Placental compliance during fetal extracorporeal circulation.

@article{Assad2001PlacentalCD,
  title={Placental compliance during fetal extracorporeal circulation.},
  author={Renato Samy Assad and Fan Yan Lee and Frank Louis Hanley},
  journal={Journal of applied physiology},
  year={2001},
  volume={90 5},
  pages={
          1882-6
        }
}
The fetus requires large amounts of volume when weaning from cardiac bypass. This suggests that placental vasculature can act as a large capacitor in the fetal circulation. To assess placental compliance of fetal lambs, seven isolated in situ lamb placentas were placed on extracorporeal circulation. Umbilical artery blood flow was varied from 0 to 350 ml. min(-1). kg fetal wt(-1). Because the extracorporeal circuit is a closed system, volume changes in the placenta induced by umbilical artery… 
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References

SHOWING 1-10 OF 26 REFERENCES

Extracorporeal circulation in the isolated in situ lamb placenta: hemodynamic characteristics.

The clinical implication is that decreased placental flow and pressure on CPB may lead to a vicious cycle, resulting in further impairment of placental perfusion and respiratory gas exchange, and hypothermia promotes this impairment.

Exclusion of the placenta during fetal cardiac bypass augments systemic flow and provides important information about the mechanism of placental injury.

The Circulation of the Fetus in Utero: Methods For Studying Distribution of Blood Flow, Cardiac Output And Organ Blood Flow

Experimental evidence is provided that (1) there is no significant recirculation of microspheres, (2) the distribution of spheres is proportional to flow, and (3) circulatory physiology is not altered by injection of spheres.

Long-term survivors of fetal cardiac bypass in lambs.

Fetal vascular responses to prostacyclin.

Prostaglandin synthesis inhibition prevents placental dysfunction after fetal cardiac bypass.

High-dose steroids prevent placental dysfunction after fetal cardiac bypass.

Inhibition of the fetal stress response improves cardiac output and gas exchange after fetal cardiac bypass.

Determination of Fetal, Placental and Neonatal Blood Volumes in the Sheep

A sheep preparation was developed for studying fetoplacental and neonatal blood volumes using isotope dilution techniques, and placental blood volume was independent of fetal weight and remained relatively constant during the last fourth of gestation.

Fetal placental vascular responses to prostacyclin after angiotensin II-induced vasoconstriction.

It is concluded that angiotensin II causes fetal hypertension and renal and intestinal vasoconstriction, which are reversed by prostacyclin.