minimum alveolar concentration , MAC (Abkürzung)

It is a potent anesthetic with a minimum alveolar concentration of 0.74.

Further research into the possible mechanisms of narcosis by anesthetic action led to the "minimum alveolar concentration" concept in 1965.

Volatile agents are frequently compared in terms of potency, which is inversely proportional to the minimum alveolar concentration.

With a minimum alveolar concentration (MAC) of 0.2%, methoxyflurane is an extremely potent anesthetic agent.

However, the minimum alveolar concentration (MAC) for nitrogen is not achieved until pressures of about 20 to 30 atm (bar) are attained.

Cyclopropane is a relatively potent, non-irritating and sweet smelling agent with a minimum alveolar concentration of 17.5% and a blood/gas partition coefficient of 0.55.

In fact, newer volatile agents (e.g., sevoflurane, desflurane) have been popular not due to their potency (minimum alveolar concentration), but due to their versatility for a faster emergence from anesthesia, thanks to their lower blood-gas partition coefficient.

(Note: "MAC hour" is the multiple of the minimum alveolar concentration (MAC) of the anesthetic used times the number of hours the drug is administered, a measure of the dosage of inhaled anesthetics.)

The authors showed that subclinical nephrotoxicity occurred following methoxyflurane at minimum alveolar concentration (MAC) for 2.5 to 3 hours (2.5 to 3 MAC hours), while overt toxicity was present in all patients at dosages greater than five MAC hours.

Minimum alveolar concentration or MAC is a concept used to compare the strengths, or potency, of anaesthetic vapours; in simple terms, it is defined as the concentration of the vapour in the lungs that is needed to prevent movement (motor response) in 50% of subjects in response to surgical (pain) stimulus.