Murata Y, Fujimori K, Quilligan E J, Nagata N, Ibara S, Hirano T, Kamimura T
Division of Maternal and Fetal Medicine, Department of Obstetrics and Gynecology, University of California, Irvine, Orange, CA 92668, USA.
Am J Obstet Gynecol. 1996 Mar;174(3):864-70. doi: 10.1016/s0002-9378(96)70314-9.
The purpose of this study was to determine the degree of cardiac oxygenation produced by different routes of extracorporeal membrane oxygenation in fetal lambs submerged in warm saline solution.
Seven fetal lambs ranging in age from 113 to 133 days of gestation were delivered by cesarean section and oxygenated with extracorporeal membrane oxygenation. To maintain the patency of the ductus arteriosus, prostaglandin E1 was continuously infused intravenously to the fetus. Initially the extracorporeal membrane oxygenation route was from the right atrium to the carotid artery. Then the extracorporeal membrane oxygenation route was changed to flow from the right atrium to the umbilical vein. The fetus was kept in a warm saline solution bath, and the fetal circulation was maintained. Extracorporeal membrane oxygenation flow ranged between 100 and 200 ml/min throughout the experiment. Simultaneous blood samples were taken during both types of extracorporeal membrane oxygenation from the following points in the fetal circulation: premembrane (least oxygenated blood leaving the fetus from the right atrium), postmembrane (oxygenated blood returning to the fetus), the carotid artery, and the left ventricle. The respiratory gases and pH of each sample were measured. Six fetuses received nonradioactive colored microspheres injected into the oxygenated blood returning to the fetus flow before returning to the fetuses during both types of extracorporeal membrane oxygenation. After the animals were killed, microspheres were counted in the myocardium separately taken from the right and left atria and the right and left ventricles to determine cardiac blood flow.
During right atrium to carotid artery extracorporeal membrane oxygenation, left ventricle PO2 remained low as postmembrane PO2 increased; these values were not significantly correlated (r = 0.234, p = 0.61). During right atrium to umbilical vein extracorporeal membrane oxygenation, left ventricle and postmembrane PO2 exhibited a significant positive correlation (r = 0.855, p = 0.014). When the extracorporeal membrane oxygenation route was switched from the right atrium to carotid artery to the right atrium to umbilical vein, there was a significant increase in left ventricle PO2 and a decrease in left ventricle PCO2, whereas the respiratory gases and pH remained unchanged at other sites in the circulation. Microsphere counts were consistently higher during right atrium to umbilical vein extracorporeal membrane oxygenation than during right atrium to carotid artery extracorporeal membrane oxygenation in all four samples from different parts of myocardium (p < 0.001 by paired t test).
More effective cardiac oxygenation is provided by right atrium to umbilical vein extracorporeal membrane oxygenation than by right atrium to carotid artery extracorporeal membrane oxygenation.
本研究的目的是确定在浸泡于温盐溶液中的胎羊中，不同体外膜肺氧合（ECMO）途径所产生的心脏氧合程度。
7只妊娠年龄在113至133天的胎羊通过剖宫产娩出，并接受ECMO氧合。为维持动脉导管通畅，持续静脉内给胎儿输注前列腺素E1。最初ECMO途径是从右心房至颈动脉。然后将ECMO途径改为从右心房至脐静脉。胎儿置于温盐溶液浴中，并维持胎儿循环。在整个实验过程中，ECMO流量在100至200ml/分钟之间。在两种类型的ECMO期间，同时从胎儿循环中的以下部位采集血样：膜前（从右心房离开胎儿的氧含量最低的血液）、膜后（返回胎儿的氧合血液）、颈动脉和左心室。测量每个样本的呼吸气体和pH值。在两种类型的ECMO期间，6只胎儿在返回胎儿的氧合血液流中注入非放射性彩色微球，然后再返回胎儿。动物处死后，分别从右心房、左心房、右心室和左心室获取心肌，对微球进行计数以确定心脏血流量。
在右心房至颈动脉的ECMO期间，随着膜后PO2升高，左心室PO2仍保持较低水平；这些值无显著相关性（r = 0.234，p = 0.61）。在右心房至脐静脉的ECMO期间，左心室和膜后PO2呈现显著正相关（r = 0.855，p = 0.014）。当ECMO途径从右心房至颈动脉改为右心房至脐静脉时，左心室PO2显著升高，左心室PCO2降低，而循环中其他部位的呼吸气体和pH值保持不变。在心肌不同部位的所有四个样本中，右心房至脐静脉的ECMO期间微球计数始终高于右心房至颈动脉的ECMO期间（配对t检验，p < 0.001）。
右心房至脐静脉的ECMO比右心房至颈动脉的ECMO能提供更有效的心脏氧合。
