Anesthesia

Although scientists are not sure exactly how anesthesia works, there are many theories that have been proposed. In addition, different anesthetics may have different mechanisms of action. One theory proposes a relationship between the solubility of the anesthetic agent into the fat cells of the body (lipid solubility) as determining the degree of its potency as an anesthetic agent. Since nerve cell membranes are highly lipid, the brain, with its high nerve cell content, soaks up the anesthetic. Not all lipid soluble substances, however, are anesthetics. Lipid solubility, therefore, is only a partial explanation of the anesthetic's mechanism.

Another feature of anesthetic absorption is the way it is passed from the lungs to other cells in the body. At first there is a quick transmission from the lungs to the rest of the body, but as an equilibrium is reached, the anesthetic begins to quickly pass out from the lungs. However, fat cells retain the anesthetic longer than other cells.

Studies have shown that some inhaled anesthetics are metabolized by the liver (hepatic metabolism). Here is where the skill of the anesthetist is needed to control the amounts administered in order to avoid the problem of toxicity.