Bailey J M
Division of Cardiothoracic Anesthesia, Emory University School of Medicine, Atlanta, Georgia 30322.
J Pharmacokinet Biopharm. 1991 Dec;19(6):635-45. doi: 10.1007/BF01080871.
To rapidly achieve and maintain constant plasma concentrations most intravenous drugs must be administered as an initial bolus followed by a combination of exponentially declining plus constant-rate infusions. In the clinical practice of anesthesia and critical care medicine this is often not practical without specialized equipment. In this paper a simpler approach of maintaining approximately constant plasma concentrations is developed using a loading dose with a two-stage infusion scheme (an initial rapid infusion reduced at a given time to a lower rate). Equations are developed for determining the rate of the infusions as well as the duration of the initial infusion by equating moments of the Laplace transform of the approximate infusion to the moments of the Laplace transform of an exact solution. This approach is independent of models and uses as parameters the moments of the curve relating the concentration following a single iv dose of unit magnitude as a function of time. The accuracy of this technique was assessed by computer simulation.
为了迅速达到并维持恒定的血浆浓度，大多数静脉注射药物必须先给予一次初始推注，随后进行指数衰减加恒速输注的联合给药方式。在麻醉和重症医学的临床实践中，如果没有专门的设备，这种方法往往不实用。本文提出了一种更简单的维持近似恒定血浆浓度的方法，即采用负荷剂量和两阶段输注方案（初始快速输注，在给定时间后降至较低速率）。通过使近似输注的拉普拉斯变换的矩与精确解的拉普拉斯变换的矩相等，推导出了确定输注速率以及初始输注持续时间的方程。这种方法独立于模型，并将单次静脉注射单位剂量后浓度随时间变化曲线的矩作为参数。通过计算机模拟评估了该技术的准确性。
