PDF(Sci-hub)
Abstract：
BACKGROUND: The autonomic nervous system has a major role in fetal adaptation to hypoxia. Its activity might be assessed using heart rate variability and heart rate deceleration analyses.
OBJECTIVE: To evaluate the ability of different heart rate variability and morphological deceleration analyses to predict fetal acidosis during labor in an experimental fetal sheep model.
METHODS: Repeated 1-minute total umbilical cord occlusions were performed at mild (1minute every 5 min), moderate (1 min every 3 min), and severe (1 min every 2 min) umbilical cord occlusion periodicities until arterial pH reached 7.10. Hemodynamic,blood gas analysis, morphological analysis of decelerations (magnitude, slope, and area ofdecelerations), and heart rate variability parameters were recorded throughout the experiment.Heart rate variability analysis included temporal analysis (root mean square of successivedifferences between adjacent RR intervals, standard deviation of normal to normal RR intervals, short term variability), spectral analysis (low frequencies, high frequencies,normalized high frequencies), and a new index developed by our team, the Fetal Stress Index.We defined and compared three pH groups: >7.20, 7.10-7.20, and <7.10.
RESULTS: Eleven experiments were performed. Repetitive umbilical cord occlusions resulted in progressive fetal acidosis. Fetal Stress Index was correlated with pH and lactate (p < 0.05) and increased with acidosis. There were no significant correlations between pH, lactate, and other indices (spectral analysis, temporal analysis, or morphological analysis of decelerations).
CONCLUSIONS: This protocol allowed us to identify the progressive onset of fetal acidosis in an experimental model close to labor. Fetal Stress Index is a heart rate variability method that varies with acidosis and indicates an increase in parasympathetic nervous system activity in response to fetal acidosis.
OBJECTIVE: To evaluate the ability of different heart rate variability and morphological deceleration analyses to predict fetal acidosis during labor in an experimental fetal sheep model.
METHODS: Repeated 1-minute total umbilical cord occlusions were performed at mild (1minute every 5 min), moderate (1 min every 3 min), and severe (1 min every 2 min) umbilical cord occlusion periodicities until arterial pH reached 7.10. Hemodynamic,blood gas analysis, morphological analysis of decelerations (magnitude, slope, and area ofdecelerations), and heart rate variability parameters were recorded throughout the experiment.Heart rate variability analysis included temporal analysis (root mean square of successivedifferences between adjacent RR intervals, standard deviation of normal to normal RR intervals, short term variability), spectral analysis (low frequencies, high frequencies,normalized high frequencies), and a new index developed by our team, the Fetal Stress Index.We defined and compared three pH groups: >7.20, 7.10-7.20, and <7.10.
RESULTS: Eleven experiments were performed. Repetitive umbilical cord occlusions resulted in progressive fetal acidosis. Fetal Stress Index was correlated with pH and lactate (p < 0.05) and increased with acidosis. There were no significant correlations between pH, lactate, and other indices (spectral analysis, temporal analysis, or morphological analysis of decelerations).
CONCLUSIONS: This protocol allowed us to identify the progressive onset of fetal acidosis in an experimental model close to labor. Fetal Stress Index is a heart rate variability method that varies with acidosis and indicates an increase in parasympathetic nervous system activity in response to fetal acidosis.
摘要：
背景：自主神经系统在胎儿对缺氧的适应中起着重要作用。可以使用心率变异性和心率减速分析来评估其活动。
目的：评价不同心率变异性和形态学减速分析预测产程中胎儿酸中毒的能力。
方法：在轻度时（每5分钟1分钟）重复进行1分钟的完全脐带闭塞，中度（每3分钟1分钟），和严重（每2分钟1分钟）脐带闭塞周期，直到动脉pH值达到7.10。血流动力学,血气分析,减速的形态分析(幅度，斜坡,和减速区域)，在整个实验过程中记录心率变异性参数。心率变异性分析包括时间分析（相邻RR间期之间成功差异的均方根，正常到正常RR间期的标准偏差，短期变异性)，频谱分析(低频，高频,归一化高频)，和我们团队开发的新索引，胎儿压力指数。我们定义并比较了三个pH组：>7.20，7.10-7.20和<7.10。
结果：进行了11个实验。重复脐带闭塞导致进行性胎儿酸中毒。胎儿应激指数与pH和乳酸相关（p<0.05），并随酸中毒而增加。pH值,乳酸，和其他指标(光谱分析，时间分析,或减速的形态学分析)。
结论：该方案使我们能够在接近分娩的实验模型中确定胎儿酸中毒的进行性发作。胎儿应激指数是一种心率变异性方法，随酸中毒而变化，表明副交感神经系统活动因胎儿酸中毒而增加。
目的：评价不同心率变异性和形态学减速分析预测产程中胎儿酸中毒的能力。
方法：在轻度时（每5分钟1分钟）重复进行1分钟的完全脐带闭塞，中度（每3分钟1分钟），和严重（每2分钟1分钟）脐带闭塞周期，直到动脉pH值达到7.10。血流动力学,血气分析,减速的形态分析(幅度，斜坡,和减速区域)，在整个实验过程中记录心率变异性参数。心率变异性分析包括时间分析（相邻RR间期之间成功差异的均方根，正常到正常RR间期的标准偏差，短期变异性)，频谱分析(低频，高频,归一化高频)，和我们团队开发的新索引，胎儿压力指数。我们定义并比较了三个pH组：>7.20，7.10-7.20和<7.10。
结果：进行了11个实验。重复脐带闭塞导致进行性胎儿酸中毒。胎儿应激指数与pH和乳酸相关（p<0.05），并随酸中毒而增加。pH值,乳酸，和其他指标(光谱分析，时间分析,或减速的形态学分析)。
结论：该方案使我们能够在接近分娩的实验模型中确定胎儿酸中毒的进行性发作。胎儿应激指数是一种心率变异性方法，随酸中毒而变化，表明副交感神经系统活动因胎儿酸中毒而增加。
