创伤性脑水肿的在体研究

Study on traumatic brain edema in vivo

目的 探讨在体研究创伤性脑水肿的方法。 方法 选择１５ 个频率点，测量大鼠中度颅脑创伤后伤区组织的电阻抗，分析脑水肿的变化。 结果 伤后早期细胞外液电阻（Ｒｅ） 明显下降，细胞内液电阻（Ｒｉ） 无明显变化，ＲｅＲｉ 也明显下降；６ ｈ 后Ｒｅ 略有升高，Ｒｉ 明显下降，ＲｅＲｉ明显增加；伤后２４ ～７２ ｈ 脑水肿达高峰，伤后７ ｄ 基本恢复。 结论 伤后早期电阻抗的变化提示发生了血管源性脑水肿，伤后６ ｈ 电阻抗变化表明细胞内液增多，细胞毒性脑水肿形成。多频率点电阻抗测试可在体反映创伤性脑水肿的发生发展。

Objective To explore a method of observing traumatic brain edema in vivo. Methods After a moderate brain trauma in rats, the electrical impedance of the traumatic brain tissue was measured at different 15 frequency pots. The changes of brain edema were then analyzed. Results The resistance of extracellular fluid(Re) and Re/Ri significantly decreased in the early stage of trauma. However, there were no significant changes in resistance of intracellular fluid. Six hours later, Re increased slightly, Ri decreased markedly; and Re/Ri elevated significantly. The brain edema reached a summit of severity 24 72 hours after trauma, and recovered 7 days later. Conclusions In the early period of trauma, the change of the electrical impedance indicated an appearance of vasogenic brain edema. Six hours later, the change showed an increase of extracellular fluid and an occurrence of cytotoxic brain edema. The test of multi frequency electrical impedance suggested the existence and development of traumatic brain edema in vivo.