Objective To investigate the effects of three different doses propofol pretreatment on the central nervous system and cardiac toxicities of bupivacaine. Methods Forty male SD rats were randomly assigned to four groups (n = 10 each). A Ⅱ -lead electrocardiogram (ECG) was continuously monitored. The femoral artery was cannulated for direct measurement of arterial blood pressure and the femoral vein was cannulated for infusion of drugs. Control group (group C) received infusion of saline 10 mL /kg while other three groups received infusion of propofol 25 mg/kg (group PⅠ), 50 mg/kg (group PⅡ) and 100 mg/kg (group PⅢ) respectively. All infusions were completed within 5 min. After 15 min, all rats received infusion of 0.5％ bupivacaine at the rate of (2 mg/kg-1·min-1) until asystole occurred. The times for bupivacaine-induced convulsions, arrhythmia (QRS prolongation in ECG) and asystole were determined. The infused doses of bupivacaine were calculated at the corresponding time point respectively. Results The doses of bupivacaine that induced convulsions, arrhythmia and asystole in groups P Ⅰ,P Ⅱ and PⅢ were larger than that of group C respectively, and the doses of bupivacaine in groups P Ⅱ and PⅢ were larger than that of group PⅠ (P ＜ 0.05), but there was no significant difference between group P Ⅱ and PⅢ (P＞ 0.05).Conclusions Propofol pretreatment can prevent the central nervous system and cardiac toxicities of bupivacaine in rats, and it produces a dose-dependent protectire effect within a certain dose range.%目的:探讨预先给予三种不同剂量丙泊酚时布比卡因中枢和心脏毒性反应的影响.方法:4|D只雄性SD大鼠随机分为4组.每组10只,以肢体Ⅱ导联监测ECG,股动脉置入24G套管针监测BP,股静脉置入24G套管针.泵注布比卡因开始前15 min,对照组静脉泵注生理盐水(C组),另外3组分别泵注丙泊酚25 mg/kg(PI组)、50 mg/kg(PⅡ组)和100 mg/kg(Pa组),4组注射容积为10 mL/kg,均在5 min内泵注完,然后所有动物泵注0.5%布比卡因2 mg/(kg·rain).记录大鼠发生抽搐、心律失常和心跳停止的时间及布比卡因用量.结果:大鼠出现抽搐、心律失常和心跳停止时,PI组、PⅡ组和Pa组的局麻药用量大于C组,PⅡ组和PⅢ组的用量也大于PIflt.(P<0.05),但PⅡ组和PⅢ组间差异无显著统计学意义(P>0.05).结论:丙泊酚预先给药可明显减轻布比卡因的中枢和心脏毒性反应,且在一定剂量范围内呈剂量依赖性.
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