Inhalation anesthetic mechanism of action

Inhalation anesthetic mechanism of action after being administered and excreted via the lungs.

The dose of the agent is defined by the fraction of inhaled concentration that equates with the blood concentration and not the total amount of drug administered.

The minimum alveolar concentration (MAC) was introduced in 1963 as a comparison of potency of different inhalation agents as well as a guide for administration.

MAC is defined as the concentration of inhaled anaesthetic required to prevent movement in 50% of patients to surgical stimulus thus showing us inhalation anesthetic mechanism of action .

Inhalation anesthetic mechanism of action includes the alveolar concentration is approximated to the brain concentration and partial pressures are same in the brain and alveolus. Various factors affeët MAC, viz., ambient pressure (inversely proportional), age (decreases with age), temperature and ionic concentrations ofNa. MAC is maximum at 6 months of age-and reduces thereafter to 50% at 80 years of age @ 6% per decade. Hypernatraemia increases Na in CSF and increases MAC; conversely hyponatraemia reduces MAC.

Also the for the inhalation anesthetic mechanism of action , The structure and physical properties of presently available anaesthetic agents is so varied that a common mode of action is unlikely. However, there is a link between potency and lipid solubility as defined by the Meyer and Overton rule, indicating a molecular basis of anaesthetic action in cellular hydrophobic regions.

The rule postulates that it is the number of molecules dissolved at the site of action and not the type of molecules. There is expansion of hydrophobic regions, thereby obstructing channels on the cell membranes.

Though inhalation anesthetic mechanism of action is studied from other way, the interruption of transmission at the membrane of nerves may also be one of the theories, especially in the central nervous system involving membrane lipids, increased permeability, altered membrane dimension, protein binding and agent specific effect on 5H3-serotonin receptor function.

 

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