aspirin, intravenous glucose infusion, and hemodilution) are often of limited efficacy. Local anesthetics have been shown to improve placental blood flow in pre-eclamptic women. We hypothesized that epidural administration of local anesthetics might improve outcome in IUGR independent of the underlying cause. In preparation for a clinical trial to test this hypothesis, we performed a pilot study in 10 patients.


METHODS
After approval of the study protocol, 10 pregnant women presenting with oligohydramnios and IUGR were included in the study. In addition to our standard protocol (magnesium, glucose, betamethasone), each patient received an epidural catheter (T10/T12) with continuous infusion of bupivacaine 0.175% at a rate of 5 ml/h. Uteroplacental circulation was monitored by Doppler sonography and the amount of amniotic fluid was estimated daily.


RESULTS
Epidural insertion and infusion was performed without complications. Four patients continued to deteriorate rapidly, amniotic fluid volume did not change and uterine artery pulsatility index (PI) tended to increase. In the remaining 6 patients the clinical status stabilized, amniotic fluid volume tended to increase and uterine artery PI tended to decrease during treatment. This improvement was associated with a prolonged interval to cesarean section and increased infant birth weight.


CONCLUSIONS
Our data suggest that, even if the underlying cause of IUGR is not pre-eclampsia, epidural local anesthetic administration might improve placental blood flow and be beneficial in a subgroup of patients. A clinical trial to test this hypothesis appears warranted.
Strümper
D
D
Department of Anesthesiology and Intensive Care Medicine, University of Munster, Germany.
Louwen
F
F
Durieux
M E
ME
Gramke
H F
HF
Stuessel
J
J
Marcus-Soekarman
D
D
Van Aken
H
H
Marcus
M A E
MA
D000328:Adult; D000653:Amniotic Fluid / Q000378:metabolism; D000767:Anesthesia, Epidural; D000779:Anesthetics, Local / Q000627:therapeutic use*; D001158:Arteries / Q000503:physiopathology; D001724:Birth Weight; D002045:Bupivacaine / Q000627:therapeutic use*; D002585:Cesarean Section; D005260:Female; D005317:Fetal Growth Retardation / Q000150:complications / Q000188:drug therapy*; D006801:Humans; D016104:Oligohydramnios / Q000150:complications / Q000378:metabolism; D010865:Pilot Projects; D011247:Pregnancy; D011674:Pulse; D013997:Time Factors; D014599:Uterus / Q000098:blood supply
D000779:Anesthetics, Local; D002045:Bupivacaine