Anesthesia and the Meyer-Overton Rule II. A Solution Theory View of Anesthesia and Perturbations

Solution theory arguments play a significant role in the analysis of general anesthesia. However, the results are of limited value, due to the complexity of the systems to which these arguments are applied. This article suggests that we can advance our understanding of anesthesia by the analysis of a solution of hard spheres as an "ideal anesthetic medium". We obtain a precise definition of perturbation, which links together its structural and thermodynamical aspects in an accurate theory. It follows that this link applies to virtually all material systems, including the complex biological systems where anesthesia occurs. The derived relations: (i) explain the unique role of helium in hyperbaria; (ii) suggest how to establish a hierarchy of importance among possible causes of anesthesia; (iii) indicate the role of the Meyer-Overton rule in analyzing structural models of anesthesia; and (iv) depict the physical meaning of correlations, commonly used in anesthetic work, and show why they are more accurate than the Meyer-Overton rule.