Laishley R S, Carson R J, Reynolds F
Anaesthetic Unit, St Thomas' Hospital, London.
Br J Anaesth. 1989 Oct;63(4):439-43. doi: 10.1093/bja/63.4.439.
Following general anaesthesia, each of 18 pregnant rabbits received an i.v. infusion, at a declining rate, of 0.125% bupivacaine, either plain solution followed by adrenaline (1.25 micrograms ml-1)-containing solution (n = 10) or vice versa (n = 8). All solutions contained antipyrine as an index of placental exchange. In each rabbit, a single fetal sac was opened, the umbilical vessels were cannulated and the placenta was perfused in situ with buffered Krebs solution containing Dextran. Bupivacaine and antipyrine concentrations were measured in effluent perfusate (fetal) and in maternal plasma sampled simultaneously. Mean maternal arterial pressure and mean placental perfusion pressure were not altered by adrenaline. Fetal:maternal concentration (F:M) ratios of antipyrine decreased significantly (P less than 0.05) during the second half of the experiment. In contrast, F:M ratios of bupivacaine were unchanged during the time course of the experiment and unaltered by the addition of adrenaline. It is concluded that neither adrenaline nor minor alterations in maternal placental flow affect placental transfer of bupivacaine.
全身麻醉后，18只孕兔每只均静脉输注0.125%布比卡因，输注速率递减，其中10只先输注普通溶液，后输注含肾上腺素（1.25微克/毫升）的溶液，另外8只则先输注含肾上腺素的溶液，后输注普通溶液。所有溶液均含有安替比林作为胎盘交换的指标。在每只兔子身上，打开一个胎儿囊，将脐血管插管，并用含右旋糖酐的缓冲 Krebs 溶液对胎盘进行原位灌注。同时测量流出灌注液（胎儿）和母体血浆中的布比卡因和安替比林浓度。肾上腺素未改变母体平均动脉压和平均胎盘灌注压。在实验后半段，安替比林的胎儿：母体浓度（F:M）比值显著降低（P<0.05）。相比之下，布比卡因的F:M比值在实验过程中未发生变化，且不受肾上腺素添加的影响。结论是，肾上腺素和母体胎盘血流的微小变化均不影响布比卡因的胎盘转运。
