摘要：
Objective To investigate effects of different doses of dexmedetomidine (Dex) on the sedation and anterograde amnesia in patients undergoing operation on bythus.Methods Two hundred patients,ASA Ⅰ-Ⅱ,aged 20-60,101 males and 99 females were dministered spinal-epidural anesthesia combined with Dex,undergoing operation on bythus without caesarean section.After Dex 1 μg/kg was infused intravenously 10 min (group De0 was infused intravenously the same volume of physiological saline),according to different maintenance doses of Dex,they were divided into four groups by random number table method:group De0 (group physiological saline),group De1 (0.2 μg·kg1·h-1),group De2 (0.4 μg·kg-1·h-1),group De3 (0.6 μg·kg-1·h-1).By observer's assessment of alertness/sedation(OAA/S) method,the sedation degree of the Dex was evaluated at 5 min(T1),10 min(T2),15 min (T3),20 min(T4),25 min(T5),30 min(T6),40 min(T7),50 min(T8).After 24 h of operation,the anterograde amnesia degree of Dex was assessed.Results When the OAMS scores of group De0 of sedation were all(5.00±0) at T2,T3,T4,T5,T6,T7,and T8 point,with the time of Dex infused intravenously longer and the dose of Dex increased,the OAA/S scores of group De1,group De2 and group De3[The OAMS scores of group De1 of sedation was(3.15±0.37) at T2 point,(3.26±0.44) at T3 point,(2.70±0.66) at T4 point,(2.55±0.60) at T5 point,(2.40±0.60) at T2 point,(2.05±0.76) at T7 point,(2.02±0.73) at T8 point,The OAA/S scores of group De2 of sedation was (3.10±0.64) at T2 point,(2.95±0.51) at T3 point,(2.35±0.67) at T4 point,(2.25±0.55) at T5 point,(2.10±0.45) at T6 point,(1.60±0.50) at T7 point,(1.65±0.49) at T8 point;The OAMS scores of group De3 of sedation was (3.10±0.31) at T2 point,(2.65±0.49) at T3 point,(1.95±0.39) at T4 point,(1.90±0.45) at T5 point,(1.75±0.44) at T6 point,(1.20±0.62) at T7 point,(1.25± 0.64) at T8 point] became smaller in a dose-dependent manner(P＜0.05).When there were 50 cases of the no anterograde amnesia in the group De0,the degree of anterograde amnesia of group De1,group De2 and group De3 [there were 4 cases on total amnesia,35 cases part amnesia,11 cases no amnesia in the group De1,there were 15 cases on total amnesia,29 cases part amnesia,6 cases no amnesia in the group De2,but there were 29 cases on total amnesia,19 cases part amnesia,2 cases no amnesia in the group De3] increased markedly in a dose-dependent manner (P＜0.05).Conclusions Dex had better function of the sedation and anterograde amnesia in a dose-dependent manner.%目的 观察不同剂量右美托咪定(dexmedetomidine,Dex)对下腹部手术患者术中镇静程度及顺行性遗忘作用的影响. 方法 选择美国麻醉医师协会(ASA)分级Ⅰ～Ⅱ级,年龄20岁～60岁,在腰麻硬脊膜外联合阻滞麻醉下复合Dex行下腹部手术(剖宫产术除外)的患者200例,其中男101例,女99例.采用随机数字表法进行分组,根据给予生理盐水或Dex维持剂量的不同分为4组(每组50例):生理盐水组(De0组)、0.2 μg·kg1·h-1组(De1组)、0.4 μg· kf-1·h-1组(De2组)、0.6 μg· kg-1·h-1组(De3组).采用改良警觉/镇静观察评分(observer's assessment of alertness/sedation,OAA/S)法,观察Dex泵入后5 min(T1)、10 min(T2)、15 min (T3)、20 min(T4)、25 min(T5)、30 min(T6)、40 min(T7)和50 min(T8)各时间点患者镇静程度及术后24 h顺行性遗忘情况. 结果 De0组各时间点的OAMS法评分均为(5.00±0)分,De1组、De2组、De3组随着时间的延长,泵入Dex剂量的逐渐增大,OAMS评分逐渐减小(P＜0.05):De1组T2～T8评分依次为(3.15±0.37)、(3.26±0.44)、(2.70±0.66)、(2.55±0.60)、(2.40±0.60)、(2.05±0.76)、(2.02±0.73)分;De2组T2～T8评分依次为(3.10±0.64)、(2.95±0.51)、(2.35±0.67)、(2.25±0.55)、(2.10±0.45)、(1.60±0.50)、(1.65±0.49)分;De3组T2～Ts评分依次为(3.10±0.31)、(2.65±0.49)、(1.95±0.39)、(1.90±0.45)、(1.75±0.44)、(1.20±0.62)、(1.25±0.64)分.De0组无遗忘病例为50例;De1组、De2组、De3组无遗忘病例明显减少(P＜0.05):De1组完全遗忘4例,部分遗忘35例,无遗忘11例;De2组完全遗忘15例,部分遗忘29例,无遗忘6例;De3组完全遗忘29例,部分遗忘19例,无遗忘2例. 结论 Dex具有良好的镇静以及一定的顺行性遗忘作用,且呈剂量依赖性.
