Pulmonary Shunting during Venovenous Bypass

抄録

Using mongrel dogs, an experimental study was performed to investigate Qs/Qt during v-v bypass with or without oxygenation. During bypass, the systemic circulation was maintained under constant conditions, while bypass flow rate, Svo₂ and Pvco₂ varied independently.
The results were as follows:
1) In dogs undergoing v-v bypass without oxygenation, Qs/Qt and A-aDO₂ increased markedly in proportion to bypass flow in animals receiving blood infusion into the right ventricle, but a remarkable increase was not seen in animals receiving blood infusion into the right atrium. The pulmonary artery waveform appeared to influence Qs/Qt.
2) A significant positive correlation was found between Qs/Qt and Svo₂. A-aDO₂ showed no correlation to Svo₂.
3) The Qs/Qt showed no remarkable changes despite significant changes in Pvco₂ (from 22 to 96mmHg).
4) With regard to Qs/Qt and Svo₂, it may be proper to perform v-v bypass at a flow rate of 30ml/Kg/min with blood infusion into the right atrium.