McNamara H, Johnson N, Lilford R
Leeds University, U.K.
Br J Obstet Gynaecol. 1993 May;100(5):446-9. doi: 10.1111/j.1471-0528.1993.tb15269.x.
To determine if pulse oximetry could detect any changes in fetal arteriolar oxygen saturation resulting from maternal administration of oxygen.
A prospective study comparing study comparing the fetal pulse oximetry reading before and after giving 27% and 100% oxygen to the mother. The data were collected using an experimental pulse oximeter and a sensor specifically adapted to cope with the problems of fetal pulse oximetry.
Labour ward, St. Jame's University Hospital, Leeds University, UK.
Twelve fetuses presenting by the vertex in normal uncomplicated labour.
The change in fetal arteriolar oxygen saturation recorded by the pulse oximeter in response to oxygen administration to the mother.
Twenty-seven percent oxygen increased the average fetal arteriolar oxygen saturation by 7.5%, the effect being reversed when the oxygen was withdrawn. One hundred percent oxygen increased fetal arteriolar oxygen saturation by 11% and when the oxygen was withdrawn oxygen saturation dropped by 10%. One hundred percent inspired maternal oxygen was more effective than 27%. The gradient of the fetal oxygen regression slope is steeper with 100% oxygen than 27% and it is steeper when oxygen is given compared to when it is withdrawn. This suggests that the fetus responds to the new placental oxygen gradient by accepting oxygen more rapidly than it gives it up. Using a quadratic regression model, it took 9 min for fetal oxygen saturation to reach its maximum value after giving the mother oxygen.
This study confirms that a pulse oximeter is able to measure an increase in fetal arteriolar oxygen saturation when oxygen is administered to the mother.
确定脉搏血氧饱和度测定法能否检测到母亲吸氧后胎儿小动脉血氧饱和度的任何变化。
一项前瞻性研究，比较母亲吸入27%和100%氧气前后胎儿脉搏血氧饱和度的读数。使用实验性脉搏血氧仪和专门为应对胎儿脉搏血氧饱和度测定问题而设计的传感器收集数据。
英国利兹大学圣詹姆斯大学医院产房。
12例头先露、正常无并发症分娩的胎儿。
脉搏血氧仪记录的母亲吸氧后胎儿小动脉血氧饱和度的变化。
27%的氧气使胎儿小动脉平均血氧饱和度增加7.5%，停止吸氧后效果逆转。100%的氧气使胎儿小动脉血氧饱和度增加11%，停止吸氧后血氧饱和度下降10%。母亲吸入100%的氧气比吸入27%的氧气更有效。100%氧气时胎儿氧回归斜率的梯度比27%时更陡，且吸氧时比停止吸氧时更陡。这表明胎儿对新的胎盘氧梯度的反应是接受氧气的速度比释放氧气的速度更快。使用二次回归模型，给母亲吸氧后胎儿血氧饱和度达到最大值需要9分钟。
本研究证实，当给母亲吸氧时，脉搏血氧仪能够测量胎儿小动脉血氧饱和度的增加。
