<unk> , also known as Ostwald<unk>  for<unk><unk><unk> , is a term used in pharmacology to describe the solubility of inhaled general anesthetics in<unk> . According to Henry's law, the ratio of the concentration in<unk>  to the concentration in<unk>  that is in contact with that<unk> , when the partial pressure in both compartments is equal, is nearly constant at sufficiently low concentrations. The<unk><unk>  is defined as this ratio and, therefore, has no units. The concentration of the anesthetic in<unk>  includes the portion that is undissolved in plasma and the portion that is dissolved (bound to plasma proteins). The more soluble the inhaled anesthetic is in<unk>  compared to in air, the more it binds to plasma proteins in the<unk>  and the higher the<unk> . It is inversely related to induction rate. Newer anesthetics (such as desflurane) typically have smaller<unk> s than older ones (such as ether); this leads to faster onset of anesthesia and faster emergence from anesthesia once application of the anesthetic is stopped, which may be preferable in certain clinical scenarios. If an anesthetic has a high<unk> , then a large amount of it will have to be taken up in the body's<unk>  before being passed on to the fatty (lipid) tissues of the brain where it can exert its effect. The potency of an anesthetic is associated with its lipid solubility, which is measured by its oil/gas<unk><unk> . Minimum alveolar concentration (MAC) is defined as the alveolar concentration of anesthetic<unk>  that prevents a movement response in half of subjects undergoing a painful (surgical) stimulus; simplified, it is the exhaled<unk>  concentration required to produce anaesthetic effects an inverse indicator of anesthetic<unk>  potency. __TOC__
Blood–gas partition coefficient
Oxygen enhancement ratio
Diffusing capacity
Minimum alveolar concentration
CO2 content
Biological half-life
Oxygenation index
Peak-to-trough ratio