Minimum alveolar concentration

The minimum alveolar concentration ( minimum alveolar concentration english, abbr: MAC) is a term used in anesthesiology and describes the anesthetic potency of inhalation anesthetics.

The commonly used MAC ( MAC50 ) is defined as the alveolar concentration of a Inhalationsnarkotikums at which 50 % of patients no longer respond to a skin incision ( " surgical MAC" ).

Unlike defined MACs are mac95 ( no pain response in 95 % of patients), the MAC EI ( no defensive movements of endotracheal intubation ), the MAC BAR ( block adrenergic response, no reaction of the sympathetic nervous system to noxious stimuli ) awake and MAC ( concentration at which 50 % of the patients go to the eyes)

It is expressed as a percentage of a gas mixture and varies depending on the oxygen admixture. In babies, young children, feverish and alcoholics the MAC is higher than for the average patient, while it is lower in pregnant women, in old age, in shock, anemia, low thyroid activity (hypothyroidism) and with concomitant use of certain drugs such as benzodiazepines or analgesics.