胎儿羊急性母体缺氧时的心输出量和血流容积再分布。

Cardiac output and blood flow volume redistribution during acute maternal hypoxia in fetal sheep.

机构信息

Department of Obstetrics and Gynecology, University Medical Center Mainz, Germany.

出版信息

J Perinat Med. 2010 Jul;38(4):387-92. doi: 10.1515/jpm.2010.053.

DOI:10.1515/jpm.2010.053

PMID:20236035

Abstract

OBJECTIVE

Acute hypoxia is one of the main causes of poor neonatal outcome. The aim of this study was the investigation of cardiac output (CO) and blood flow redistribution following induction of acute hypoxia in a fetal sheep model.

METHOD

We investigated 10 fetal sheep between 108 and 130 days of gestation. Acute hypoxia was induced by reducing the O(2) saturation in the ventilated gas mixture of the maternal sheep to approximately 75%. The CO, placental fraction of CO, Doppler parameters in the ductus venosus (DV), umbilical artery (UA) and vein (UV) were measured.

RESULTS

The fetal pO(2) decreased from 47.1 (7.19; 7.35) to 6.89 (6.78; 7.11) mm Hg [P=0.01, median, (95% CI)] during hypoxia. Fetal pH and BE were also significantly reduced. The DV/UV fraction increased from 15.3 (11.5; 19.8) to 51.1 (35.9; 62.1) (P=0.0001). The combined cardiac output [1228.1 (1024.3; 1686.4) vs. 987.8 (834, 1261) mL min(-1)], the placental fraction of the CO [31.5 (26; 42.1) vs. 26.9 (20.6; 29.3)%] and the right to left (R/L) heart ratio [1.76 (1.5; 2.2) vs. 1.3 (1.1; 1.6)] significantly decreased during hypoxia.

CONCLUSIONS

Acute hypoxia significantly increases the proportion of the placental blood passing through the DV and reduces the placental fraction of CO and the R/L heart ratio. These findings could be used as early signs of acute fetal hypoxia.

摘要

目的

急性缺氧是导致新生儿预后不良的主要原因之一。本研究旨在探讨在胎儿羊模型中诱导急性缺氧后心输出量（CO）和血流重新分布的情况。

方法

我们研究了 10 只妊娠 108 至 130 天的胎儿羊。通过将母羊通气气体混合物中的氧饱和度降低至约 75%来诱导急性缺氧。测量 CO、胎盘 CO 分数、静脉导管（DV）、脐动脉（UA）和静脉（UV）的多普勒参数。

结果

胎儿 pO2 从 47.1（7.19；7.35）降至 6.89（6.78；7.11）mmHg [P=0.01，中位数，（95%CI）]，胎儿 pH 和 BE 也显著降低。DV/UV 分数从 15.3（11.5；19.8）增加至 51.1（35.9；62.1）（P=0.0001）。心输出量总和[1228.1（1024.3；1686.4）与 987.8（834，1261）mL min(-1)]、胎盘 CO 分数[31.5（26；42.1）与 26.9（20.6；29.3）%]和右心至左心（R/L）比值[1.76（1.5；2.2）与 1.3（1.1；1.6）]在缺氧期间显著降低。