Effects of ephedrine and phenylephrine on uterine and placental circulations and fetal outcome following fetal hypoxaemia and epidural-induced hypotension in a sheep model

Tiina Erkinaro, K. Mäkikallio, T. Kavasmaa, S. Alahuhta, Juha Rasanen

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

Background. Recent studies support the use of α-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 (PlUtA) and umbilical artery (PlUA) pulsatility indices were obtained by Doppler ultrasonography. Results. Ephedrine increased QUtA and decreased RUtA and PlUtA 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 PlUtA decreased to baseline level. PlUA 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.

Original languageEnglish (US)
Pages (from-to)825-832
Number of pages8
JournalBritish Journal of Anaesthesia
Volume93
Issue number6
DOIs
StatePublished - Dec 2004
Externally publishedYes

Fingerprint

Controlled Hypotension
Placental Circulation
Ephedrine
Phenylephrine
Sheep
Mothers
Umbilical Arteries
Blood Volume
Lactic Acid
Umbilicus
Doppler Ultrasonography
Uterine Artery
Pregnancy
Conduction Anesthesia
Fetal Blood
Ultrasonics
Vascular Resistance
Starch
Hypotension
Hypoxia

Keywords

  • Anaesthesia, obstetric
  • Anaesthetic techniques, epidural
  • Sympathetic nervous system, pharmacology, ephedrine
  • Sympathetic nervous system, pharmacology, phenylephrine

ASJC Scopus subject areas

  • Anesthesiology and Pain Medicine

Cite this

Effects of ephedrine and phenylephrine on uterine and placental circulations and fetal outcome following fetal hypoxaemia and epidural-induced hypotension in a sheep model. / Erkinaro, Tiina; Mäkikallio, K.; Kavasmaa, T.; Alahuhta, S.; Rasanen, Juha.

In: British Journal of Anaesthesia, Vol. 93, No. 6, 12.2004, p. 825-832.

Research output: Contribution to journalArticle

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abstract = "Background. Recent studies support the use of α-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 (PlUtA) and umbilical artery (PlUA) pulsatility indices were obtained by Doppler ultrasonography. Results. Ephedrine increased QUtA and decreased RUtA and PlUtA 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 PlUtA decreased to baseline level. PlUA 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.",
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T1 - Effects of ephedrine and phenylephrine on uterine and placental circulations and fetal outcome following fetal hypoxaemia and epidural-induced hypotension in a sheep model

AU - Erkinaro, Tiina

AU - Mäkikallio, K.

AU - Kavasmaa, T.

AU - Alahuhta, S.

AU - Rasanen, Juha

PY - 2004/12

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N2 - Background. Recent studies support the use of α-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 (PlUtA) and umbilical artery (PlUA) pulsatility indices were obtained by Doppler ultrasonography. Results. Ephedrine increased QUtA and decreased RUtA and PlUtA 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 PlUtA decreased to baseline level. PlUA 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.

AB - Background. Recent studies support the use of α-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 (PlUtA) and umbilical artery (PlUA) pulsatility indices were obtained by Doppler ultrasonography. Results. Ephedrine increased QUtA and decreased RUtA and PlUtA 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 PlUtA decreased to baseline level. PlUA 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.

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KW - Anaesthetic techniques, epidural

KW - Sympathetic nervous system, pharmacology, ephedrine

KW - Sympathetic nervous system, pharmacology, phenylephrine

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