亚低温治疗急性脑梗死不同复温速率的比较

The effects of re-warming rates of mild hypothermia on rats with ischemic stroke

目的比较亚低温治疗急性脑梗死时，不同复温速率对局灶性脑缺血大鼠颅内压、脑梗死体积及脑组织含水量的影响。方法采用改良线栓法制备大鼠大脑中动脉闭塞（MCAO）模型，手术后即时诱导亚低温（33．5℃），持续24h后开始复温。将32只SD大鼠随机分为1℃／h复温组、0．5℃／h复温组、0．2℃／h复温组和0．1℃／h复温组。复温过程中监测颅内压，复温结束后比较各组脑梗死体积和脑组织含水量。结果刚开始复温（33．5℃）时，4组大鼠颅内压间差异无统计学意义（P〉0．05）。肛温上升到34．5℃时，1℃／h复温组颅内压高于其它3组，差异有统计学意义（P〈0．05）。肛温升至35．5℃时，0．5℃／h复温组也显著高于0．2℃／h复温组和0．1℃／h复温组，差异有统计学意义（P〈0．05）。复温结束（36．5℃）后，4组颅内压都显著升高，与复温前相比差异有统计学意义（P〈0．05），1℃／h复温组和0．5℃／h复温组大鼠脑梗死体积及脑组织含水量都明显高于0．2℃／h复温组和0．1℃／h复温组，差异有统计学意义（P〈0．05），0．2℃／h复温组和0．1℃／h复温组间差异无统计学意义（P〉0．05）。结论复温过快可引起颅内压上升过快，以致脑梗死体积和脑组织含水量增加。复温过程中应控制复温速率，以0．2℃／h的速率复温最佳。

Objective To evaluate the effects of different re-warming rates （ RWR ） of mild hypothermia （MH） on intracranial pressure （ICP） , infarct size （IS） and tissue water content （TWC） in rats with acute cerebral ischemia （ACI）. Methods Thirty-two SD rats were randomly divided rats into 4 groups with different re-warming rates （1℃/h, 0.5℃/h, 0.2℃/h and 0.1℃/h, respectively）. The middle cerebral artery occlusion （MCAO） models were established by using the intra-luminal filament technique. Then all the animals were treated with MH （33.5℃） for 24 h. The ICP, IS and TWC were measured during or after treatment. Results At the beginning of treatment, there was no significant difference with regard to ICP among the four groups （ P 〉 0.05 ）. When rectal temperature （RT） of rats rose to 34.5℃ , ICP in 1℃/h group was obviously higher than that in the other three groups （P〈0.05）. When RT rose to 35.5℃, ICP in 1℃/h and 0. 5℃/h groups was obviously higher than that in 0.2℃/h and 0.1℃/h groups （ P 〈 0.05 ）. At the end of treatment, ICP in four groups were increased obviously （ P 〈0.05）. After re-warming, IS and TWC in 1℃/h and 0.5℃/h groups were much higher than those in 0.2℃/h and 0.1℃/h groups （ P 〈 0.05 ）. Conclusion Fast re-warming may increase intracranial pressure as well as infarct size and tissue water content quickly. The re-warming rate should he controlled for the good effects of MH, and 0.2℃/h may be the best re-warming rate.