Willis D M, Anderson D F, Thornburg K L, Faber J J
Biol Neonate. 1985;47(5):295-304. doi: 10.1159/000242131.
To study the effectiveness of in utero ventilation in altering fetal arterial gas composition, we ventilated 15 near-term fetal lambs with a range of inspired gas mixtures. To accomplish this, double lumen nasogastric tubes were surgically placed in the tracheas of 15 near-term (135 days' gestation) fetal lambs. After 4 +/- 1 SD postoperative days, the fetuses were respired by positive pressure ventilation. 13 of these fetuses were also ventilated with their umbilical cords completely occluded. Ventilation was maintained for an average of 4.5 h (range 2.5-7.5 h). All 15 fetuses were effectively oxygenated on room air when exposed to a small net positive end expiratory pressure. In fetuses with intact umbilical cords, PaO2 could be maintained at levels between 11 and 280 mm Hg and PaCO2 from 36 to 139 mm Hg by altering the inspired O2 and CO2 with a gas mixing device. During umbilical cord occlusion, PaO2 was regulated from 2.2 to 103 mm Hg and PaCO2 from 37 to 187 mm Hg.
为研究宫内通气改变胎儿动脉血气成分的有效性，我们用一系列吸入气体混合物对15只近足月胎羊进行通气。为此，通过手术将双腔鼻胃管置于15只近足月（妊娠135天）胎羊的气管内。术后4±1个标准差天数后，对胎儿进行正压通气。其中13只胎儿在完全阻断脐带的情况下也进行了通气。通气平均维持4.5小时（范围2.5 - 7.5小时）。当暴露于小的呼气末正压时，所有15只胎儿在室内空气中均得到有效氧合。在脐带完整的胎儿中，通过气体混合装置改变吸入的氧气和二氧化碳，可将动脉血氧分压（PaO2）维持在11至280毫米汞柱之间，动脉血二氧化碳分压（PaCO2）维持在36至139毫米汞柱之间。在脐带阻断期间，PaO2调节范围为2.2至103毫米汞柱，PaCO2调节范围为37至187毫米汞柱。
