高晶体-高胶体渗透压混合液对失血性休克时大鼠脑血流及脑组织含水量的影响

Effects of hypertonic-hyperoncotic solution and Ringer' s lactate solution on cerebral blood flow and cerebral water content during hemorrhagic shock in rats

目的 比较ＨＨＳ和乳酸林格氏平衡液（ＬＲ）对大鼠失血性休克模型脑血流和脑组织含水量的影响。方法１４只大鼠随机分为２组，采用动脉放血的方法复制失血性休克模型，分别在休克后输入 ＬＲ或 ＨＨＳ。于休克前、休克后、容量复苏后即刻和 ３０ ｍｉｎ测其脑血流量和脑组织含水量。脑血流量采用９９ｍＴｃ标记同位素法测定，脑组织含水量用烘干前后称重的方法测定。结果 容量复苏后即刻，二组动物脑血流量增加（Ｐ＜０．０５）。３０ｍｉｎ后，ＬＲ组的脑血流量降低，明显低于复苏后即刻的脑血流量和同时刻 ＨＨＳ组的脑血流量（Ｐ＜０．０５），ＨＨＳ组则无明显减少。ＨＨＳ组脑组织含水量在复苏后降低（Ｐ＜０．０５），ＬＲ组动物的脑组织含水量则增加（Ｐ＜０．０５）。结论 小容量ＨＨＳ可增加脑血流量、减轻休克后脑组织水肿。ＬＲ不能有效地恢复脑血流量，并且可加重脑组织水肿。

Objective To compare the effects of hypertonic-hyperoncotic solution (HHS) and Ringer's lactate solution(RL) on cerebral blood flow and cerebral water content during hemorrhagic shock in rats. Methods Fourteen SD rats of either sex weighing 270-410g were randomly divided into two groups of seven animals each: HHS group and RL group. All rats were subjected to hemorrhage and MAP was maintained at 5.32 kPa for 60 min and subsequently the animals were resuscitated with HHS or RL until MAP returned to baseline. Cerebral blood flow and cerebral water content were determined before and after shock, and immediately and 30 min after resuscitation. Cerebral blood flow was measured with isotope 99mTc and cerebral water content was measured by the difference between wet and dry weight of the brain.Results 1. The average amount of HHS infused during resuscitation was (3.4 + 0.5) ml'kg~' and the average amount of RL infused was (40.4?.6) ml-kg'' .The difference was extremely significant between the groups(P< 0.01). 2. Cerebral blood flow decreased by 35.1% (RL group) and 34.8% (HHS group) during shock and increased by 47.4% (RL group) and 54.5% (HHS group) immediately after resuscitation but at 30 min after resuscitation decreased again in RL group while in HHS group there was no significant change. 3. Cerebral water content decreased by 8.0% immediately after resuscitation and 7.7% at 30 min after resuscitation in HHS group as compared with that during shocks while in RL group it increased after resuscitation and was significantly higher than that during shock. Conclusions With small amount of HHS cerebral blood flow can be increased and cerebral edema prevented or mitigated during hemorrhagic shock. RL can not effectively restore cerebral blood flow and it makes cerebral edema worse.