Relationship of implicit memory and amnesia effect of oral midazolam premedication / 临床麻醉学杂志

ABSTRACT

Objective To study the relationship of implicit memory and amnesia effect of oral midazolarn premedication and toobserve its anterograde amnesia, the effect on short-term memory and the onset time and out come of retrograde amnesia. Methods60 patients with ASA I - Ⅱ status undergoing abdomen and limb operations were divided into 3 groups with 20 cases each. Group Aoral midazolam 7.5mg;Group Boral 15mg;Group Cplacebo. 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. ConclnsionOral 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.