浅低温对创伤性失血性休克兔凝血功能的影响

Effect of mild hypothermia on the coagulation with traumatic haemorrhagic shock in rabbits

目的：研究浅低温对创伤性失血性休克凝血功能的影响。方法成年健康雄性新西兰兔20只，按照随机数字表法分为两组，每组10只。实验组以颈动脉放血并股骨骨折法建立创伤性失血性休克（ T／HS）模型，对照组实施假手术（仅皮肤切开），两组均依次经历麻醉、冰敷等物理降温诱导浅低温34℃并维持2 h和加热垫、照热灯等物理复温2 h，分别检测休克前（ t0）、休克30 min后（t1）、低温2 h（t2）及复温2 h（t3）的血常规及血栓弹力图主要参数，记录T、HR、SI、MAP、HGB及R等相关生理指标，观察两组存活率。结果①两组动物创伤早期（4 h）存活率为100％；在t0时间点两组MAP、HGB、HR、R及SI比较差异均无统计学意义（ P＞0．05）。在t1、t2、t3时间点实验组MAP、HGB显著低于对照组（ P＜0．01）；在t1时间点实验组HR、R、SI明显高于对照组（P＜0．01），在t2时间点实验组SI高于对照组（P＜0．01）。对照组MAP、HR、R、SI水平在各时间点均无变化（P＞0．05）。②在t1时间点实验组r、MA低于对照组（P＜0．05）；K值与对照组比较差异无统计学意义（P＞0．05）。在t2时间点实验组r、MA低于对照组（P＜0．05）；K值与对照组比较差异无统计学意义（ P＞0．05）。在各时间点两组Angle、CI比较差异无统计学意义（ P＞0.05）。③在t0时间点两组PLTs比较差异无统计学意（P＞0．05）。在t1、t2、t3时间点实验组PLTs均比对照组小（P均＜0．05）。在t2、t3时间点两组PLTs均明显减少（P均＜0．05）。结论低温与复温均能导致外周血小板数目减少；应用浅低温是安全的，对凝血功能的整体状况没有影响。

Objective To investigated the mild hypothermia effect on coagulation in rabbits subjected to traumatic and hymorrhagic shock.Methods Twenty rabbits were randomly divided into two groups with ten animals in each group： sham control and mild hypothermia （ group T/H ） , traumatic hymorrhagic shock and mild hypothermia （ group T/HS）.Hypothermia was induced by anesthesia induction, with a cold blanket and ice bag.Hemorrhage was induced by bleeding 35% of total blood volume.Capacity for coagulation was measured by thromboelastometry （ TEG ） and then the routine blood, temperature （ T ） , heart rate （ HR ） , shock index （ SI ） , mean arterial pressure （ MAP ） , hemoglobin （ HGB） , respiration （ R） and related physiological indexes were recorded at different time including before shock （ t0 ） , 30 minutes after shock （ t1 ） , 2 hours after hypothermia （ t2 ） , 2 hours after rewarm （ t3 ） .Results ①Baseline parameters were not significantly different among the groups.The survival rates in both groups were 100%.Compared with group T/H, the level of MAP and HGB in group T/HS were significantly lower at t1, t2 and t3 timepoints （all P〈0.01）;while R, HR and SI in group T/HS were significantly higher at t1 timepoint （ all P〈0.01） and SI were significantly higher at t2 timepoint （P〈0.01）.The level of MAP, HR, R and SI of control group didn＇t change significantly in all of the time points.②In group T/HS, the initial clotting time （r）, the maximum amplitude （MA）was reduced compared with group T/H from t1 to t3（all P〈0.05）.The clotformation time （K） was not significantly different at t1 and t2 timepoints （all P〉0.05）.The rate of clot formation （Angle） and the coagulationindex （ CI） in the two groups at t1 -t3 timepoints did not change significantly compared with baseline level （all P〉0.05）.③PLTs in group T/HS were reduced in t1, t2 and t3 timepoints （all P〈0.05） and PLTs in t2 and t3 timepoints were significantly lower than that in t1 timepoint （all P〈0.05）. Conclusion Based on the results of the present study we suggest that mild hypothermia and rewarm can reduce the PLTs, then mild hypothermia can be safely performed after stabilization following the earliest traumatic haemorrhagic shock in rabbits.Mild hypothermia does not significantly effects on the holistic coagulation system in our model.