Piercy W N, Day M A, Neims A H, Williams R L
Am J Obstet Gynecol. 1977 Jan 1;127(1):43-9. doi: 10.1016/0002-9378(77)90312-x.
The effects of diazepam, caffeine citrate, and doxapram on fetal respiratory-like activity (RLA) were studied in 10 chronic sheep preparations (90 to 130 days' gestation). We define fetal RLA as regular changes in fetal tracheal pressure occurring with a frequency of at least 1 Hz and an amplitude greater than -5 mm. Hg in the absence of fluctuations in amniotic cavity pressure. In all maternal (8) and fetal (7) intravenous infusions of diazepam (5 to 10 mg.), RLA ceased almost instantaneously. The duration of fetal apnea varied from 29 to 70 minutes with a mean of 57 minutes, and on occasion, a gasping pattern preceded recovery of RLA. Maternal and fetal plasma concentrations of diazepam indicated rapid bidirectional placental transfer. Intravenous infusion of doxapram (3 mg.) to the fetus immediately initiated a transient episode of RLA in 19 of 20 trials. Fetal infusion of caffeine citrate (10 to 20 mg.), especially via the carotid artery, was also associated with the rapid onset of a transient episode of fetal breathing. Saline control infusions were without effect. Fetal blood gases and pH were not altered by the administration of diazepam, caffeine citrate, or doxapram. It is suggested that each drug owes its action on RLA to an effect on fetal central nervous system. The influence of pharmacologic agents on the process and interpretation of fetal monitoring requires continued attention.
在10只妊娠90至130天的慢性绵羊实验准备中，研究了地西泮、枸橼酸咖啡因和多沙普仑对胎儿呼吸样活动（RLA）的影响。我们将胎儿RLA定义为胎儿气管压力的规律性变化，其频率至少为1赫兹，幅度大于-5毫米汞柱，且羊膜腔内压力无波动。在所有母体（8只）和胎儿（7只）静脉注射地西泮（5至10毫克）时，RLA几乎立即停止。胎儿呼吸暂停的持续时间从29分钟到70分钟不等，平均为57分钟，有时在RLA恢复之前会出现喘息模式。母体和胎儿血浆中的地西泮浓度表明胎盘存在快速双向转运。向胎儿静脉注射多沙普仑（3毫克），在20次试验中有19次立即引发了短暂的RLA发作。向胎儿输注枸橼酸咖啡因（10至20毫克），尤其是通过颈动脉输注，也与胎儿呼吸短暂发作的快速开始有关。生理盐水对照输注无效果。地西泮、枸橼酸咖啡因或多沙普仑的给药未改变胎儿血气和pH值。提示每种药物对RLA的作用归因于对胎儿中枢神经系统的影响。药理制剂对胎儿监测过程和解读的影响需要持续关注。
