Reynolds F, Laishley R, Morgan B, Lee A
Department of Anaesthetics, St Thomas' Hospital, London.
Br J Anaesth. 1989 May;62(5):509-14. doi: 10.1093/bja/62.5.509.
Following lumbar extradural analgesia with 0.5% bupivacaine, the placental transfer of bupivacaine was examined in 40 women undergoing elective and 40 women undergoing emergency Caesarean section. Within each group, the patients received randomly either plain bupivacaine or bupivacaine with adrenaline 1 in 200,000. Plasma bupivacaine concentrations were measured in blood samples taken simultaneously at delivery from the umbilical vein (UV), umbilical artery (UA) and maternal vein (MV). Bupivacaine concentrations in MV, UV and UA were not significantly affected by the presence of adrenaline, but were positively correlated with first dose to delivery interval (FDD) while MV and UV were inversely correlated with last dose to delivery interval (LDD). Mean ratio of UV:MV concentrations of bupivacaine was 0.346 and for UA:MV it was 0.305. There was no significant correlation between any fetal:maternal ratio and FDD or LDD. UA:UV ratio appeared to increase towards unity 30-40 min after the last dose. The presence of adrenaline was associated with an increase in UA:UV in the elective group (P less than 0.01). In eight patients who received adrenaline there was reverse placental transfer (UA:UV greater than 1). There was no evidence of progressive fetal accumulation of bupivacaine beyond 30-40 min.
在40例行择期剖宫产和40例行急诊剖宫产的妇女中，研究了0.5%布比卡因腰段硬膜外镇痛后布比卡因的胎盘转运情况。在每组中，患者随机接受普通布比卡因或含1:200,000肾上腺素的布比卡因。在分娩时同时采集脐静脉（UV）、脐动脉（UA）和母体静脉（MV）血样，测定血浆布比卡因浓度。MV、UV和UA中的布比卡因浓度不受肾上腺素的显著影响，但与首次给药至分娩间隔（FDD）呈正相关，而MV和UV与末次给药至分娩间隔（LDD）呈负相关。布比卡因UV:MV浓度的平均比值为0.346，UA:MV浓度的平均比值为0.305。任何胎儿与母体的比值与FDD或LDD之间均无显著相关性。末次给药后30 - 40分钟，UA:UV比值似乎趋向于1。在择期剖宫产组中，肾上腺素的存在与UA:UV升高有关（P小于0.01）。在8例接受肾上腺素的患者中出现了胎盘逆向转运（UA:UV大于1）。没有证据表明布比卡因在30 - 40分钟后会在胎儿体内进行性蓄积。
