犬脑选择性深低温对全身重要器官生理功能的影响

Extracerebral effects of selective profound cerebral hypothermia in dogs

目的 :探讨脑选择性降温技术的安全性。 方法 :通过单侧颈总动脉低温灌注法 ,对 10只犬进行了选择性脑部降温。观察了降温过程中生命体征的变化 ,术前及术后血常规、电解质、肝肾功能以及心脏、肝脏酶谱的变化。 结果 :10只犬均实现了选择性脑部降温。脑温最低达 (17.8± 1.8)℃ ,直肠温保持在 (32 .5± 2 .0 )℃以上。4只犬于术后 1～ 3d死亡 ,6只长期存活。降温过程中犬的生命体征有明显改变 ,随温度回升而恢复正常。术后血常规、电解质、肝肾功能、酶谱与术前无显著差异。 结论 :采用动脉内低温灌注 ,可选择性快速降低脑温。降温使脑干心血管中枢功能抑制 ,但经开放椎动脉后可迅速纠正。该技术对全身重要器官生理功能无明显损害。

Objective: To determine whether the technique of selective brain cooling was safe or not. Methods: With the technique of cold infusion through common carotid artery, 10 dogs received selective brain cooling. We observed the changes of vital signs through the cooling and rewarming course. After operation, we examined dog′s blood cell counts, biochemical parameters, liver and kidney functions and enzymes of brain and heart. Results: Selective brain cooling was successfully performed in all 10 dogs. The lowest brain temperature reached (17.8±1.8)℃ while the rectum temperature maintained at above (32.5±2.0)℃. Four dogs died 1 to 3 days after operation, and 6 dogs survived. During the cooling, the dogs′ vital signs changed significantly. These signs returned to normal when brain temperature was raised. After operation, the blood routine examinations, evaluation of biochemical parameters and liver, kidney functions showed no significant difference compared with that of pre operation. Conclusion: These findings demonstrate that profound selective cooling of the brain can be achieved by the technique of intra arterial cold perfusion. The cooling of the brain stem will suppress the neural centre of circulation and ventilation, but it can be treated by reopening of the vertebral artery. The technique has no obvious impairment to extracerebral organs.