限制性输液复苏法对失血性休克孕兔血流动力学变化的影响

目的 探讨限制性输液复苏法对失血性休克孕兔血流动力学变化及血清肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)含量变化的影响.方法 将20只妊娠中晚期新西兰大白兔分为2组,分别采用生理盐水传统输液复苏法(PNL组)及限制性输液复苏法(PLH组),每组10只.建立非控制性失血性休克模型,实验设计分为休克期(0～30 min),院前复苏期(30～90 min)及院内复苏期(90～180 min).休克期:两组孕兔均接受颈动脉放血至平均动脉压(MAP)为40～45 mm Hg(1 mm Hg=0.133 kPa).院前复苏期:剪开两组孕兔孕囊血管放血,复制活动性出血模型,然后PNL组和PLH组孕兔分别接受生理盐水及自身血复苏至MAP为80、60 mm Hg.院内复苏期:两组孕兔均接受手术止血及输血、输液治疗.比较两组孕兔各时间点血流动力学、TNF-α及IL-6含量的变化,记录输血、输液量及生存率.结果 (1)120 min时,PLH组孕兔呼吸、心率分别为(66±16)、(235±41)次,PNL组分别为(78±16)、(291±37)次,两组分别比较,差异有统计学意义(P＜0.01);PLH组孕兔MAP和中心静脉压(CVP)分别为(80.4±7.2)mm Hg、(8.0±4.4)cm H2O,PNL组孕兔分别为(72.5±8.2)mm Hg、(5.8±3.1)cm H2O,两组分别比较,差异也有统计学意义(P＜0.01);(2)两组孕兔血清TNF-α、IL-6含量休克后均升高,且在240 min时达高峰,PLH组孕兔血清TNF-α、IL-6含量分别为(105±67)、(118±51)ng/L,PNL组分别为(280±160)、(311±240)ng/L,两组比较,差异有统计学意义(P＜0.01),且PLH组孕兔血清TNF-α、IL-6含量在480 min时已降至正常;(3)PLH组输血、输液量在院前复苏期分别为(16.0±2.2)、(39.0±5.5)ml,在院内复苏期分别为(28.0±6.7)、(90.0±7.1)ml,PNL组在院前复苏期分别为(31.0±8.2)、(85.0±7.9)ml,在院内复苏期分别为(37.5±9.4)、(140.0±24.8)ml,两组比较,差异也有统计学意义(P＜0.05);(4)PLH组孕兔24、72 h的生存率分别为100%、90%;PNL组为80%、60%,两组比较,差异有统计学意义(P＜0.01).结论 限制性输液有利于失血性休克孕兔血流动力学指标的恢复,缓解血清TNF-α、IL-6含量升高的程度,从而提高了动物生存率.

Effect of limited volume resuscitation on hemodynamic changes in pregnant rabbit with hemorrhagic shock

OBJECTIVE: To determine the effects of two fluid resuscitation strategies on the changes of hemodynamic variables, serum concentration of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in a clinically relevant model of uncontrolled hemorrhagic shock in pregnant rabbits. METHODS: Hemorrhagic shock was induced by bleeding via carotied artery, followed by transection of a medium vessel in gestational sac. Experimental design consisted of three phases, shock phase (0-30 min), prehospital phase (30-90 min) and hospital phase (90-180 min). Twenty pregnant rabbits were randomly divided into two groups (n=10 /group), aggressive fluid resuscitation group (PNL group) and limited volume resuscitation group (PLH group). In the shock phase, animals were hemorrhaged by blood withdrawal to mean arterial pressure (MAP) of 40-45 mm Hg (1 mm Hg=0.133 kPa) via carotid artery. In the prehospital phase, a medium vessel in the gestational sac was transected, then the animals in the PNL group and PLH group were resuscitated with 0.9% normal saline (NS) and shed blood to MAP of 80, 60 mm Hg respectively. In the hospital phase, bleeding was controlled by surgical intervention and all the animals were reinfused with shed blood and NS to MAP 80 mm Hg. Hemodynamic variables and respiration rate were monitored and blood samples were collected for TNF-alpha and IL-6 measurement, and finally subsequent volume resuscitation and survival rate were recorded. RESULTS: (1) At 120 min, the respiration rate and heart rate in the animals assigned to PLH group was (66+/-16) bpm, (235+/-41) bpm respectively, which were significantly lower than those in PNL group (P<0.01), while MAP and central venous pressure in the PLH group was (80.4+/-7.2) mm Hg, (8.0+/-4.4) cm H2O, respectively, which were significantly higher than those in PNL group (P<0.01); (2) The serum concentration of TNF-alpha, IL-6 of all the animals were markedly increased after hemorrhagic shock, and peak at 24 min. The serum concentration of TNF-alpha, IL-6 in animals assigned to PLH group were (105+/-67) ng/L, (118+/-51) ng/L respectively, which were significantly lower than those in PNL group (P<0.01). The serum concentration of TNF-alpha, IL-6 in the animals assigned to PLH group were decreased to normal at 480 min; (3) The subsequent blood transfusion volume and NS resuscitation volume in PLH group in prehospital phase were (16.0+/-2.2) ml, (39.0+/-5.5) ml respectively, while those in hospital phase were (28.0+/-6.7) ml, (90.0+/-7.1) ml respectively, which were significantly lower than those in PNL group (P<0.05); (4) The 24 and 72 hours survival rate in the animals assigned to PLH group were 100%, 90% respectively; which were significantly higher than those in PNL group (P<0.01). CONCLUSION: Limited volume resuscitation improves thermodynamic changes of pregnant rabbit, attenuates the increase of serum concentration of TNF-alpha, IL-6, and results in higher survival rate. Limited volume resuscitation is an ideal means for hemorrhagic shock resuscitation in pregnant rabbit.