右美托咪定注射液在女性患者中年龄因素对有效镇静量效关系的影响

Adequate sedation with dexmedetomidine injection in female patients:a dose-response study by age group

目的观察年龄因素对女性患者单次泵注右美托咪定注射液的有效镇静量效关系的影响。方法选取择期腰硬联合麻醉下进行下肢手术女性患者,根据不同年龄分为3组,A组26例(20~35岁)、B组31例(40~60岁)和C组29例(65~79岁)。3组患者待进行腰硬联合麻醉后,开始泵注右美托咪定,各组每例患者的给药剂量由二阶段改良序贯法决定,A组、B组和C组分别以1.0,1.0和0.6μg·kg^(-1)为初始单次剂量泵注,15 min泵完。泵注完毕后对患者进行1次警觉/镇静评分(OAA/S)评分,随后每5 min评估1次,持续15 min。使用Probit逻辑回归法计算3组右美托咪定有效镇静的半数有效剂量(ED50)及其相应的95%置信区间(CI)。结果 A组、B组和C组右美托咪定有效镇静的ED50分别为0.98,0.96,0.66μg·kg^(-1);相应的95%CI分别为0.93~1.03,0.92~1.00和0.63~0.69μg·kg^(-1)。与A组和B组比较,C组ED50明显降低(P<0.05)。A组出现心动过缓2例(7.69%),B组出现心动过缓4例(12.90%),C组有心动过缓2例(6.89%),差异无统计学意义(P>0.05)。结论中、青年女性患者单次泵注右美托咪定有效镇静的ED50无差异,而老年女性患者的ED50显著低于中青年女性患者。

Objective To investigate the influence of age on the median effective dose（ ED50） of single- dose dexmedetomidine to induce adequate sedation in female patients. Methods Female patients scheduled for elective lower limb surgery under combined spinal- epidural anesthesia were enrolled. Patients were divided into three groups depending on age（ 26 patients aged 20 to 35 years as group A,31 patients aged40 to 60 years as group B and 29 patients aged 65 to 79 years as group C）. After spinal anesthesia,a bolus of dexmedetomidine was administered intravenously over 15 minutes. The dose for each subsequent was predetermined using a two- stage modified up and down method of dixon and the initial dose in group A,group B and group C was started from1. 0,1. 0 and 0. 6 μg·kg^（-1）,respectively. The observer＇s assessment of alertness / sedation（ OAA / S） scale would be assessed upon the completion of the loading dose,then assessed every 5 minutes for 15 minutes. The ED50 of dexmedetomidine with 95% confidence interval（ CI） was analyzed by a probit logit regression analysis. Results The ED50 ofdexmedetomidine with 95% CI for providing adequate sedation were 0. 98（ 0. 93- 1. 03） μg·kg^（-1）in group A,0. 96（ 0. 92- 1. 00） μg·kg^（-1）in group B and 0. 66（ 0. 63- 0. 69） μg · kg^（-1）in group C. Compared with group A and group B,the ED50 in group C was markedly smaller（ P〈0. 05）. There were 2 cases of bradycardia in group A（ 7. 69%）,4 cases（ 12. 90%） in group B and 2 cases（ 6. 89%） in group C（ P〉0. 05）. Conclusion The single dose of dexmedetomidine for providing adequate sedation in youth female group was similar with middle- age female group,but elderly female group was smaller than youth and middle- aged female groups.