Ostman P L, Chestnut D H, Robillard J E, Weiner C P, Hdez M J
Department of Anesthesia, University of Chicago, Illinois 60637.
Anesthesiology. 1988 Nov;69(5):738-41. doi: 10.1097/00000542-198811000-00016.
Using a chronic maternal-fetal sheep preparation, the authors determined the transplacental passage and the hemodynamic changes consequent to maternal administration of esmolol. Fifteen experiments were performed in six chronically instrumented pregnant ewes near term. Each animal received esmolol iv, 500 micrograms.kg-1.min-1, for 4 min and then 300 micrograms.kg-1.min-1 for 6 min. Maternal and fetal blood esmolol concentrations (mean +/- SEM) were 1.2 +/- 0.28 and 0.1 +/- 0.03 micrograms/ml, respectively, at the completion of the infusion, and 0.03 +/- 0.01 microgram/ml in the mother and not detectable in the fetus 10 min after stopping the infusion. Despite the relatively low blood esmolol concentration in the fetus compared to the mother, the hemodynamic effects in the fetus were similar to those in the mother. The maximal decrease of maternal mean arterial pressure (MAP) and heart rate (HR) were 7 +/- 2 and 14 +/- 3% (mean +/- SEM), respectively (P less than .05). The maximal decrease of fetal MAP and HR were 7 +/- 2 and 12 +/- 3%, respectively (P less than .05). No changes were seen in maternal or fetal acid-base variables, and intra-amniotic pressure was not affected. The authors conclude that esmolol has a rapid but relatively small transplacental passage, and it is eliminated rapidly from both maternal and fetal plasma.
作者使用慢性母胎绵羊模型，确定了艾司洛尔经胎盘的转运情况以及母体给药后随之产生的血流动力学变化。对6只近足月的慢性植入仪器的怀孕母羊进行了15次实验。每只动物静脉注射艾司洛尔，剂量为500微克·千克⁻¹·分钟⁻¹，持续4分钟，然后以300微克·千克⁻¹·分钟⁻¹的剂量持续6分钟。输注结束时，母体和胎儿血液中艾司洛尔浓度（均值±标准误）分别为1.2±0.28微克/毫升和0.1±0.03微克/毫升，停止输注10分钟后，母体中为0.03±0.01微克/毫升，胎儿中未检测到。尽管与母体相比，胎儿血液中艾司洛尔浓度相对较低，但胎儿的血流动力学效应与母体相似。母体平均动脉压（MAP）和心率（HR）的最大降幅分别为7±2%和14±3%（均值±标准误）（P＜0.05）。胎儿MAP和HR的最大降幅分别为7±2%和12±3%（P＜0.05）。母体或胎儿的酸碱变量未见变化，羊膜腔内压力未受影响。作者得出结论，艾司洛尔经胎盘转运迅速但相对较少，且能迅速从母体和胎儿血浆中清除。
