缺血后适应用于深低温停循环的神经系统保护效应

Neuroprotection of ischemic postconditioning during deep hypothermic circulatory arrest

目的探索缺血后适应(IPOC)对于深低温停循环(DHCA)相关神经功能损伤的保护效应。方法健康成年巴马香猪12只,随机分为A组(DHCA组)和B组(DHCA IPOC组),每组6只。两组均经颈总动脉和颈内静脉插管建立体外循环,转流并降温至直肠温度15℃,暂停循环90 min后恢复体外循环并复温,先后脱离体外循环、呼吸机辅助,并观察神经系统功能状况至术后7天。B组在停循环后恢复体外循环之初,进行3个轮回的灌注/阻断操作,每个轮回时间为30 s/30 s。结果术后近期两组动物均有一定程度神经系统功能障碍,术后第一天,B组神经系统功能评级明显低于A组,而评分明显高于A组(P <0.05);术后3～7 d,B组神经系统功能评分仍稍高于A组,但无明显统计学差异。至第七天两组动物神经功能状况均渐接近正常。结论 IPOC有助于改善DHCA术后第一天神经系统功能,术后第三天及一周则未见其神经保护效应。进一步评估需假以更大样本量、更长的观测时间及组织病理学等微观分析。

Objective To evaluate the neuroprotective effect of ischemic postconditioning (IPOC) after deep hypothermia circulatory arrest (DHCA) in swines. Methods Twelve healthy adult swines were randomly assigned to group A (control group) or group B (experiment group) .Animals were placed on cardiopulmonary bypass by intubation in the common carotid artery and the internal jugular vein,cooled to 15℃,subjected to 90 minutes of DHCA,rewarmed,weaned from CPB and ventilator in sequence. Neurological function was observed for 7 days after the operation.Results After operation,both two groups of animals had a certain degree of neurocognitive dysfunction.On the first day after operation,the neurological function rating of group B was significantly lower than that in group A,and the score was significantly higher than that in group A (P<0.05) . The neurological function score of group B was still higher than that of group A at 3-7 days after operation,but there was no significant difference.On the seventh day,neurological function of the two groups was almost back to normal. Conclusion IPOC improves neurocognitive function in pig model on the first day after DHCA,but neuroprotective effect was no longer observed on the third day through to the seventh day.