环境低温对非麻醉猪失血性休克血流动力学及氧代谢的影响

目的 探讨环境低温对非麻醉猪失血性休克血流动力学及氧代谢的影响.方法 沈阳军区总医院动物中心提供的巴马香猪16头随机(随机数字法)分为:室温休克组和低温休克组,每组8头.按30 mL/kg放血建立失血性休克模型,记录建模前及建模后4h内不同时点的核心体温、心率、平均动脉压、中心静脉压、心输出量、混合静脉血氧饱和度及血气等变化,并计算氧摄取率、氧供指数和氧耗指数.采用SPSS11.0软件包行计量资料的成组t检验.结果 模型建立后室温组动物的核心体温略有下降,环境低温使核心体温下降更加明显.低温组动物的病死率较室温组明显增加(P＜0.05).休克导致氧供和氧耗明显下降.室温组和低温组的血流动力学指标、氧供和氧耗的差异无统计学意义,但两者在pH值、乳酸和氧提取率上差异具有统计学意义(P＜0.05).结论 环境低温加重了失血性休克后的氧代谢紊乱,使预后进一步恶化.

Effects of environmental hypothermia on hemodynamics and oxygen metabolism in unanesthetized swine model of hemorrhagic shock

Objective To investigate the effects of environmental hypothermia on hemodynamics and oxygen metabolism in unanesthetized swine model of hemorrhagic shock.Methods A total of 16 Bama pigs provided by animal experiment centre of the General Hospital of Shenyang Military Command were randomized into two groups ( n =8,each):ambient temperature (A) and hypothermia ( H ).Venous blood (30 mL/kg) was continously withdrawn over 15 minutes to establish hemorrhagic shock model.Core temperature,heart rate,mean arterial pressure,central venous pressure,cardiac output,saturation of mixed venous blood and blood gas analysis were recorded at the baseline and different hemorrhagic shock time.DO2I and VO2I,and the O2 extraction ratio (O2ER) were calculated.Results Core body temperature in group A decreased slightly after hemorrhagic shock model had established and environmental hypothermia resulted in more reduction in core body temperature.The mortality rate was significantly higher in group H (50％) than in group A (0％) (P ＜0.05).DO2I and VO2I decreased significantly after hemorrhage.No difference was found in hemodynamics,DO2I and VO2I between group A and group H,but the difference of pH,lactic acid and O2ER were significant between the two groups (P ＜ 0.05 ).conclusions Environmental hypothermia aggravated the disorder of oxygen metabolism after hemorrhagic shock,which was associated with poor prognosis.