右美托咪定伍用麻黄碱对老年患者血流动力学的影响

The hemodynamic effect of combined treatment of ephedrine and dexmedetomidine on the old patients

目的探讨右美托咪定(Dex)伍用麻黄碱对老年患者血流动力学的影响。方法择期拟行膝关节置换术的患者60例,65~80岁,ASAⅡ~Ⅲ级,随机分为3组(C组,E1、E2组)。C组Dex 200μg加入生理盐水至50 m L,负荷量0.4μg/kg,10 min泵注完毕,然后以0.4μg/(kg·h)维持。E1、E2组在配制的50 m L Dex中分别加入盐酸麻黄碱注射液15 mg和30 mg,其他用法与C组相同。泵注开始前测量心率(HR)和平均血压(MBP)为基础值(T0),给药后5 min(T1)、10 min(T2)、15 min(T3)、20 min(T4)、30 min(T5)的HR和MBP,并且记录给药后30 min内每组HR、MBP最低值,到达最低值的时间(抵谷时间),计算基础值与最低值的差值和百分比。结果与E2组比较,C组和E1组从T2时刻起,HR和MBP逐渐下降,呈递减趋势,下降幅度C组大于E1组,HR和MBP抵达最低值时间C组快于E1组;E2组从T0时刻开始,HR和MBP无明显变化。结论伍用麻黄碱可预防Dex所致心动过缓和低血压,可延缓HR和血压的下降时间和减小下降幅度,每200μg Dex加入30 mg麻黄碱剂量合适。

Objective To investigate the hemodynamic effect of combined treatment of ephedrine and dexmedetomidine on old patients. Methods Sixty patients（ ASA Ⅱ-Ⅲ）,scheduled for total knee replacement were randomly divided into 3 groups（ n = 20 in each group）,control group（ Group C）,low doses ephedrine plus dexmedetomidine（ Group E1） and high doses ephedrine plus dexmedetomidine（ Group E2）. Dexmedetomidine（ 200 μg） was given in Group C,while ephedrine of 15 mg and 30 mg were plus in Group E1 and E2. MAP and HR were recorded at baseline（ T0）,5 min（ T1）,10 min（ T2）,15 min（ T3）,20 min（ T4） and 30 min（ T5） after administration. The lowest value of HR and MBP,and how long it took to reach the lowest value in each group were recorded thirty minutes after giving medicine. The difference and percentage of the base and minimum values were calculated. Results Compared with Group E2,the HR and MBP were gradually reduced from T2 in Group C and E1,and it was more prominent in Group C than Group E1. The HR and MBP reached the lowest value in the Group C faster than Group E1. The HR and MBP showed no significant change in Group E2 since T0. Conclusion Ephedrine can prevent Dex-induced bradycardia and hypotension,delay the decline in heart rate and blood pressure,and reduce the rate of decline.