术前口服咪唑安定的遗忘作用与内隐记忆的关系

目的 观察咪唑安定的遗忘作用与内隐记忆的关系，同时调查术前口服咪唑安定有无逆行性遗忘作用，对短期记忆的影响及顺行性遗忘的起效时间和效果。方法 60例择期下腹部及下肢手术病人分为三组，每组20例：A组口服咪唑安定7．5mg；B组口服咪唑安定15mg；C组为对照组。入室后服药，然后行硬膜外腰麻联合麻醉。观察脑电、95％谱边界频率（SEF）和双频谱指数（BIS）；根据国际标准化进行镇静分级与评分；采用图片识记和术后测试模糊辨听率的方法进行记忆与遗忘的调查及内隐记忆调查。结果 （1）A、B两组病人从服药后20分钟开始镇静评分较服药前明显降低并与C组比较差异有显著意义。但A、B两组之间在镇静觉醒评分和镇静开始时间差异无显著意义。（2）术后6小时遗忘率调查，A组服药后30分钟，B组服药后20分钟遗忘率较服药前显著升高，并保持在70％－80％的高水平，两组间差异无显著意义。而C组遗忘率 始终为0。（3）三组间模糊辨听率差异无显著意义。（4）服药期间短期记忆10分钟遗忘率三组均为0。（5）服药后30分钟A、B两组的BIS与SEF均较服药前明显降低，但仍维持在80Hz，两组间差异也无显著意义。结论 术前口服咪唑安定7．5mg，30分钟后即可产生良好的顺行性遗忘作用，增大剂量并未明显提高其疗效。咪唑安定不产生逆行性遗忘作用。药物作用期间即刻记忆完整而长期记忆受损，对记忆的影响仅限于外显记忆而不包括内隐记忆。因此这种遗忘作用尚不能完全达到防止麻醉中知晓的目的。

Relationship of implicit memory and amnesia effect of oral midazolam premedication

Objective To study the relationship of implicit memory and amnesia effect of oral midazolarn premedication and to observe its anterograde amnesia, the effect on short-term memory and the onset time and out come of retrograde amnesia. Methods 60 patients with ASA I - Ⅱ status undergoing abdomen and limb operations were divided into 3 groups with 20 cases each. Group A:oral midazolam 7.5mg;Group B:oral 15mg;Group C:placebo. The patients received combined spinal-epidural anesthesia after oral midazolam. The parameterns of EEG, SEF 95 %, BISwere collected at the same time and the degree and remark of sedation were dome according to OAA/S. The amnesia and implicit memory were investigated with pictures and muddy identified hearing rate 6 hours after operation. Results (1)Twenty min following drug ad dministration the remarks of sedation of group A and B were significantly loWver than that before and that of group C, Which was not significently different between group A and B. ( 2)The amnesia rates tested six hrs after surgery were significantly higher at 30min in group A, 20min in group B than those before treatment and were kept at 70%-80% levels, which in group C was remained zero. (3)The muddy identified hearing rate was not different significantly, among the three groups. (4) The short-term memory was all 100%during the period of drug action. (5)BIS and SEF 95% Were lower 30min after the treatment and all kept at 80 Hz and 20 Hz, which were not different remarkably between group A and B. Conclnsion Oral midazolam 7. 5mg has a good effect on anterograde amnesia 30min after treatment, which may not be improved with increament in dosage. It does not lead to retrograde amnesia. The long-term memory, but not short-term memory, was impaired by midazolam. It only affects the explicit memory. Oral premnedication with midazolam can not prevent the awareness during operation totally.