丙泊酚镇静下瑞芬太尼抑制喉罩置管和气管插管心血管反应的半数有效浓度比较

目的 测定抑制喉罩通气道LMA-Fastrach、LMA-Proseal置管和气管插管心血管反应的瑞芬太尼半数有效浓度以及比较置管期间相应脑电双频谱指数(BIS)的变化.方法 择期全麻下行胆囊切除术患者63例,美国麻醉医师协会(ASA)I～II级,按置管类型的不同随机均分为T、F、P 3组,每组21例.4 mg/L启动并调整丙泊酚靶控,使得BIS稳定于45～55,之后按Minto药代模式设置并启动瑞芬太尼效应室靶控,5 min后给0.6 mg/kg罗库溴铵,2 min后置管:T组气管插管,F组LMA-Fastrach置管,P组放置LMA-Proseal.比较患者麻醉诱导前、诱导后平均动脉压(MAP)、心率(HR)值及置管前后的BIS变化.记录置管前1、2min及置管后5min内的MAP、HR值以判定患者有无心血管反应.应用Dixon-Mood序贯法计算抑制3种置管心血管反应的瑞芬太尼的半数有效浓度(EC50).结果 与麻醉诱导前相比,3组麻醉诱导后MAP、HR均明显下降MAP:T、F、P组麻醉诱导前后分别为(87.9+10.5)mmHg比(71.6+9.0)mm Hg,(91.8+8.8)mm Hg比(73.5±9.9)mm Hg,(87.2±10.2)mm Hg比(70.9+8.6)am Hg,HR:T、F、P组麻醉诱导前后分别为(78.8±11.6)次/min比(68.7+8.5)次/min,(74.8±10.3)次/min比(64.1±6.7)次/min,(76.7±8.2)次/min比(67.3±8.3)次/min,1 mm Hg=0.133 kPa,P<0.05],而置管前后的BIS值则无变化(P>0.05).瑞芬太尼抑制3组置管心血管反应的半数有效浓度依次为T组4.47 μg/L、F组4.78 μg/L、P组2.05 μg/L.结论 Minto模式靶控测得瑞芬太尼抑制3种置管心血管反应的EC50 LMA-Fastrach置管略高于气管插管,LMA-Proseal置管则最低.

The medium effective concentration of remifentanil for blunting cardiovascular responses to new laryngeal masks insertion versus tracheal intubation under propofol sedation

Objective To measure the medium effective concentration (EC50) of remifentanil for blunting cardiovascular response to placement of LMA-Fastrach, LMA-Proseal and tracheal intubation, and to compare the change of brain bispectral index (BIS) during these procedures. Methods Sixty-three patients (ASA I-II) scheduled for cholecystectomy under general anesthesia were enrolled. According to different options of intubation, all the patients were randomly allocated into three groups (n=21 each): group T by laryngoscope and tracheal intubation, group F by LMA-Fastrach and group P by LMA-Proseal.Initially, a target plasma concentration of 4 mg/L propofol was chosen, and was adjusted to maintain BIS between 45 and 55. Then, the effect-site concentration of remifentanil was started at designed concentration according to Minto's pharmacokinetic model. Five minutes later, 0.6 mg/kg (2 ED95) rocuronium was given, and intubation was performed 2 min after rocuronium administration. The pre- and post-induction mean arterial pressure (MAP), heart rate (HR) and BIS were compared among these groups. MAP and HR at 1 and 2 min pre-intubation and at 5 min post-intubation were also recorded to evaluate whether there was a cardiovascular response in these patients. Subsequently, the EC50 of remifentanil for blunting the cardiovascular response to 3 options of intubation was calculated using the Dixon-Mood up- and down- sequence. Results Compared with pre-induction, all the patients in 3 groups experienced significantly lower post-inductive MAP and HR MAP of pre- and post-induction in T, F, P groups were (87.9±10.5) mm Hg vs (71.6±9.0) mm Hg, (91.8±8.8)mm Hg vs (73.5±9.9) mm Hg, (87.2±10.2) mm Hg vs (70.9±8.6) mm Hg, HR of pre- and post-induction in T, F, P groups were (78.8±11.6) min-1 vs (68.7±8.5) min-1,(74.8±10.3) min-1 vs (64.1±6.7) min-1, (76.7±8.2) min-1 vs (67.3±8.3) min-1,1 mm Hg=0.133 kPa, P<0.05] but BIS unchanged basically (P>0.05). The EC50 of remifentail for blunting cardiovascular response to intubation was 4.47 μg/L for group T, 4.78 μg/L for group F and 2.05 μg/L for group P, respectively. Conclusion EC50 of remifentail for blunting cardiovascular responses to intubation as shown by Minto's model appears slightly higher in LMA-Fastrach than that in tracheal intubation, and the lowest is in LMA-Proseal intubation.