Roemer V M
Frauenklinik der Klinikum Lippe Detmold GmbH, Lehrkrankenhaus der Westfälischen Wihelms-Universität Münster, Detmold.
Z Geburtshilfe Neonatol. 2003 Jul-Aug;207(4):121-6. doi: 10.1055/s-2003-42803.
As a role, the severity of "CTG pathology" in acute or chronic fetal hypoxia could only be registered but not quantified exactly by visual examination. For this reason, the term "CTG pathology" has not been unequivocally defined. The objective of the present study was to describe the dependence of fetal heart rate phenomena on the parameters of the acid-base balance quantitatively and to subject the latter to statistical analysis.
The last 120 minutes of a total of 411 interference-free cardiotocograms directly registered intra partum (HP, 2 cm/min) were evaluated in terms of the visual appearance of CTG: the frequency level and the fluctuation of every single minute and the deceleration-area sum were considered for 30 CTG minutes per fetus. A new CTG score was conceived which envisages six points for the mean frequency according to specific definitions, three points for the deceleration-area and further six points for the fluctuation (long-term variability). The heart rate data and clinical factors were analyzed off-line using parametric and non-parametric test procedures with special programs (FORTRAN) on an IBM system (6150). Besides the pH values in the umbilical arterial and venous blood, direct measurements of blood gases (pO(2), pCO(2)) were also available in 113 cases, so that the base excess (mmol/l) and the oxygen saturation (%) could be calculated according to known algorithms.
For the last 30 minutes ante partum, the CTG score correlates highly significantly (P << 10(-4)) with the actual pH value in the umbilical arterial blood (r = -0.6002). The correlation with the base excess is better (r = 0.642, P << 10(-4)), whereas the correlation with the directly measured pCO (2) is weaker (r = 0.587). Such strict correlations could not be demonstrated for oxygen saturation in the umbilical arterial or umbilical venous blood (r = -0.258, P = 0.0057 and r = -0.308, P = 0.0009).
The good correlations of the variables of the fetal acid-base balance with the CTG phenomena registered with the score can be used for clinical purposes. However, analysis of the CTG with the naked eye is not practically feasible for the obstetricians; it must therefore be done per computer. Quantitative CTG analysis has created the perspective of a promising new method for fetal monitoring sub partu.
作为一种手段，急性或慢性胎儿缺氧时“CTG病理”的严重程度只能通过视觉检查记录下来，但无法精确量化。因此，“CTG病理”这一术语尚未得到明确界定。本研究的目的是定量描述胎儿心率现象与酸碱平衡参数之间的相关性，并对后者进行统计分析。
对411份分娩时直接记录的无干扰宫缩图（HP，2 cm/min）的最后120分钟进行评估，评估依据CTG的视觉表现：考虑每个胎儿30分钟CTG的频率水平、每分钟的波动情况以及减速区总和。设计了一种新的CTG评分，根据特定定义，平均频率计6分，减速区计3分，波动（长期变异性）计6分。使用IBM系统（6150）上的特殊程序（FORTRAN），通过参数和非参数检验程序对心率数据和临床因素进行离线分析。除了脐动脉和脐静脉血中的pH值外，113例病例还可直接测量血气（pO₂、pCO₂），从而可根据已知算法计算碱剩余（mmol/l）和氧饱和度（%）。
分娩前最后30分钟，CTG评分与脐动脉血实际pH值高度显著相关（P << 10⁻⁴）（r = -0.6002）。与碱剩余的相关性更好（r = 0.642，P << 10⁻⁴），而与直接测量的pCO₂的相关性较弱（r = 0.587）。脐动脉血或脐静脉血氧饱和度未显示出如此严格的相关性（r = -0.258，P = 0.0057和r = -0.308，P = 0.0009）。
胎儿酸碱平衡变量与用该评分记录的CTG现象之间的良好相关性可用于临床。然而，产科医生用肉眼分析CTG在实际中不可行；因此必须通过计算机进行。定量CTG分析为分娩期胎儿监测创造了一种有前景的新方法。
