Stereoselectivity in the placental transfer and kinetic disposition of racemic bupivacaine administered to parturients with or without a vasoconstrictor

The aim of the present study was to investigate the stereoselectivity in the kinetic disposition and the transplacental distribution of bupivacaine in term parturients during labor. Maternal age ranged from 18-37 years and fetal gestational age from 37.6-41.5 weeks. Healthy parturients (n = 23) received epidural 0.5% racemic bupivacaine alone (group A) or combined with epinephrine (group B). Maternal venous blood was sampled at regular intervals until 8 h after drug administration and umbilical venous blood was obtained at delivery. Bupivacaine enantiomers were determined in plasma samples by HPLC using a Chiralcel(R) OD-R column and a UV detector. One- or two-compartment models were fitted to data and differences between the (+)-(R) and (-)-(S) enantiomers were compared with the paired Wilcoxon test (P< 0.05). The influence of epinephrine was evaluated using the unpaired Mann-Whitney test (P< 0.05). The disposition of bupivacaine in maternal plasma was stereoselective, with higher V(d/f) (140.60 vs. 132.81 L for group A and 197.86 vs. 169.46 L for group B) and C(l/f) (29.00 vs. 25.43 L/h for group A and 33.15 vs. 26.39 L/h for group B) and lower t(1/2)beta (3.24 vs. 3.30 h for group A and 4.36 vs. 4.45 h for group B) being observed for (+)-(R)-bupivacaine. The combined administration of epinephrine resulted in higher V(d/f) (197.86 vs. 140.60 L for (+)-(R) and 169.46 vs. 132.81 L for (-)-(S)) and t(1/2)beta values (4.36 vs. 3.24 h for (+)-(R) and 4.45 vs. 3.30 h for (-)-(S)). The transplacental distribution of bupivacaine was stereoselective only when bupivacaine was administered without epinephrine (group B), with a higher cord blood/maternal blood ratio being observed for (-)-(S)-bupivacaine (0.40 vs. 0.35). Chirality 16:65-71, 2004.     

二胎产妇住院期间纯母乳喂养现状调查及影响因素的Logistic回归分析

摘要 目的：调查二胎产妇住院期间纯母乳喂养现状,并以单因素及多因素Logistic回归分析纯母乳喂养的影响因素。方法：选取2020年5~10月期间在西北妇女儿童医院妇产科住院分娩的600例二胎产妇,自行设计问卷调查其喂养方式和母乳喂养知识掌握情况,采用中文版母乳喂养态度量表评估产妇的母乳喂养态度。根据实际喂养方式将600例二胎产妇分为纯母乳喂养组和非纯母乳喂养组,以单因素及多因素Logistic回归分析纯母乳喂养的影响因素。结果：600例二胎产妇中,纯母乳喂养组470例,非纯母乳喂养组130例,纯母乳喂养占比为78.33%;423例二胎产妇母乳喂养知识评分＞20分,母乳喂养知识掌握率为70.50%;253例为积极母乳喂养态度,积极母乳喂养态度的二胎产妇占比42.17%。单因素分析结果显示,纯母乳喂养组新生儿每天吸吮次数＞8次、一胎主要为纯母乳喂养、大专及以上文化程度、家庭平均月收入＞6000元、掌握母乳喂养知识、积极母乳喂养态度的产妇比例高于非纯母乳喂养组（P<0.05）,而剖宫产、乳头凹陷、乳汁分泌不足的产妇比例低于非纯母乳喂养组（P<0.05）。多因素Logistic回归分析结果显示,剖宫产、乳头凹陷、乳汁分泌不足、新生儿每天吸吮次数≤8次、一胎主要为非纯母乳喂养、中专（高中）及以下文化程度、家庭平均月收入≤6000元、未掌握母乳喂养知识、非积极母乳喂养态度均是二胎产妇住院期间纯母乳喂养的不利影响因素（P<0.05）。结论：二胎产妇住院期间纯母乳喂养现状处于中等偏上水平,其影响因素包括分娩方式、乳头凹陷、乳汁分泌情况等,临床应结合相关影响因素针对性干预以提高产妇纯母乳喂养率。