A Pharmacokinetics Simulator and Its Aplication to the Analysis of New Anesthetic; Sevoflurane

Abstract

We developed 9-compartments pharmacokinetics simulator using commercially available spread sheet software. The main features are type-less input of monitoring data in operating room and graphic plotting with X-Y plotter. We compared the measured values in sevoflurane's clinical phase study with predicted values from our simulator. Measured vs. predicted mean values from 5 volunteers were as following. About F_A/F_I at 1 hour after the start of anesthesia it was 0.88 vs, 0.86 and about the response time to verbal comands it was 10.7 vs. 11.1min. Both parameters correlated well.
From our simulations we predicted followings. F_A/F_I rise rapidly nealy like N₂O, but the brain concentration rise much slower than N₂O. The reason comes from the difference between alveolar and brain concentration introduced by the different λ Tissue/Gas of both anesthetics. Sevoflurane's vaporiser shoud not be setting on the level over 2.5 MAC for its safty and effective usage in clinical stage.