Glue fixation of the tcPco2 electrode for fetal monitoring

tcPco2 monitoring on the fetal scalp potentially is a beneficial and additional new tool for the surveillance of the unborn child. During a clinical trial we investigated the tcPco2 monitoring using the glue fixation technique. A modified Severingshaus electrode was applied on a prepared area on the fetal scalp by means of an endoscope. The attempt of application was successful in 224 out of 245 cases, while reapplication was only necessary in 8 cases. The accuracy of the tcPco2 measurement using glue fixation was sufficient at both measuring temperatures (39 degrees C and 44 degrees C). The correlation coefficient comparing the data with the tcPco2 of the fetal blood was 0.74 respectively 0.81. The development of a caput succedaneum leads to higher absolute values of the tcPco2. When a caput succedaneum has developed in the measuring area the mean value of the tcPco2 is significantly higher (62.70 mmHg instead of 55.14 mmHg respectively 68.98 mmHg instead of 65.98 mmHg) at 39 degrees C respectively 44 degrees C. No significant influence of different preparation techniques of the measuring site has been found during this investigation. The glue fixation technique leads to a reliable recording of tcPco2 in the fetus during labor, when the electrode is placed in a central and not compressed position on the lower pole of the fetus. The disadvantage is the necessity of extensive training of the personnel and the large number of instruments, factors that will interfere with a more widespread use in clinical routine.