Gepts E
Department of Anaesthesiology, UVC Sint Pieter, Brussels, Belgium.
Anaesthesia. 1998 Apr;53 Suppl 1:4-12. doi: 10.1111/j.1365-2044.1998.53s111.x.
The development of new short-acting anaesthetic drugs, improved drug assay techniques and the availability of reliable infusion systems opened the field of clinical pharmacokinetics and pharmacodynamics. The tri-exponential drug concentration decay complicates the definition of therapeutic dosage regiments and prevents straightforward prediction of recovery from drug effects. The context-sensitive half-time, the time required for drug blood concentration to decrease to half its value, provides a useful comparative predictor of drug concentration decline after infusion. The effect-site equilibration time contributes to the delay of drug effect and intensifies the disequilibrium between drug blood concentrations and obtained effect following incremental dosage. The rationale for drug infusion is reduction of fluctuating drug concentrations and drug effects. A variability similar to that observed with the use of inhalation agents, must be achieved by the choice of an appropriate pharmacokinetic model. The use of a target controlled infusion device, delivering proportional changes based on pharmacokinetic principles, allows titration of the concentration against clinical effect in individual patients.
新型短效麻醉药物的研发、改进的药物分析技术以及可靠输液系统的出现，开启了临床药代动力学和药效学领域。药物浓度的三指数衰减使治疗剂量方案的定义变得复杂，并阻碍了从药物效应中直接预测恢复情况。情境敏感半衰期，即药物血药浓度降至其值一半所需的时间，为输液后药物浓度下降提供了一个有用的比较预测指标。效应室平衡时间导致药物效应延迟，并加剧了增量给药后药物血药浓度与所获效应之间的不平衡。药物输注的基本原理是减少药物浓度和药物效应的波动。必须通过选择合适的药代动力学模型来实现与吸入麻醉剂使用时观察到的类似变异性。使用基于药代动力学原理进行比例变化给药的靶控输注装置，可以根据个体患者的临床效应滴定浓度。
