右美托咪定用于下肢手术镇静的适宜负荷剂量探讨

Exploration of Proper Load Dosage of Dexmedetomidine for Lower Limbs Operation

目的:观察右美托咪定不同剂量对下肢手术患者的影响,探讨右美托咪定用于下肢手术镇静的适宜负荷剂量。方法:选择50例美国麻醉医师协会(ASA)分级Ⅰ～Ⅱ级择期在腰硬联合麻醉下行下肢手术的患者,年龄18～60岁,手术时间2～3h,体质量指数(BMI)18～29kg/m,随机分为5组,即对照组(D0)和右美托咪定组(D1、D2、D3、D4),每组10例。麻醉平面稳定后(若麻醉平面不能确定就以手术医师切皮不痛为标准),开始静脉泵注右美托咪定,D1、D2、D3、D4组剂量分别为0.25、0.50、0.75、1.00μg/kg,D0组为生理盐水对照组,给药时间均为10min。记录泵药前(T0)和泵药后5min(T5)、10min(T10)、30min(T30)、60min(T60)、90min(T90)及术后2h(T120)、4h(T240)各时间点的心率(HR)、脉搏血氧饱和度(SpO2)、平均动脉压(MAP)、Narcotrend指数、Ramsay评分。结果:与T0比较,D1～D4组在T10、T30、T60、T90时HR均降低(P<0.05),在T5、T10时MAP升高(P<0.05),在T10、T30时Narcotrend指数下降(P<0.05),在T10、T30、T60时Ramsay评分升高(P<0.05)。结论:右美托咪定负荷剂量0.50～0.75μg/kg用于下肢手术镇静,能达到满意的镇静效果,患者血流动力学较稳定且无呼吸抑制。在给药30min后镇静效果较明显,随着剂量的增大,镇静时间延长。

To observe the effect of different dosages of dexmedetomidine on patients underwent lower limbs operation, and to investigate the proper load dosage of dexmedetomidine. METHODS： 50 ASA Ⅰ - Ⅱ level patients who were selected to be operated in the lower limbs with lumbar anesthesia, aged 18 to 60, with operation period of 2-3 h and BMI of 18-29 kg/m, were randomly divided into 5 groups （n= 10）, i.e. control group （D0） and dexmedetomidine groups（D1, D2, D3, D4）. After the anesthesia got stable, if the＇surface of the anesthesia was not sure, intravenous pump of dexmedetomidine had been started by the standard of no pain during skin incision, and the dosage of the D1, D2, D3 and D4 groups were 0.25 μg/kg, 0.50 μg/kg, 0.75 μg/kg and 1.00 μg/kg, respectively. Do group was normal saline control group. The administration time of each group was 10 minutes. HR, SpOt, MAP, Narcotrend index and Ramsay score were recorded before administration （T0） and 5 min （T5）, 10 min （T10）, 30 min （T30）, 60 min （T60） and 90 min （T90） after administration, 2 h （T120） and 4 h （T240） after operation. RESULTS： Compared with To, HR index of group D1-D4 all decreased at T10, T30, T60 and T90（P〈0.05）. MAP index of group D1-D4 all increased at T5 and T10（P〈 0.05） ; Narcotrend index of group D1-D4 decreased at T10 and T30（P〈0.05） ; Ramsay score of group D1-D4 increased at T10, T30, T60 （P〈0.05）. CONCLUSION： The dosage of dexmedetomidine ranging from 0.50 to 0.75 μg/kg for lower limbs operation sedation shows stable hemodynamic, and it can offer the satisfied calmness without breath control in the operation. The calming effect is very obvious 30 min after the administration, the time of calmness extends as the dosage increases.