<prompt> Minimum alveolar concentration MAC denotes:EfficacyPotencySolubilityDiffusibility  <response>: Ans. B. PotencyExplanationMAC is an indicator of gas potency. The blood:gas partition coefficient is an indicator of solubility, which affects the rate of induction and emergence; it is NOT related to MAC.MAC: Alveolar concentration of a gas at which 50 of subjects do not respond to surgical incision.MAC of Inhaled Anesthetics GasBlood: Gas partition coefficient MACHalothane2.40.75 Enflurane1.91.7 Isoflurane1.41.2 Sevoflurane0.652.0 n2o0.47104 Desiflurane0.426.0 MAC values for adults 36--49 years old.Important points:Remarkably consistent across species.MAC is a population average; not a true predictor of an individuals response.MAC is an ED50 concentration. The ED95 is - 25, so at 1.3 MAC, 95 of patients will not respond to incision.MAC values are additive e.g. 0.5 MAC isoflurane 0.5 MAC N20 1 MACMAC-A wake a.k.a. MAC-A ware: The MAC necessary to prevent response to verbaltactile stimulation. - Volatiles: 0.4 MAC; N20: -0.6 MACMAC-BAR: The MAC necessary to blunt the autonomic response to a noxious stimulus --1.6 MACMAC-intubation: The MAC necessary to prevent laryngeal response to endotracheal intubation --1.3 MAC 