Gleed R D, Poore E R, Figueroa J P, Nathanielsz P W
Am J Obstet Gynecol. 1986 Aug;155(2):429-35. doi: 10.1016/0002-9378(86)90846-x.
A new technique is described for producing changes in fetal blood gases in the chronically instrumented pregnant sheep. Gas mixtures were infused directly into the maternal trachea. Maternal and fetal carotid arterial blood gases and pH were measured. Air infusion at 16 L X min-1 produced no change. Oxygen infusion caused significant increases in maternal PaO2 at 2 L X min-1 and in fetal PaO2 at 4 L X min-1. Nitrogen infusion significantly decreased maternal anf fetal PaO2 at 4 L X min-1. During 4 L X min-1 oxygen infusion, maternal PaO2 rose rapidly to plateau at 314 +/- 47 mm Hg at 4 minutes and fetal PaO2 rose to plateau at 28.7 +/- 2.8 mm Hg after 7 to 8 minutes. Maternal PaO2 fell to 56.4 +/- 4.3 mm Hg during nitrogen infusion (4 L X min-1) while fetal PaO2 fell to 15.9 +/- 1.8 mm Hg. Continuous infusion for 5- to 6-hour periods produced a consistent rise in maternal PaO2 during oxygen infusion and a consistent decrease during nitrogen infusion. Tracheal infusion of gases can be used to change maternal and fetal PaO2 rapidly and predictably.
本文描述了一种用于在长期植入仪器的怀孕绵羊中改变胎儿血气的新技术。气体混合物直接注入母体气管。测量母体和胎儿颈动脉的血气及pH值。以16 L·min⁻¹的速率注入空气未产生变化。以2 L·min⁻¹的速率注入氧气会使母体PaO₂显著升高，以4 L·min⁻¹的速率注入会使胎儿PaO₂显著升高。以4 L·min⁻¹的速率注入氮气会使母体和胎儿的PaO₂显著降低。在以4 L·min⁻¹的速率注入氧气期间，母体PaO₂在4分钟时迅速上升至314±47 mmHg的平台期，胎儿PaO₂在7至8分钟后上升至28.7±2.8 mmHg的平台期。在注入氮气（4 L·min⁻¹）期间，母体PaO₂降至56.4±4.3 mmHg，而胎儿PaO₂降至15.9±1.8 mmHg。持续注入5至6小时会在注入氧气期间使母体PaO₂持续升高，在注入氮气期间持续降低。气管内注入气体可用于快速且可预测地改变母体和胎儿的PaO₂。
