 The study try to illustrate the possible mechanisms of tending to induce airway spasms and the impact of dexmedetomidine on inflammatory reaction in general anesthesia patients with asthma,by detecting the differences of plasma inflammatory factor interleukinIL-4, IL-5, IL-13, IL-17, IL-33, MBP and immunoglobulin EIgE levels between asthma patients and non-asthma patients. 