Mueller-Heubach E, Caritis S N, Edelstone D I, Huch R, Huch A
Obstet Gynecol. 1981 Feb;57(2):248-52.
This study determined the validity of transcutaneous Po2 (tcPo2) versus Pao2 determinations in the sheep fetus. In 7 fetal lambs catheters were placed in the carotid artery and the trachea, and ECG leads and a tcPo2 electrode were attached. Intermittently determined Pao2 values were compared to continuously recorded tcPo2 values. Fetal tcPo2 values ranging from 12 to 29 mmHg were achieved by changing the gas mixture the ewe breathed or by inflation of a balloon catheter in the maternal aorta. Transcutaneous Po2 correlated strongly with Pao2 (r = .91). These studies indicate that the tcPo2 electrode precisely and accurately reflects Pao2 in the fetal lamb. Limitations of tcPo2 measurements regarding prolonged attachment of the electrode to the fetal skin as well as fetal skin tolerance to the heat of the electrode have been identified. With this electrode the changes in oxygen tension can be compared with changes in fetal cardiovascular variables, eg, heart rate, blood pressure, and ECG, for a better understanding of the effects of hypoxemia on the fetus.
本研究确定了经皮氧分压（tcPo2）测定相对于绵羊胎儿动脉血氧分压（Pao2）测定的有效性。对7只胎羊，将导管分别置于颈动脉和气管内，并连接心电图导联和tcPo2电极。将间歇性测定的Pao2值与连续记录的tcPo2值进行比较。通过改变母羊呼吸的气体混合物或在母羊主动脉内充气球囊导管，使胎儿tcPo2值达到12至29 mmHg。经皮氧分压与动脉血氧分压密切相关（r = 0.91）。这些研究表明，tcPo2电极能精确、准确地反映胎羊的动脉血氧分压。已确定了tcPo2测量在电极长时间附着于胎儿皮肤以及胎儿皮肤对电极热量的耐受性方面的局限性。使用该电极，可以将氧分压的变化与胎儿心血管变量（如心率、血压和心电图）的变化进行比较，以便更好地了解低氧血症对胎儿的影响。
