罗哌卡因在超声引导肋间神经阻滞用于乳腺良性肿块切除术中的半数有效浓度

Median effective concentration of ropivacaine for ultrasound-guided intercostal nerve block in benign breast lumpectomy

目的测定罗哌卡因在超声引导下肋间神经阻滞用于乳腺良性肿块切除术中的半数有效浓度(EC50)。方法选择拟行单侧乳腺良性肿块切除术女性患者32例,ASAⅠ或Ⅱ级,在超声引导下用罗哌卡因行肋间神经阻滞麻醉。罗哌卡因浓度根据序贯法确定,初始浓度为0.25%,若阻滞效果完全,下一例患者降低浓度0.05%;若阻滞效果不完全,下一例患者升高浓度0.05%。采用Probit概率单位回归法计算罗哌卡因的EC50及其95%可信区间(CI),观察记录患者一般情况及不良反应发生情况。结果患者退出3例,完成试验共29例,年龄(38.1±10.7)岁,体重指数(23.7±3.2)kg·m^(-2)。神经阻滞完成至手术开始时间为(14.2±3.3)min,手术持续时间为(101.6±24.4)min。罗哌卡因用于超声引导下肋间神经阻滞的EC50为0.210 9%(95%CI:0.150 1%~0.268 9%)。未见严重不良反应发生。结论罗哌卡因在超声引导肋间神经阻滞用于乳腺良性肿块切除术中的EC50为0.210 9%。

AIM To determine the median effective concentration （ECs0） of ropivacaine for ultrasound- guided intercostal nerve block in benign breast lumpectomy. METHODS Thirty-two female patients underwent unilateral benign breast tumor resection with ASA I or II were selected and performed intercostal nerve block anesthesia with ropivacaine under ultrasound guidance. The concentration of ropivacaine was determined by up- and- down sequential trial and the initial concentration was 0.25%. If the blocking effect was complete, the concentration reduced 0.05% for the next patient. If the blocking effect was not complete, the concentration was elevated 0.05% for the next patient. The EC50 and its 95% confidence interval （CI） of ropivacaine for ultrasound- guided intercostal nerve block were calculated by using Probit regression method. The general situation and adverse reactions of the patients were observed and recorded. RESULTS Among all cases, 3 patients were out and 29 patients completed the trial. The patients aged （38.1 ± 10.7） years and the body mass index was （23.7 ± 3.2） kg.m-2. The duration time from nerve block completed to operation started was （14.2 ± 3.3） min. The duration of operation was （101.6±24.4） min. The ECso of ropivacaine for uhrasound-guided intercostal nerve block was 0.210 9% （95%CI： 0.150 1%-0.268 9%）. No serious adverse reactions occurred. CONCLUSION The EC50 of ropivacaine is 0.210 9%, when it used for ultrasound-guided intercostal nerve block in patients undergoing benign breast lumpectomy.