TY - JOUR
T1 - Ephedrine and phenylephrine for the treatment of maternal hypotension in a chronic sheep model of increased placental vascular resistance
AU - Erkinaro, Tiina
AU - Kavasmaa, T.
AU - Päkkilä, M.
AU - Acharya, G.
AU - Mäkikallio, K.
AU - Alahuhta, S.
AU - Räsänen, J.
N1 - Funding Information:
This study was supported by the Academy of Finland and The Research Foundation of Orion Corporation. We thank Pasi Ohtonen, MSc, for
PY - 2006/2
Y1 - 2006/2
N2 - Background. We hypothesized that ephedrine and phenylephrine are equal with respect to uterine and placental haemodynamics and fetal acid-base status after exposure to maternal hypoxaemia and hypotension in a chronic sheep model of increased placental vascular resistance (RUA). Methods. At 114-135 days gestation, chronically inst rumented fetal sheep underwent placental embolization leading to increased RUA. Twenty-four hours after embolization, the ewes were anaesthetized and randomized to receive boluses of ephedrine (n=7) or phenylephrine (n=6) for epidural-induced hypotension after maternal hypoxaemia. Uterine (QUtA) and placental (QUA) volume blood flows and uterine vascular resistance (RUtA) and RUA were recorded. Uterine (PIUtA) and umbilical artery (PIUA) pulsatility indices were obtained by Doppler ultrasonography. Fetal arterial blood samples were analysed for acid-base values and lactate concentrations. Results. During hypotension, QUtA, fetal pH, BE, and Po2 decreased whereas RUtA, PIUtA, RUA, and fetal lactate concentration increased. With ephedrine, QUtA, RUtA, PIUtA, RUA, and fetal P o2 returned to baseline. Fetal pH, BE, and lactate concentration did not change from hypotensive values. With phenylephrine, QUtA remained lower (P=0.007) and RUtA (P=0.007), PIUtA (P=0.013), and RUA (P=0.050) higher than at baseline. Fetal Po2 returned to baseline and fetal pH and BE did not change from hypotensive values. However, fetal lactate concentration increased further (mean difference 1.49, 95% confidence interval 0.72-2.26 mmol litre-1; P=0.004). Conclusions. In a chronic sheep model of increased placental vascular resistance, compared with ephedrine administration, phenylephrine administration was associated with impaired uterine and placental haemodynamics and increased fetal lactate concentrations.
AB - Background. We hypothesized that ephedrine and phenylephrine are equal with respect to uterine and placental haemodynamics and fetal acid-base status after exposure to maternal hypoxaemia and hypotension in a chronic sheep model of increased placental vascular resistance (RUA). Methods. At 114-135 days gestation, chronically inst rumented fetal sheep underwent placental embolization leading to increased RUA. Twenty-four hours after embolization, the ewes were anaesthetized and randomized to receive boluses of ephedrine (n=7) or phenylephrine (n=6) for epidural-induced hypotension after maternal hypoxaemia. Uterine (QUtA) and placental (QUA) volume blood flows and uterine vascular resistance (RUtA) and RUA were recorded. Uterine (PIUtA) and umbilical artery (PIUA) pulsatility indices were obtained by Doppler ultrasonography. Fetal arterial blood samples were analysed for acid-base values and lactate concentrations. Results. During hypotension, QUtA, fetal pH, BE, and Po2 decreased whereas RUtA, PIUtA, RUA, and fetal lactate concentration increased. With ephedrine, QUtA, RUtA, PIUtA, RUA, and fetal P o2 returned to baseline. Fetal pH, BE, and lactate concentration did not change from hypotensive values. With phenylephrine, QUtA remained lower (P=0.007) and RUtA (P=0.007), PIUtA (P=0.013), and RUA (P=0.050) higher than at baseline. Fetal Po2 returned to baseline and fetal pH and BE did not change from hypotensive values. However, fetal lactate concentration increased further (mean difference 1.49, 95% confidence interval 0.72-2.26 mmol litre-1; P=0.004). Conclusions. In a chronic sheep model of increased placental vascular resistance, compared with ephedrine administration, phenylephrine administration was associated with impaired uterine and placental haemodynamics and increased fetal lactate concentrations.
KW - Anaesthesia, obstetric
KW - Anaesthetic techniques, epidural
KW - Sympathetic nervous system, pharmacology, ephedrine
KW - Sympathetic nervous system, pharmacology, phenylephrine
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U2 - 10.1093/bja/aei305
DO - 10.1093/bja/aei305
M3 - Article
C2 - 16377647
AN - SCOPUS:31744435919
SN - 0007-0912
VL - 96
SP - 231
EP - 237
JO - British journal of anaesthesia
JF - British journal of anaesthesia
IS - 2
ER -