用于动物模型中因间歇性脐带受压导致急性胎儿缺氧的产前诊断的Tei指数。

Guorong Lv, Shaozheng He, Zhenghua Wang, Boyi Li, Qiuyue Chen, Peng Jin, Ruiyuan Su

Department of Ultrasound, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian, China.

Prenat Diagn. 2007 Sep;27(9):817-23. doi: 10.1002/pd.1781.

OBJECTIVE

To study the effectiveness of the pulsatility index for veins of ductus venosus (DV-PIV) and the Tei index in a prospective assessment of fetal hypoxic-ischemic brain damage in a near-term ovine fetus model with intermittent umbilical cord occlusion (UCO).

METHODS

Twelve fetal sheep were studied with umbilical cord occlusion performed in the experimental group animals by complete inflation of an occluder cuff for 90 s, every 30 min for approximately 2.5 h. Fetal arterial blood was sampled at 5 min before the first umbilical cord occlusions, approximately 60 s of the first umbilical cord occlusions, and 3 min after each occlusion for blood gas, pH, neuron-specific enolase (NSE) and S100B. Doppler measurements and Doppler echocardiographic examinations were performed 5 min before the first umbilical cord occlusions and 3 min after each successive occlusion.

RESULTS

In experimental group animals, UCO caused a large decline in arterial PaO(2) (to approximately 7.70 mmHg, p < 0.01), a modest decline in pH (to approximately 7.24, p < 0.01), and a modest rise in PaCO(2) (to approximately 53.31 mmHg, p < 0.01), with a return more or less to baseline after occluder release. and there was significant change as compared with the control animals (all p < 0.01) with cumulative changes in responses to repetitive cord occlusions. The DV-PIV waveforms, right ventricle (RV) and LV Tei indices, the serum levels of NSE and S100B increased with cord occlusions (all p < 0.05), and were significantly higher than the control animals (all p < 0.05) with a cumulative changes in responses to repetitive cord occlusions. RV and LV Tei indices were significantly correlated with PaO(2) (r = - 0.684, p < 0.01 and r = - 0.725, p < 0.01), PaCO(2) (r = 0.682, p < 0.01 and r = 0.780, p < 0.01), pH (r = - 0.538, p < 0.01 and r = - 0.681, p < 0.01), NSE (r = 0.653, p < 0.01 and r = 0.687, p < 0.01), and S100B (r = 0.606, p < 0.01 and r = 0.640, p < 0.01). Significant but weaker correlations were also present between DV-PIV and the parameters considered.

CONCLUSION

Umbilical cord occlusion during the latter part of the pregnancy, enough to cause significant hypoxemia and acidosis, results in a significant increase of DV-PIV, RV and LV Tei indices, and the serum levels of NSE and S100B. There was a strong correlation between the RV and LV Tei indices and blood gas, pH, and NSE, S100B with hypoxia. Therefore, the Tei index might be an easy and useful quantitative parameter for assessing fetal hypoxic ischemia.

目的

在近足月绵羊胎儿间歇性脐带阻塞（UCO）模型中，前瞻性研究静脉导管搏动指数（DV - PIV）和Tei指数对胎儿缺氧缺血性脑损伤评估的有效性。

方法

对12只胎羊进行研究，实验组动物通过完全充盈阻塞袖带90秒来进行脐带阻塞，每30分钟进行一次，持续约2.5小时。在首次脐带阻塞前5分钟、首次脐带阻塞约60秒时以及每次阻塞后3分钟采集胎儿动脉血，检测血气、pH值、神经元特异性烯醇化酶（NSE）和S100B。在首次脐带阻塞前5分钟和每次连续阻塞后3分钟进行多普勒测量和多普勒超声心动图检查。

结果

在实验组动物中，脐带阻塞导致动脉血氧分压（PaO₂）大幅下降（至约7.70 mmHg，p < 0.01），pH值适度下降（至约7.24，p < 0.01），二氧化碳分压（PaCO₂）适度升高（至约53.31 mmHg，p < 0.01），阻塞解除后或多或少恢复至基线水平。与对照组动物相比有显著变化（所有p < 0.01），对重复脐带阻塞的反应有累积变化。随着脐带阻塞，DV - PIV波形、右心室（RV）和左心室（LV）Tei指数、NSE和S100B血清水平升高（所有p < 0.05），且对重复脐带阻塞的反应有累积变化，显著高于对照组动物（所有p < 0.05）。RV和LV Tei指数与PaO₂（r = - 0.684，p < 0.01和r = - 0.725，p < 0.01）、PaCO₂（r = 0.682，p < 0.01和r = 0.780，p < 0.01）、pH（r = - 0.538，p < 0.01和r = - 0.681，p < 0.01）、NSE（r = 0.653，p < 0.01和r = 0.687，p < 0.01）以及S100B（r = 0.606，p < 0.01和r = 0.640，p < 0.01）显著相关。DV - PIV与所考虑的参数之间也存在显著但较弱的相关性。