[Validity of computer simulation in closed circuit anesthesia].

Developing a computer program to simulate the uptake, distribution, and elimination of inhalational anesthetics allow the anesthesiologist to address specific problems, but intense skills are required to translate the involved process first into a set of mathematical equations and then into a satisfactory computer program. The first step is facilitated by solutions offered in the literature. The second step by personal computer program now currently available as Gus, this program simulates anesthetic uptake and distribution using a numerical model with 12 compartments. Transport of anesthetic agents among the compartment occurs via convection of gas and blood during discrete iteration of the simulation. As initial clinical validation of the linear 12 compartment basic model the current study examined the predictive performance in 20 patients by comparing quantitatively the predicted and the measured alveolar concentration-time profiles after achievement of end tidal concentration of isoflurane (C-alv%) injected into a heated chamber (75 degrees) and then transported in closed circuit system during mechanical ventilation. With regard to the use of isoflurane 20 patients were adequately anesthetized with only 88 ml of liquid isoflurane and that is the same in simulation achieved by computer.