Year: 1982
Type: article
Abstract: This report deals with first clinical experiences with continuous measurements of tcPco 2 in the human fetus.This technique has only now come into fruition after a long interval between the first report which was made by our Research Group in 1973 (1) about the basic possibility to measure this parameter and the present day.A total of 8 fetuses have been studied during delivery, in the Department of Obstetrics, University of Zürich.A laboratory designed, or the Dräger prototype tcPco 2 electrode was used for fetal scalp tcPco2 measurements.These two electrodes are similar in design and construction.Multichannel monitoring equipment was used to make simultaneous recordings of fetal and maternal tcPco 2 , maternal Po 2 , uterine activi.tyand fetal heart rate.The electrode was sterilized in ethylene oxide (Anprolene R) before calibration in 5% and 10% Co 2 .The application of the tcPco 2 electrode was performed using the same technique äs used for fetal tcPo 2 (2).First observations were related to the level and fluctuations of fetal transcutaneous Pco 2 .The uncorrected levels of tcPco 2 for all fetuses studied ranged between 42 -67 mm Hg with a mean of 52 mm Hg.There was a tendency for a slight increase towards the end of the first stage of labour in 5 cases.In one of the recordings during the second stage of labour, a fetal bradycardia of 12 min duration was observed, which was accompanied with an increase of fetal tcPco 2 from 52 to 85 mm Hg.Two types of fetal carbon dioxide fluctuations were noted in relation to uterine contractions.Small decreases of fetal tcPco 2 started about 1o seconds after the beginning of each contraction and returned to the previous level once the contraction was over.These small decreases in fetal tcPco 2 were apparently not related in time nor in amplitude to maternal tcPco 2 fluctuations äs was deduced from simultaneous maternal tcPco 2 recordings.In contrast, in some of the recordings, fetal scalp tcPo 2 was seen to increase slightly during contractions.Further studies will show whether the described fluctuations are related to changes in temperature , local perfusion beneath the electrode or physiological changes in the perfusion of the fetal scalp.First insights into maternal-fetal carbon dioxide relationships have become possible by "simultaneous maternal and fetal Pco 2 recordings.It was especially interesting to observe the effect of pethidine given to the mother on maternal respiration and on maternal and fetal tcPco 2 .As a result of reduced maternal hyperventilation after pain relief and/or central sedation maternal tcPco 2 usually increased after pethidine administration.Similar effects on fetal tcPco 2 within 40 min of administration of the analgesic were observed.Fig. l shows that the increase in maternal carbon 03005577
Source: Journal of Perinatal Medicine
Authors: R. Huch, A. Lysikiewicz, K. Vetter, A. Huch
Language: English
Subfield: Analytical Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1964565089