靶控输注舒芬太尼降低腹部手术切皮时七氟醚MACBAR的封顶效应

目的]观察靶控输注（TCI）不同浓度的舒芬太尼对腹部手术切皮时抑制交感反应七氟醚最低肺泡浓度值（MACBAR）的影响,以探讨舒芬太尼出现封顶效应的靶控浓度.方法]择期腹部手术患者120例,随机按舒芬太尼不同浓度分别以0 ng/mL、0.12 ng/mL、0.18 ng/mL、0.24 ng/mL、0.30 ng/mL和0.36n g/mL分组命名为S0～S5组,每组20例.所有患者用丙泊酚（ 3.5 μg/mL）、瑞芬太尼（ 4 ng/mL）和罗库溴胺（0.6 mg/kg）行麻醉诱导,气管插管后立即停用丙泊酚和瑞芬太尼,吸入七氟醚、60%笑气和40%氧气,各组分别将七氟醚和舒芬太尼调至设定浓度.记录麻醉诱导前、切皮前以及切皮后的平均动脉压（MAP）、心率（HR）和脑电双频指数（BIS） 值.根据序贯法半数效量公式计算每组的七氟醚MACBAR.结果]S0～S5组七氟醚MACBAR分别为2.3%、1.6%、1.1%、0.9%、0.8%和0.7%.与S0组比较,各组七氟醚MACBAR均明显降低（P＜0.05）;与S1组比较,S2～S5组七氟醚MACBAR均明显降低（P＜0.05）; S3～S5各组七氟醚MACBAR相比较没有统计学差异（P＞0.05）.结论]靶控输注舒芬太尼呈剂量依赖性降低腹部手术切皮时七氟醚MACBAR值,舒芬太尼靶浓度大于0.18 ng/mL时,七氟醚MACBAR降低不明显,表现出封顶效应.

Ceiling Effect of Target Controlled Infusion of Sufentanil for Decreasing MACBAR of Sevoflurane at Skin Incision in Patients Undergoing Abdominal Surgery

Objective] To observe the effect of different concentration of sufentanil by target-ontrolled infusion（TCI） on minimum alveolar concentration（MACBAR） of sevoflurane for inhibiting adrenergic responses at skin incision of abdominal sur-gery, and explore the TCI concentration of sufentanil while ceiling effect appears. Methods] Totally 120 ASA Ⅰ-Ⅱ patients （aged 20-60 years old） undergoing elective abdominal surgery were randomly divided into So group（sufentanil 0 ng/mL）, SO group（sufentanil 0.12ng/mL）, SO group （sufentanil 0. 18ng/mL）, S3 group （sufentanile 0. 24ng/mL）, SO group （sufentanile 0.30ng/mL） and SO group（sufentanil 0.36ng/mL） with 20 cases in each group. Propofol 3.5μg/mL, remifentanil 4ng/ml and rocuronium 0.6mg/kg were used for anesthesia induction of all patients. After tracheal intubation, propofol and remifentanil were immediately stopped. Sevoflurane, 600% nitrous oxide and 40% oxygen were inhaled. The concentration of sevoflurane and sufentanil in each group were regulated to the setting concentration. Mean arterial pressure（MAP）, heart rate（HR） and bispectral index（BIS） were recorded before anesthesia induction and before and after skin incision. MACBAR of sevoflurane in each group was calculated by using median effective dose formula of sequential method. Results]MACBAR of sevoflurane in So-SO group were 2.3%, 1. 6%, 1. 1%, 0. 9%, 0. 8% and 0.7%, respectively. Compared with S0 group, MACBAR of sevoflu-rane in S1-S5 group decreased significantly（ P〈0.05）. Compared with 81 group, MACBAR of sevoflurane in S2-S5 group de-creased significantly（ P〈0. 05）. There was no significant difference in MACBAR of sevoflurane among S2-S5 goups （ P〉0.05）. Conclusion] TCI of sufentanil can reduce MACBAR of sevoflurane at skin incision in patients undergoing abdominal sur-gery in a dose-dependent manner. When the target concentration of sufentanil is more than 0. 18ng/mL, the decreasing of MACBAR of sevoflurane is not obvious and the ceiling effect of sufentanil appears.