熵指数监测麻醉镇痛的有效性

Efficacy of spectral entropy in measurement of depth of anesthesia and noxious stimulation

目的评价熵指数监测麻醉深度与反映伤害性刺激的效应。方法ASAⅠ-Ⅱ级择期手术患者45例,按照静注芬太尼剂量随机分为A组(1μg/kg)、B组(3μg/kg)和C组(5μg/kg)(n=15)。诱导开始先给予不同剂量芬太尼,3 min后靶控输注技术输注异丙酚,当其效应室浓度(CE)达3.5μg/mL时行气管插管,维持此浓度输注至切皮后5 min。记录静注芬太尼前及注射后2、3 min,异丙酚CE达1、2.5、3.5μg/mL时插管前、插管时及插管后1、3、5 min,切皮前及切皮后0.5、1、3、5 min各时点的反应熵(RE)、状态熵(SE)、心率(HR)和平均动脉压(MAP)。结果给芬太尼3 min后,三组RE和SE均较各自基础值减小,且均值随芬太尼剂量增大而减小;在插管时和切皮后0.5 min,三组RE和SE都明显升高,但插管后1 min与切皮后5 min均回落到刺激前水平;三组间RE和SE的波动在异丙酚CE达1.0μg/mL后已无差别。结论熵指数可以准确监测麻醉的镇静程度,但不能有效反映芬太尼对伤害性刺激的抑制程度。

Objective To investigate the efficacy of spectral entropy measurement in reflection of depth of anesthesia and noxious stimulation. Methods Forty-five patients of ASA Ⅰ or Ⅱwere randomly divided into three groups （ n = 15）. Group A, B and C received fentanyl 1, 3 and 5 μg/kg, respectively, 3 min before target controlled infusion （TCI） of propofol. Intubation was performed when the effect-site concentration（ CE ） reached 3.5 μg/mL, which was maintained until 5 min after incision. Response entropy （RE） , State entropy （SE） as well as heart rate （HR） , mean arterial pressure （MAP） were measured at the time points of before fentanyl and 2, 3 min after fentanyl, every CE of propofol steps, before intubation, immediately and 1,3,5 rain after intubation, before skin incision, and 0.5, 1, 3, 5 rain after skin incision, respectively. Results Three minutes after receiving fentanyl, the values of RE and SE in the three groups decreased significantly in a dose-dependent manner, and increased obviously at the same degree during intubation and after skin incision. The values recovered to the level before stress stimulation 1 min after intubation and 5 min after skin incision. There were no differences in the fluctuation of RE and SE among the three groups when the CE of propofol reached 1.0 μg/mL. Conclusion Spectral entropy may effectively reflect the depth of anesthesia, but not analgesia during anesthesia.