摘要
目的 分析丙泊酚靶控输注(TCI)诱导时患者意识消失及痛反应消失的理论血液半数有效浓度(EC50)和效应室EC50以及听觉诱发电位指数值(AAI50)的变化。方法 20例无神经精神疾病、无药物与酒精滥用史及听力正常的择期全麻手术成年患者(ASAⅠ～Ⅱ级),实施丙泊酚TCI诱导,起始靶浓度为1μg/ml,每隔2分钟递增0.5μg/ml,直至病人镇静警觉评分(OAA/S)为0,观察效应室浓度和听觉诱发电位指数(AAI)的变化。根据概率分析估计丙泊酚的理论血液及效应室EC50和AAI50。结果丙泊酚TCI诱导时,意识消失(OAA/S≤2)的血液和效应室EC50分别为2.17μg/ml(95％的可信限为2.05～2.38 μg/ml)和1.64 μg/ml(95％的可信限为1.52～1.91μg/ml),AAI50为37.8(95％的可信限为32.2～40.9);痛反应消失(OAA/S=0)的血液和效应室EC50分别为2.32 μg/ml(95％的可信限为2.20～2.54μg/ml)和1.74 μg/ml(95％的可信限为1.62～2.00μg/ml),AAI50为27.7(95％的可信限为23.4～30.4)。结论 丙泊酚TCI系统可通过预测血液及效应室浓度提示患者意识和痛反应是否消失。AAI值随丙泊酚血液及效应室浓度增加而逐渐降低,是预测麻醉浓度的良好指标。
Objective To predict blood and effect-site concentration of propofol and the auditory evoked potential index at the time points when 50% of patients fall into unconsciousness or had no response to pain during induction (EC50 and AAI50). Methods Twenty ASA Ⅰ -Ⅱ patients scheduled for elective surgery were included in this study. Patients with psychoneural diseases, hearing disturbances or chronically use of any sedatives,hypnotics,opioids or alcohol were excluded. Anesthesia was induced with propofol delivered by a Diprifusor target-controlled infusion(TCI). The target concentration (Ct) of propofol was increased step-by-step with 1μg/ml each step until modified OAA/S sedation score became zero. At each step,Ct increased by 0. 5μg/ml,and the interval between the two steps was 2 min. Changes of propofol concentration in blood and effect-site (calculated and displayed by Diprifusor) and AAI were recorded at the same times. Probit analysis was used to estimate population values for predicting blood and effect-site propofol concentrations and AAI at the clinical end-points of loss of consciousness(T1) and no response to pain(T2). Results The predicted blood and effect-site EC50 at T1 (OAA/S score@2) were 2. 17 and 1. 64 μg/ml with 95% confidence intervals of 2. 05-2. 38 and 1. 52-1. 91μg/ml respectively,and AAI50 was 37. 8% (95% confidnce intervals: 32. 2-40. 9). The predicted blood and effect-site EC50 at T2 (OAA/S score=0) were 2. 32 and 1. 74μg/ml with 95% confidence intervals of 2. 20-2. 54 and 1. 62-2. 00μg/ml respectively,and AAI50 was 27. 6(95% confidence intervals:23. 4-30. 4). Conclusion Unconsciousness and lack of response to pain may be predicted by the propofol concentration and EC50 provided by Diprifusor TCI system. AAI decreases gradually as the propofol concentration in blood and effect-site increases, which is an indicator to predict the depth of anesthesia.
出处
《临床麻醉学杂志》
CAS
CSCD
2004年第10期601-603,共3页
Journal of Clinical Anesthesiology
基金
无锡市科技局资助(编号CS2002003)
