3种麻醉药对大鼠右心室血流动力学的影响

Effects of three anesthetics on right ventricular hemodynamics in rats

目的通过比较3种常见麻醉药对大鼠右心室血流动力学的影响,探寻对大鼠右心室血流动力学影响较小的麻醉药物.方法按随机数字表法将成年雄性SD大鼠分成4组(n=5),分别腹腔注射10%水合氯醛3.5mL/kg(水合氯醛组)、20%乌拉坦6mL/kg(乌拉坦组)、10%水合氯醛与20%乌拉坦1:1混合液5mL/kg(混合液组)、2%戊巴比妥钠5mL/kg(戊巴比妥钠组).动物麻醉后留置右心室和颈动脉测压导管,应用PowerLab生物信号数据采集和分析系统,连续记录大鼠麻醉后2h内的心率(HR)、呼吸频率(RR)、右心室收缩压(RVSP)、右心室内压最大上升速率(RV+dp/dtmax)、右心室内压最大下降速率(RV-dp/dtmax)、收缩压(SBP)、舒张压(DBP)和平均动脉压(MAP).结果麻醉过程中,戊巴比妥钠组大鼠右心室血流动力学各项指标变化均较小,HR维持在(369±15)^(405±16)次/min,RR维持在(69±6)^(75±9)次/min,RVSP维持在(31.4±2.7)^(33.7±1.0)mmHg(1mmHg≈0.133kPa),RV+dp/dtmax维持在(1267.2±319.0)^(1414.8±202.2)mmHg/s,RV-dp/dtmax维持在(-1151.5±80.6)^(-976.6±73.2)mmHg/s,麻醉效果稳定.10%水合氯醛可使大鼠RVSP、RV+dp/dtmax、血压降低,RV-dp/dtmax升高〔RVSP(mmHg):20.3±0.8~23.7±0.2,RV+dp/dtmax(mmHg/s):678.3±56.8~715.0±84.1,RV-dp/dtmax(mmHg/s):-675.0±73.7^-624.5±34.7〕.20%乌拉坦可引起大鼠RV-dp/dtmax降低,RVSP、RV+dp/dtmax升高〔RV-dp/dtmax(mmHg/s):-1248.2±117.9^-1058.5±206.8,RVSP(mmHg):36.4±0.6~37.6±0.8;RV+dp/dtmax(mmHg/s):1398.8±89.8~1557.4±62.2〕,HR随时间延长呈下降趋势,90min时HR明显低于15min时(次/min:394±9比443±35〕.混合液可导致大鼠RVSP在60min时与15min比显著升高(mmHg:34.4±1.1比30.3±4.2,P<0.05),SBP、DBP、MAP不稳定,均呈先升高后下降的趋势.结论与10%水合氯醛、20%乌拉坦、水合氯醛与乌拉坦1:1混合液麻醉药相比,2%戊巴比妥钠对大鼠右心室血流动力学的影响较小,比较适合用于右心相关的实验研究中.

Objective To explore the best anesthetic with less effect on the right ventricular hemodynamics of rats by comparing the effects of three anesthetics on right ventricular hemodynamics of rats.Methods Sprague-Dawley(SD)rats were randomly divided into four groups(n=5)and given intraperitoneal injection of 10%chloral hydrate 3.5 mL/kg(chloral hydrate group),20%urethane 6 mL/kg(urethane group),1∶1 mixture of 10%chloral hydrate and 20%urethane 5 mL/kg(mixture group)and 2%pentobarbital sodium 5 mL/kg(pentobarbital sodium group),respectively.Then,tubes were placed into right jugular vein and left carotid artery,and using PowerLab biological signal data collection and analysis system,the heart rate(HR),respiratory rate(RR),right ventricular systolic pressure(RVSP),maximum rate of rise of right ventricular pressure(RV+dp/dt max),maximum rate of decline of right ventricular pressure(RV-dp/dt max),carotid artery systolic blood pressure(SBP),diastolic blood pressure(DBP),and mean arterial pressure(MAP)in rats 2 hours after anesthesia were continuously recorded.Results During anesthetics,the indexes of right ventricular hemodynamics of rats in pentobarbital sodium group were little changed.HR maintained at(369±15)-(405±16)bpm,RR maintained at(69±6)-(75±9)times/min,RVSP maintained at(31.4±2.7)-(33.7±1.0)mmHg(1 mmHg≈0.133 kPa),RV+dp/dt max maintained at(1267.2±319.0)-(1414.8±202.2)mmHg/s,RV-dp/dt max maintained at(-1151.5±80.6)-(-976.6±73.2)mmHg/s;the anesthesia effect was stable.However,rats in the 10%chloral hydrate group had decreased RVSP,RV+dp/dt max,blood pressure and increased RV-dp/dt max[RVSP(mmHg):(20.3±0.8)-(23.7±0.2),RV+dp/dt max(mmHg/s):(678.3±56.8)-(715.0±84.1),RV-dp/dt max(mmHg/s):(-675.0±73.7)-(-624.5±34.7)].Rats in 20%urethane group had decreased RV-dp/dt max and increased RVSP,RV+dp/dt max[RV-dp/dt max(mmHg/s):(-1248.2±117.9)-(-1058.5±206.8),RVSP(mmHg):(36.4±0.6)-(37.6±0.8),RV+dp/dt max(mmHg):(1398.8±89.8)-(1557.4±62.2)],HR decreased with time,and significantly decreased at 90 minutes compared with 15 minutes(bpm:394±9 vs.443±35).Mixture resulted in the increased RVSP at 60 minutes compared with that at 15 minutes(mmHg:34.4±1.1 vs.30.3±4.2)and the instability of SBP,DBP and MAP,which increased first and then decreased.Conclusion Compared with the other two kinds of anesthetics,2%pentobarbital sodium has the less effect on right ventricular hemodynamics of rats,which is more suitable for scientific research on right heart.