戊巴比妥钠和水合氯醛对窒息性心跳骤停大鼠心肺复苏后脑损伤的影响

目的 比较戊巴比妥钠和水合氯醛对窒息性心跳骤停大鼠心肺复苏后脑损伤的影响,为心肺复苏后脑保护的实验选择适宜的麻醉药物.方法 成年雄性SD大鼠160只,日龄70～95 d,体重300～400 g,随机分为2组(n=80):水合氯醛麻醉组(CH组)和戊己比妥钠麻醉组(P3组).各组再分为2个亚组(n=40):无心跳骤停对照组(CH-NR组或PB-NR组)和心跳骤停后心肺复苏组(CH-R组或PB-R组).CH组腹腔注射5%水合氯醛0.35 g/kg诱导麻醉,气管插管后行机械通气,每隔1 h腹腔注射5%水合氯醛0.1 g/kg维持麻醉;PB组腹腔注射0.35%戊巴比妥钠35 mg/kg诱导麻醉,气管插管后行机械通气,每隔1 h腹腔注射0.35%戊巴比妥钠10 mg/kg维持麻醉.CH-R组和PB-R组麻醉后建立窒息性心跳骤停后心肺复苏模型.于自主循环恢复后0.5、3、6、9、24 h(T1～5)时各处死8只大鼠,处死前15 min左侧股静脉注射2%伊文氏蓝(EB)2 ml/kg,处死后取脑组织测定脑组织含水量和EB含量.结果 与CH-NR组相比,CH-R组各时点脑组织含水量和EB含量增加(P<0.05);与PB-NR组相比,PB-R组各时点脑组织含水量和EB含量增加(P<0.05);与CH-R组相比,PB-R组T<2～5>时脑组织含水量降低(P<0.05),EB含量差异无统计学意义(P>0.05).结论 心跳骤停后心肺复苏可导致大鼠脑水肿和血脑屏障通透性增加.戊巴比妥钠较水合氯醛抑制脑水肿的程度大,而二者对血脑屏障通透性的影响无差异.

Influence of pentobarbital and chloral hydrate on cerebral injury after cardiopulmonary resuscitation in a rat model of cardiac arrest induced by asphyxia

Objective To investigate the influence of choral hydrate and pentobarbital on cerebral injury after cardiopulmonary resuscitation (CPR) in a rat model of cardiac arrest induced by asphyxia.Methods One hundred and sixty male 70-95 day old SD rats weighing 300-400 g were randomly divided into 2 anesthetic groups ( n = 80 each) : chloral hydrate group (CH) and pentobarbital group (PB).Each group was further divided into 2 subgroups ( n = 40 each) : control subgroup underwent no cardiac arrest and CPR subgroup.Anesthesia was induced with intraperitoneal (IP) 5% chloral hydrate 0.35 g/kg followed by intermittent IP 5% chloral hydrate 0.1 g/kg every hour in group CH and with IP 0.35% pentobarbital 35 mg/kg followed by intermittent IP 0.35% pentobarbital 10 mg/kg every hour in group PB.Left femoral vein and right carotid artery were cunnulated for drug and fluid administration and BP monitoring.The animals were tracheostomized and mechanically ventilated.Cardiac arrest was induced by occlusion of tracheal tube and verified by disappearance of pulse wave on BP tracing and asystole/ventricular fibrillation/systolic BP < 25 mm Hg.CPR was performed according to Utstein.Spontaneous regular cardiac rhythm,reappearance of pulse wave and systolic BP> 60 mm Hg lasting for more than 10 min were used as criteria for recovery of spontaneous circulation (ROSC).Eight animals were decapitated and their brains were immediately removed at 0.5,3,6,9 and 24 h (T1-5) after BOSC respectively.2% Evans blue 2 ml/kg was injected Ⅳ 15 min before each time point.Brain water content (wet weight dry weight/wet weight × 100% ) and Evan's brain content in the brain tissue were determined.Results The two groups were comparable with respect to body weight,amount of adrenaline given,duration of precordial cardiac massage and BOSC time.The brain water content and Evan's blue content in the brain tissue were significantly increased after ROSC in beth groups.The cerebral water content was significantly higher after BOSC in group CH than in group PB.There was no significant difference in Evan's blue content in the brain tissue after ROSC between the two groups.Conclusion Cardiac arrest and CPR cause cerebral edema and increase permeability of BBB.Pentobarbital shows higher degree than chloral hydrate in terms of inhibition of cerebral edema.While there is no significant difference in the influence on permeability of BBB between the two anesthetics.