The effects of extracorporeal membrane oxygenation on hypoxic fetal lambs

目的：本研究的目的是确定静脉动脉或静脉静脉体外膜氧合（ECMO）技术在子宫内支持胎儿氧合的适用性。研究设计：采用带离心泵的ECMO系统，对15例妊娠125 ~ 133天长期使用ECMO设备的胎羔进行治疗，且胎盘循环完整。血液通过插入右心房的12fr双腔导管获得。氧合后，血液通过颈动脉单腔导管（VA ECMO）或右心房另一腔导管（VV ECMO）回流。通过降低母体FiO2实验产生胎儿缺氧后，VA ECMO开始维持胎儿氧合30分钟，切换到VV ECMO。我们比较了两种ECMO方式下胎儿颅颈动脉和腋窝动脉的血气。测定胎儿血浆ANP、儿茶酚胺、AVP和皮质醇。此外，我们…More测定了含氧血流在胎盘循环的各个时期的分布完整的非放射性彩色微球。结果：VA或VV ECMO时双腔导管ECMO血流量约为50 ~ 60ml /min。胎儿颅颈动脉pO2通过降低母亲FiO2而降低。维持VA ECMO或VV ECMO后，pO2恢复到有利胎儿酸中毒的对照水平。在实验过程中，胎儿心率和血压没有明显变化。胎儿血浆儿茶酚胺、AVP和皮质醇升高，而胎儿血浆ANP降低。胎儿羔羊中VV ECMO比VA ECMO更接近正常的完整胎盘-胎儿血流分布。结论：在母体缺氧时，VA或VV ECMO可维持胎儿正常氧合，应将氧合血回流至胎儿右心房，维持胎儿心脏氧合和胎儿生理循环。本研究表明，VV ECMO能有效地维持胎儿氧合，对缺氧胎羊羔的创伤较小。少

Objective: The purpose of this study was to determine the applicability of using venoarterial or venovenous extracorporeal membrane oxygenation (ECMO) techniques to support fetal oxygenation in utero.Study Design: An ECMO system with centrifugal pump was applied to fifteen chronically instrumented fetal lambs, ranging from 125 to 133 days of gestation, with the placental circulation intact. Blood was obtained through a 12 Fr. double lumen catheter inserted into the right atrium. After oxygenation the blood was returned through a 9 Fr. single lumen catheter in carotid artery (VA ECMO) or the other lumen in the right atrium (VV ECMO). After fetal hypoxia was experimentally produced by reducing FiO2 of the mother, the VA ECMO started to maintain the fetal oxygenation for 30 minutes, and switched to the VV ECMO. We compared fetal blood gases of cranial carotid and axillar arteries with the both routes of ECMO. We also measured fetal plasma ANP, Catecholamine, AVP and Cortisol. Moreover, we … More determined the distribution of oxygenated blood flow in each period during placental circulation intact by non-radioactive colored microspheres.Results: The ECMO blood flow rate through the double lumen catheter during VA or VV ECMO ranged at approximately 50-60 ml/min. Fetal cranial carotid arterial pO2 was decreased by reducing FiO2 of the mother. After maintaining of VA ECMO or VV ECMO, the pO2 was recovered to the control level under advantaging fetal acidosis. The fetal heart rate and blood pressure were not significantly altered during the experiments. Fetal plasma Catecholamine, AVP and Cortisol increased through the experiments, however fetal plasma ANP decreased during the VV ECMO. The VV ECMO more closely approximated normal intact placental-fetal blood flow distribution than the VA ECMO in fetal lambs.Conclusion: The VA or VV ECMO maintained normal fetal oxygenation during maternal hypoxia The oxygenated blood should be returned to fetal right atrium for maintenance of fetal cardiac oxygenation and fetal physiological circulation. This study indicated that the VV ECMO could maintain fetal oxygenation effectively and less traumatically on hypoxic fetal lambs. Less