Sykes G S, Molloy P M, Wollner J C, Burton P J, Wolton B, Rolfe P, Johnson P, Turnbull A C
Am J Obstet Gynecol. 1984 Dec 1;150(7):847-58. doi: 10.1016/0002-9378(84)90461-7.
Clinical evaluation of the continuous, simultaneous measurement of fetal scalp surface oxygen and carbon dioxide partial pressures by mass spectrometry was undertaken for 52 labors. The mass spectrometer (MM8-80, V.G. Gas Analysis, Winsford, England) was easy to operate and had good long-term stability. The mean drifts for both oxygen and carbon dioxide over the study periods were less than 2 mm Hg. The mean (+/- SD) cervical dilatation at the time of transducer application was 6.1 (+/- 1.9) cm and the mean (+/- SD) duration of the studies was 169 (+/- 122) minutes; 10.5% of the transducer applications were unsuccessful. Falls in fetal scalp surface oxygen levels and rises in carbon dioxide levels were more frequent with late than with variable and with variable than with early fetal heart rate decelerations and with increasing severity and frequency of decelerations. Fetal scalp surface pressure changes also occurred with fetal heart rate variability changes, including some related to behavioral state changes. There was not a constant reciprocal relationship between oxygen and carbon dioxide changes, and fetal heart rate patterns were not related to actual blood gas levels. Fetal scalp surface measurements were related to both fetal blood sample and umbilical artery results. Trends in both oxygen and carbon dioxide levels during the course of labor were compared and related to other fetal variables, and most of the time the scalp surface measurements were an accurate guide to systemic blood gas levels. Maternal oxygen administration resulted in significant increase in fetal scalp surface oxygen levels, and on two of eight occasions it also led to decreases in fetal carbon dioxide levels. Scalp surface gas measurement by means of mass spectrometry is a powerful new method of intrapartum fetal monitoring, which should increase the precision of fetal surveillance as well as allow the accurate assessment of both established and new methods for optimizing labor and delivery.
采用质谱法对52例分娩过程中胎儿头皮表面氧分压和二氧化碳分压进行连续同步测量的临床评估。质谱仪（MM8 - 80，V.G.气体分析公司，英国温斯福德）操作简便，具有良好的长期稳定性。研究期间氧和二氧化碳的平均漂移均小于2 mmHg。应用传感器时宫颈扩张的平均（±标准差）值为6.1（±1.9）cm，研究的平均（±标准差）持续时间为169（±122）分钟；10.5%的传感器应用未成功。与变异减速和早期减速相比，晚期减速时胎儿头皮表面氧水平下降和二氧化碳水平上升更为频繁，且随着减速严重程度和频率的增加而更频繁。胎儿心率变异性改变时也会出现胎儿头皮表面压力变化，包括一些与行为状态改变有关的变化。氧和二氧化碳变化之间不存在恒定的反比关系，胎儿心率模式与实际血气水平无关。胎儿头皮表面测量结果与胎儿血样和脐动脉结果均相关。比较了分娩过程中氧和二氧化碳水平的变化趋势，并将其与其他胎儿变量相关联，大多数情况下，头皮表面测量是全身血气水平的准确指标。母体吸氧导致胎儿头皮表面氧水平显著升高，在8次中有2次还导致胎儿二氧化碳水平下降。通过质谱法进行头皮表面气体测量是一种强大的产时胎儿监测新方法，它应能提高胎儿监测的精度，并能准确评估优化分娩的现有方法和新方法。
