不同脂肪乳剂预先给药对罗哌卡因致老龄大鼠心血管毒性的影响

目的 评价不同脂肪乳剂预先给药对罗哌卡因致老龄大鼠心血管毒性的影响.方法 健康雄性SD大鼠24只,月龄18月,体重400～550 g,随机分为3组(n=8):生理盐水组(NS组)、长链脂肪乳剂组(LLE组)和中/长链脂肪乳剂组(MLE组).腹腔注射氯胺酮100 mg/ks麻醉,监测ECG、BP和HR,气管插管后行机械通气,潮气量2 ml/100 g,通气频率60次/min.静脉注射维库溴铵0.5 mg维持肌松.NS组、LLE组和MLE组分别经颈静脉输注0.9%氯化钠注射液、20%长链脂肪乳剂注射液和20%中/长链脂肪乳剂注射液,输注速率均为3 ml·ks~(-1)·min~(-1);5 min后均静脉输注0.75%盐酸罗哌卡因注射液10 mg·ks~(-1)·min~(-1),直至出现心跳停止.记录出现心律失常时、BP较基础值下降20%时和心跳停止时罗哌卡因的用量.结果 与NS组比较,LLE组和MLE组出现心律失常时、血压较基础值下降20%时和心跳停止时罗哌卡因的用量增加(P＜0.05);LLE组和MLE组出现心律失常时、BP较基础值下降20%时和心跳停止时罗哌卡因的用量比较差异无统计学意义(P＞0.05).结论 长链脂肪乳剂和中/长链脂肪乳剂预先给药可减轻罗哌卡因致老龄大鼠心血管毒性.

Effects of different lipid emulsion pretreatment on ropivacaine cardiotoxicity in aged rats

Objective To investigate the effects of different lipid emulsions(LE)on ropivacaine cardiotoxicity in aged rats.Methods Twenty-four healthy male SD rats aged 18 months weighing 400-550 g were randomized into 3 groups(n = 8 each): group Ⅰ control(group C); group Ⅱ long chain lipid emulsion(group LLE)and group Ⅲ medium and long chain lipid emulsion(group MLE).The rats were anesthetized with intraperitoneal(IP)ketamine 100 mg/kg.The right jugular vein and carotid artery were cannulated for drug administration and BP monitoring.The trachea was intubated with a 16 G cannula which was connected to a small animal ventilator.20% LLE or 20% MLE was infused at 3 ml·kg~(-1)·min~(-1) for 5 min in group Ⅱ and Ⅲrespectively.0.75 % ropivacaine was then infused iv at 10 ml·kg~(-1)·min~(-1) through right jugular vein.The amount of ropivacaine infused when cardiac dysrhythmia or BP decreased by 20% or cardiac arrest occurred was recorded.Results The amount of ropivacaine infused when cardiotoxicity occurred was significantly larger in group LLE and MLE than in control group but was not significantly different between group LLE and MLE.Conclusion Pretreatment with LLE or MLE has protective effect against ropivacaine cardiotoxicity in aged rats.