小儿中阿片类药物对丙泊酚镇静药效学的影响

Influence of opioids on propofol pharmacodynamics during anesthesia induction in pediatric patients

目的基于小儿麻醉诱导期脑电双频指数(BIS)及丙泊酚效应室质量浓度的变化,定量分析阿片类药物对丙泊酚镇静药效学的影响。方法将45例不用术前药的患儿随机分为3组:C组静脉输注0.9%氯化钠溶液,R组静脉输注瑞芬太尼0.3μg.kg-1.min-1,S组静脉输注舒芬太尼0.02μg.kg-1.min-1。30min后开始丙泊酚靶控输注,起始效应室质量浓度为1μg/mL,逐渐递增至4μg/mL。于基础时间点、阿片类药输注30min后、丙泊酚达预设浓度1min后及意识消失即刻记录BIS、效应室质量浓度、改良警觉-镇静(OAA/S)评分。结果 3组的BIS与丙泊酚效应室质量浓度及OAA/S评分呈正相关。R组、S组患儿意识消失时的BIS值分别为77±6、76±7,均显著高于C组的66±7(P值均<0.05)。R组、S组的丙泊酚效应室质量浓度分别为(1.2±0.5)、(1.1±0.7)μg/mL,均显著低于C组的(2.4±0.5)μg/mL(P值均<0.05)。R组、S组从开始输注丙泊酚至意识消失的时间分别为(4.8±2.3)、(4.6±2.7)min,均显著短于C组的(8.3±1.6)min(P值均<0.05)。R组、S组50%患儿意识消失的丙泊酚效应室质量浓度(EC50)分别为1.02、0.98μg/mL,均显著低于C组的1.98μg/mL(P值均<0.05);R组和S组50%患儿意识消失时的BIS(BIS50)分别为85、83,均显著高于C组的75(P值均<0.05)。结论复合使用阿片类药物后,患儿丙泊酚意识消失的EC50降低。阿片类药物与丙泊酚相互作用可使意识消失时的BIS值升高,因此BIS值不能很好地反映患儿的镇静状态。

Objective To quantitatively analyze the influence of opioids on propofol pharmacodynamics based on the changes of bispectral index（BIS）and propofol effect-site concentration during induction in pediatric patients.Methods Forty-five unpremedicated pediatric patients were randomly assigned to three groups：0.9% NaCl（group C）,0.02 μg·kg-1·min-1 sufentanil（group S）,and 0.3 μg·kg-1·min-1remifentanil（group R）.Thirty minutes later the patients were then given target-controlled effect site concentration infusion of propofol,with the initial concentration being 1 μg/mL,which increased gradually to 4 μg/mL.The target effect-site concentration of propofol,BIS value,observer＇s assessment of alertness/sedation（OAA/S）score and hemodynamic variables were observed at base-line time point,30 min after administration of opioids,1 min after propofol concentration reached the predefined level,and immediately after loss of consciousness.Results BIS was significantly correlated with OAA/S score and propofol effect-site concentration in all groups.The BIS values at loss of consciousness were 77±6 and 76±7 in R and S groups,respectively,which were significantly higher than that of group C（66±7,P0.05）;propofol effect-site concentrations were（1.2±0.5）and（1.1±0.7）μg/mL,respectively,which were significantly lower than that of group C（[2.4±0.5] μg/mL,P0.05）.The interval between administration of propofol and loss of consciousness in groups R and S were（4.8±2.3）and（4.6±2.7）min,respectively,which were significantly shorter than that in（[8.3±1.6] min,P0.05）.The median effective concentration（EC50）of propofol for loss of consciousness was 1.02 μg/mL in group R,0.98 μg/mL in group S,both were significantly lower than that in group C（1.98 μg/mL,P0.05）.The BIS50 values at loss of consciousness were 85 and 83 in group R and S,respectively,both were significantly higher than that in group C（75,P0.05）.Conclusions When sufentanil or remifentanil is combined with propofol,the EC50 value of propofol at loss of consciousness decreases.Reaction of opioids with propofol can increase BIS value at loss of consciousness,suggesting that BIS is not a good indicator of sedation.