Multiple model approach to uptake and distribution of halothane: The use of an analog computer

Abstract

This paper describes a multiple analog computer model of the uptake and distribution of the anesthetic agent halothane. The model consists of two interdependent loops, one representing the blood circulation and another representing the halothane transport. Cardiac output and regional conductances are influenced in relation to the concentration of halothane in some relevant compartment of the model. Computer generated curves are given to show the response of alveolar concentration, arterial pressure and cerebral blood flow to step and pulse changes in inspired concentration. For evaluation of the model, other variables than alveolar concentration, such as, arterial pressure and blood flow may often be more useful. The present model will be used to develop an automatic control system for the administration of anesthesia.