经尿道前列腺电切术老年患者鞘内注射不同局麻药的药效学

目的 探讨经尿道前列腺电切术老年患者鞘内注射不同局麻药的药效学.方法 择期拟在脊椎-硬膜外联合阻滞下行经尿道前列腺电切术的老年患者90例,ASA分级Ⅰ～Ⅲ级,年龄69～82岁,体重指数＜30 kg/m2,随机分为3组(n=30):左旋布比卡因组(L组)、罗哌卡因组(R组)和布比卡因组(B组)分别于蛛网膜下腔注射0.5%左旋布比卡因、0.5%罗哌卡因、0.5%布比卡因.采用序贯法进行试验,初始剂量分别为7、10、6 mg,相邻剂量比均为0.9.阻滞有效,则下一例采用低一级剂量;阻滞无效,则下一例采用高一级剂量.阻滞有效的标准为:蛛网膜下腔注药后20 min内感觉阻滞平面达T10.计算3种局麻药半数有效剂量(ED50)及其95%可信区间(95%CI).结果 经尿道前列腺电切术老年患者鞘内注射左旋布比卡因、罗哌卡因和布比卡因阻滞的ED50及其95%CI分别为6.781(6.561～7.024)mg、9.135(8.670～9.616)mg和5.170(5.012～5.333)mg.左旋布比卡因、罗哌卡因和布比卡因的效价比为0.76∶0.57∶1.00.结论 经尿道前列腺电切术老年患者鞘内注射左旋布比卡因、罗哌卡因和布比卡因阻滞的效价比为0.76∶0.57∶1.00.

Pharmacodynamics of different local anestheties administered intrathecally for elderly patients undergoing transurethral resection of the prostate

Objective To investigate the pharmacodynamics of different local anesthetics administered intrathecally for elderly patients undergoing transurethral resection of the prostate (TURP). Methods Ninety ASA Ⅰ - Ⅲ elderly patients, aged 69-82 yr, with body mass index less than 30 kg/m2 , undergoing TURP under combined spinal-epidural anesthesia, were randomly divided into 3 groups ( n = 30 each): levobupivacaine group (group L), ropivacaine group (group R) and bupivacaine group (group B). Group L, R and B received intrathecai (IT) 0.5 % levobupivacaine, 0.5 % ropivacaine and 0.5 % bupivacaine respectively. The initial dose was 7,10 and 6 mg in group L, R and B respectively. The ratio of two successive doses was 0.9. If the upper sensory block reached T10 within the 20 min after IT injection, the IT analgesia was considered to be effective. The median effective dose (EDs0) and 95 % confidence interval (95 % CI) were calculated by Dixon. Results The ED50 and 95% CI of levobupivacaine, ropivacaine and bupivacaine were 6.781 (95% CI 6.561-7.024) mg, 9.135 (95%CI8.670-9.616) mg and 5.170 (95% CI 5.012-5.333) ng respectively. The relative potency ratio between levobupivacaine, ropivacaine and bupivacaine is 0.76∶0.57∶1.00. Conclusion The relative potency ratio be tween levobupivacaine, ropivacaine and bupivacaine is 0.76∶0.57∶1.00.