<unk>  or<unk>  is the<unk>  of a vapour in the alveoli of the lungs that is needed to prevent movement (motor response) in 50% of subjects in response to surgical (pain) stimulus.<unk>  is used to compare the strengths, or potency, of anaesthetic vapours. The concept of<unk>  was first introduced in 1965.<unk>  actually is a median value, not a<unk>  as term implies. The original paper proposed<unk>  as the minimal<unk><unk> , which was shortly thereafter revised to<unk> . A lower<unk>  value represents a more potent volatile anesthetic. Other uses of<unk>  include<unk> -BAR (1.7–2.0<unk> , which is the<unk>  required to block autonomic reflexes to nociceptive stimuli, and<unk> -awake (0.3–0.5<unk> , the<unk>  required to block voluntary reflexes and control perceptive awareness.
Minimum alveolar concentration
Effective dose 
Rate of infusion
Equivalent dose
Biological half-life
Absorbed dose
Peak-to-trough ratio
Dose area product