一种硬膜外局部低温方法的降温效能和安全性研究

目的应用自制降温线圈发展一种硬膜外局部低温治疗方法，对其降温效能和安全性进行评估。方法SD大鼠随机分为常温对照组（Nor组）、硬膜外局部低温组（LH组）和全身低温组（SH组），对LH组和SH组分别实施硬膜外局部降温和全身降温，观察降温前后同侧脑温、对侧脑温、肛温以及呼吸、心率、血压变化，降温后24h对各组大鼠进行神经功能评测，取脑组织标本行光镜、电镜检查，并检测脑组织水、钠、钾离子含量和血脑屏障通透性。结果降温后，LH组大鼠的降温侧脑温在数分钟内从（36．5±0．3）℃下降到（31．4±0．4）℃并维持稳定，其对侧脑温和肛温无明显下降，R、HR和MABP无明显变化；SH组降温后双侧脑温、肛温均出现降低，降温后HR下降。降温后，LH组和SH组大鼠神经功能评分正常，光镜和电镜下脑组织无损伤表现，其脑组织水、钠、钾离子含量和血脑屏障通透性与常温对照组比较无统计学差异。结论应用这种硬膜外局部低温方法可以达到与全身降温一样的效果，且不会引起生命体征波动及对脑组织产生急性损害。

Efficacy and Security Study of an Epidural Cooling Method to Induce Local Brain Hypothermia

Objective To develop an epidural cooling method to induce local brain hypothermia using a self-made cooling coil, and to evaluate its efficacy and security. Methods SD rats were randomly divided into normal temperature group （Nor）, local hypothermia group （LH） and systemic hypothermia group （SH）. The local brain hypothermia and systemic hypothermia were induced respectively, and the ipsilateral, contralateral brain temperature, rectal temperature, blood pressure, respiratory and heart rate from each group were assessed before and after cooling. The neurological evaluation and microscopic examination were carried out at 24 h follow cooling, and the brain water, Na^＋ , K^＋ content and blood-brain barrier permeability were also detected. Results In LH group, local brain hypothermia was produced within minutes from（36.5 ± 0.3）℃ to （31.4 ±0.4） ℃ in the ipsilateral hemisphere after cooling, while the contralateral brain temperature, rectal temperature, R, HR and MABP were not significantly altered during cooling. In SH group, the decrease of bilateral brain and rectal temperature as well as HR was observed after cooling. There were no significant difference in NSS score, brain water, Na^＋ , K^＋ and Evans Blue content among groups, no structural alterations were found in brain tissue of LH and SH group neither. Conclusions This epidural cooling method can achieve the effect of brain hypothermia as well as systemic cooling, and dose not cause fluctuations in vital signs and acute neuronal injury.