七氟醚麻醉下瑞芬太尼抑制小儿切皮反应的血浆靶浓度

Target plasma concentration of remifentanil to block somatic and cardiovascular responses to skin incision in children

目的确定七氟醚麻醉下瑞芬太尼抑制小儿切皮时躯体和心血管反应的血浆靶浓度。方法择期全麻手术小儿75例,年龄2～5岁,ASAⅠ级,随机均分为五组,七氟醚吸入诱导后,采用Minto药代动力学模型靶控输注瑞芬太尼,血浆靶浓度分别为1、2、3、4、5ng/ml(R1～R5组),维持呼气末七氟醚浓度稳定在1.5%,15min后开始切皮。切皮即刻,小儿发生体动为躯体反应阳性;MAP或HR较切皮前升高或增快>15%为心血管反应阳性。Probit法计算瑞芬太尼抑制50%和95%患儿切皮即刻躯体和心血管反应的有效血浆靶浓度(CP50和CP95)。结果五组瑞芬太尼抑制切皮时躯体反应有效构成比分别为0/15、5/15、12/15、15/15、15/15;抑制心血管反应有效构成比分别为0/15、2/15、8/15、13/15、14/15。结论在1.5%七氟醚麻醉下,瑞芬太尼抑制2～5岁小儿切皮时躯体反应的CP50及其95%可信区间为2.29(1.92～2.59)ng/ml,CP95及其95%可信区间为3.53(3.02～5.03)ng/ml;抑制心血管反应的CP50及其95%可信区间为2.89(2.46～3.29)ng/ml,CP95及其95%可信区间为4.99(4.19～7.18)ng/ml。

Objective To investigate the target plasma concentration（CP50 and CP95）of remifentanil to block somatic and cardiovascular responses to skin incision with sevoflurane anesthesia in children.Methods Seventy-five children,ASA Ⅰ,aged 2-5 years for elective surgery under general anesthesia were enrolled in this study.After induction with sevoflurane,patients were equally randomized into five groups to receive a target plasma concentration of remifentanil with the Minto model：1,2,3,4,and 5 ng/ml（group R1-R5,respectively）.The end-tidal concentration of sevoflurane was maintained to 1.5% for 15 min,then the surgical was incised.A positive somatic response was defined as noticeable body movement in response to skin incision.Positive response of cardiovascular system was defined as mean arterial pressure（MAP）or heat rate（HR）increased by 15%.Results The incidence of successful block somatic response was 0,33,80,100 and 100%,respectively,and the incidence of successful block cardiovascular responses was 0,13,53,87 and 93%,respectively.Conclusion The CP50 and CP95 of remifentanil to block somatic response to skin incision during sevoflurane 1.5% anesthesia in children were 2.29 ng/ml and 3.53 ng/ml.The CP50 and CP95 of remifentanil to block cardiovascular responses were 2.89 ng/ml and 4.99 ng/ml,respectively.