Pharmacokinetic study for target controlled infusion of ketamine and fentanyl

借助于药代动力学原理，可以开发快速获得输注药物的预定血液浓度并随后保持该浓度的输注方案。这种方案的一个例子是氯胺酮的两阶段（2 mg/kg，2 mg/kg/h）输注方案，旨在将血药浓度维持在1.0 μ g/ml。然而，对麻醉药物的需求因患者而异，并且根据手术刺激的性质和强度对个体患者也有所不同。计算达到和维持给定目标血液浓度所需的输注速率所涉及的微分方程太复杂，无法在手术室中手动执行。对于计算机来说，这些计算很容易执行，并且可以真实的实时计算任何目标血液浓度的输注方案。通过将计算机连接到可远程控制的输液泵，获得了一种系统，利用该系统，可以比利用蒸发器的吸入麻醉剂更容易地输送静脉内药物。这些系统被称为计算机控制的输注装置或靶控输注装置（TCI）。广崎是日本第一个参与评估这些新系统的中心。我们进行的另一项研究结果是芬太尼输注剂量方案，包括5- 15 μ g/kg，以获得3- 5 ng/ml的血药浓度。

With the help of pharmacokinetic principles it is possible to develop infusion schemes that rapidly obtain an predefined blood concentration of the infused drug and thereafter maintain this concentration. An example of such a scheme is the two-stage (2mg/kg, 2mg/kg/h)infusion regimen for ketamine intended to maintain the blood concentration at 1.0mug/ml. However, the requirement for anesthetic drugs varies from patient to patient and also for an individual patient according to the nature and intensity of the surgical stimulus. The differential equations involved in calculating the infusion rates needed to achieve and maintain a given target blood concentration are too complicated to perform by hand in the operating theater. For a computer these calculations are easy to perform and infusion schemes can be calculated for any target blood concentration in real time. By connecting a computer to a remotely controllable infusion pump a system is obtained with which intravenous drugs can be delivered with greater ease than inhalation anesthetics with a vaporizer. These systems are called computer controlled infusion devices or Target Controlled Infusion Devices (TCI) . Hirosaki was the first centers involved in the evaluation of these new systems in Japan. Another study results which we performed was a scheme of fentanyl infusion dose including 5-15mug/kg to get 3-5ng/ml blood concentration.