median alveolar concentration

median alveolar concentration

The end-tidal concentration (in standardised pressure units) of inhaled anaesthetic that ablates movement (e.g., withdrawal) in response to surgical incision in 50% of a test population.

The original term, minimal alveolar concentration, referred to an end point that measured the concentration of inhaled anaesthetic required to block purposeful movement in an individual subject.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.