硬膜外阻滞辅以丙泊酚闭环靶控镇静

Close loop target control of sedation with propofol during epidural anaesthesia

目的对硬膜外阻滞中以脑电双频指数(BIS)作为反馈的闭环靶控输注丙泊酚镇静的效果和性能进行评价。方法11例ASAⅠ～Ⅱ级择期行下腹部或下肢手术患者,男5例,女6例,年龄28～67岁。硬膜外阻滞期间采用以BIS作为反馈的闭环靶控输注(CLTCI)丙泊酚进行镇静,开始的靶浓度设定为1.5μg/ml,然后每分钟逐步增加或减少0.5μg/ml,直到患者的镇静深度稳定于OAA/S评分3分以下,这时候的BIS值作为反馈变量,通过CLTCI系统自动输注丙泊酚。每5分钟记录血压、心率、BIS和OAA/S评分。记录诱导时间及丙泊酚诱导剂量、丙泊酚总用量、苏醒时间及不良反应,并评价CLTCI系统的性能。结果 所有患者镇静期间血液动力学平稳,无严重呼吸抑制。OAA/S评分3分时平均BIS值76.6。CLTCI系统的偏离性1.9％,精确度7.1％,摆动度4.1％。结论 在硬膜外麻醉期间以BIS为反馈的闭环靶控输注丙泊酚进行清醒镇静是可行的。该系统性能稳定,有临床推广价值。

Objective To evaluate the performance and effect of close loop target infusion (CLTCI) system of propofol for sedation during epidural anaesthesia. Methods Eleven unpremedicated ASA Ⅰ-Ⅱ patients(5 males,6 females,aged 28-67yr) scheduled for selective abdominal and lower extremity surgeries under epidural anaesthesia were included in this study. All patients were sedated with propofol using close loop control system guided by the bispectral index (BIS) during epidural anaesthesia. Initially,propofol was administered at a target blood concentration of 1. 5 μg/ml. This was manually increased or reduced in a step of 0. 5 μg/ml every minute until the sedation target (OAA/S rating of 3) was reached. CLTCI was then initiated using this BIS value as the set-point. BP, HR, BIS, and OAA/S were recorded every five minutes. Induction time, induction dose and total amount of propofol, target propofol concentrations and side effects were noted. The performance of CLTCI was evaluated. Results No patient became apnoeic or hemodynami-cally unstable during sedation. The performance characteristics of the system were excellent, with a median performance error of 1. 9% ,median absolute performance error of 7. 1% ,and wobble of 4. 1%. Conclusion Sedation with propofol using close loop control target system guided by BIS can be used safely and efficiently during epidural anaesthesia.