控制性与非控制性失血性休克早期液体复苏的对比研究

Comparative study of early liquid resuscitation in controlled and uncontrolled hemorrhagic shock

目的比较在失血已控制及失血未控制两种状态下常规液体复苏治疗失血性休克的效果,探索早期液体复苏对策。方法健康雄性SD大鼠28只,随机分为对照组(n=8)、失血已控制休克组(CHS组,n=10)及失血未控制休克组(UHS组,n=10)。CHS组及UHS组大鼠股动脉放血,使血压在15min内降至30mmHg,然后截断3组大鼠尾根部,对照组及CHS组立即结扎止血,UHS组不予处理使其自然流血。模拟战创伤实际情况,将动物分为院前期(30～90min)、医院救治期(90～150min)及康复期(150min～72h)3个阶段。院前期通过输液将大鼠血压维持在60mmHg;医院救治期结扎出血灶,输血、输液维持大鼠血压至90mmHg;康复期观察至72h。监测平均动脉压(MAP)、中心静脉压(CVP)、心功能、血气分析及血细胞比容(Hct)、血乳酸水平等,观察记录出血量、补液量及动物存活时间。结果根据实验设计,通过液体复苏使CHS组及UHS组大鼠院前期及医院救治期MAP分别维持在60mmHg及90mmHg。CHS组及UHS组同一时相MAP及CVP均无显著差异。院前期UHS组大鼠Hct明显低于CHS组。自院前期开始,UHS组大鼠血乳酸水平即持续性升高,而医院救治期以后CHS组血乳酸水平升高不明显。从医院救治期开始UHS组心率及最大心室内压上升速度明显低于CHS组。液体复苏后CHS组动物酸中毒及低氧血症得到明显纠正,但UHS组仍持续处于低氧血症及酸中毒状态。CHS组院前期补液量(44.5±10.1ml/kg)明显低于UHS组(74.5±11.4ml/kg,P<0.01)。CHS组及UHS组72h死亡率分别为30%及80%。结论较失血已控制的休克而言,对失血未控制的休克进行快速复苏可导致出血量增加、血液稀释、心功能损害及死亡率增加。

Objective To compare the effects of routine liquid resuscitation on hemorrhagic shock in uncontrolled and controlled states in order to probe into the strategy of liquid resuscitation. Methods Twenty-eight healthy male SD rats were randomly divided into three groups： control （n=8）, controlled hemorrhagic shock （CHS, n=10）, and uncontrolled hemorrhagic shock （UHS, n=10）. In the CHS and UHS groups, the rats were made to bleed from the femoral artery till the blood pressure declined to 30 mmHg within 15 minutes. There after, the roots of the tails of the rats in the three groups were cut. The trunks of the tails were ligated to stop the bleeding in the control and CHS groups, but it was not ligated in the UHS group, and no treatment was given. Imitating war condition： the animals were divided into three phases： pre-hospital phase （30-90 minutes）, hospital phase （90-150 minutes）, and recovering phase （150 minutes to 72 hours）. The blood pressure was maintained at 60mmHg in the pre-hospital phase by transfusion. The hemorrhagic spot was ligated in the hospital phase, and the blood pressure was maintained at 90 mmHg by blood and fluid transfusions. In the recovering phase, the observation time was maintained up to 72 hours. The mean arterial pressure （MAP）, central venous pressure （CVP）, heart function, blood gas analysis, corpuscular volume, and blood lactic acid were determined. The amount of bleeding, quantity of infusions, and survival time of animals were observed and recorded. Results Based on the design of the experiment, the MAP of rats in the CHS and UHS groups was maintained at 60 mmHg and 90 mmHg in the pre-hospital phase and hospital phase by liquid resuscitation, respectively. There was no significant difference in the MAP and CVP between the CHS and UHS groups. However, the Hct of the rats in the UHS group in the pre-hospital phase was dearly lower than that in CHS. Starting from the pre-hospital phase, blood lactic acid content of rats in the UHS group there was no obvious increased continuously, while in the CHS group, there was no obvious increase after the hospital phase. The increasing heart rate and the maximum intraventricular pressure in the UHS group were clearly lower than that in the CHS group starting from the hospital phase. Acidosis and hypoxemia rats of the CHS group were improved significantly after fluid resuscitation. However, the rats in UHS group were still in the state of acidosis and hypoxemia. The quantity of infusion fluid in the CHS group in the pre-hospital phase （44.5±10.1ml/kg） was lower than that of the UHS group （74.5±11.4ml/kg, P〈0.01）. The mortality at 72 hours was 30% and 80%, respectively. Conclusion Compared with the controlled hemorrhagic shock group, rapid liquid resuscitation in rats with uncontrolled hemorrhage can cause a greater amount of blood loss, hemodilution, damage to cardiac function, and increased mortality.