BJA Advance Access originally published online on October 1, 2004
British Journal of Anaesthesia 2004 93(6):825-832; doi:10.1093/bja/aeh273
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
© The Board of Management and Trustees of the British Journal of Anaesthesia 2004
Effects of ephedrine and phenylephrine on uterine and placental circulations and fetal outcome following fetal hypoxaemia and epidural-induced hypotension in a sheep model
1 Department of Anaesthesiology and 2 Department of Obstetrics and Gynaecology, University Hospital of Oulu, PO Box 21, FIN-90029 OYS, Finland
* Corresponding author. E-mail: tiina.erkinaro{at}pp.fimnet.fi
Background. Recent studies support the use of 
-agonists during regional anaesthesia in uncomplicated term pregnancies. We hypothesized that ephedrine and phenylephrine, administered for maternal hypotension following fetal hypoxaemia, are equal in respect of fetal outcome.
Methods. At 117–132 days gestation, chronically instrumented, anaesthetized and mechanically ventilated ewes were randomized to receive boluses of ephedrine (n=9) or phenylephrine (n=8) for maternal epidural-induced hypotension after a period of fetal hypoxaemia. Uterine (QUtA) and placental (QUA) volume blood flows were measured with perivascular transit-time ultrasonic flow probes, and uterine (RUtA) and placental (RUA) vascular resistances were computed from volume blood flows and maternal and fetal mean arterial pressures. Uterine (PIUtA) and umbilical artery (PIUA) pulsatility indices were obtained by Doppler ultrasonography.
Results. Ephedrine increased QUtA and decreased RUtA and PIUtA from a hypotensive to baseline level and had no significant effect on umbilical circulation. With phenylephrine, QUtA remained lower (P=0.011) and RUtA higher (P=0.043) than at baseline, although PIUtA decreased to baseline level. PIUA increased from baseline with phenylephrine (P=0.007), whereas QUA decreased (P=0.050). Maternal volume expansion with hydroxyethyl starch decreased RUtA significantly irrespective of the vasopressor used. There were no significant differences in fetal blood gas values or lactate concentrations between the ephedrine and phenylephrine groups.
Conclusions. Despite the more favourable effects on uterine and placental circulations of ephedrine over phenylephrine, no significant differences in fetal acid–base status or lactate concentrations were observed.
Presented in part at the 10th Anniversary Meeting of the European Society of Anaesthesiologists, Nice, France, 6–9 April, 2002.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  S. Visalyaputra Is Ephedrine the Best Vasopressor for Treating Spinal Anesthesia-Induced Hypotension in Patients with Pre-Eclampsia? Anesth. Analg., December 1, 2006; 103(6): 1584 - 1585. [Full Text] [PDF]
|
|
|
|
 |
|
 Ephedrine and phenylephrine for treatment of maternal hypotension. Br. J. Anaesth., June 1, 2006; 96(6): 804 - 805. [Full Text] [PDF]
|
|
|
|
|
|
T. Erkinaro, T. Kavasmaa, M. Pakkila, G. Acharya, K. Makikallio, S. Alahuhta, and J. Rasanen Ephedrine and phenylephrine for the treatment of maternal hypotension in a chronic sheep model of increased placental vascular resistance Br. J. Anaesth., February 1, 2006; 96(2): 231 - 237. [Abstract] [Full Text] [PDF]
|
|