目的　探讨机械通气治疗重症肌无力危象的指征、通气模式的选择及撤离机械通气的方法和指征。方法　分析 2 0例重症肌无力危象患者机械通气治疗前后血气指标 ,以及 1 2例患者机械通气初和撤离机械通气前床边呼吸功能检查。结果　 2 0例重症肌无力危象患者机械通气前后 3项血气指标有显著性差异 (P <0 0 5) ,其中 1 2例患者机械通气初和撤离机械通气前 2项呼吸功能检查有显著性差异 (P <0 0 5)。结论　呼吸衰竭是直接威胁重症肌无力危象患者生命的首要因素 ,及时气管切开行机械通气治疗 ,改善患者的通气功能是抢救成功的关键 ,积极控制肺部感染 ,消除诱因 ,使用大剂量糖皮质激素是患者早日撤离机械通气的保证。 Objective To investigate the indications of mechanical ventilation for the treatment of myasthenia gravis crisis, the choice of ventilation mode and the method of withdrawing mechanical ventilation. Methods Blood gas indexes before and after mechanical ventilation were analyzed in 20 patients with myasthenia gravis crisis and bedside respiratory function tests before mechanical ventilation and withdrawal mechanical ventilation in 12 patients. Results There were significant differences in the 3 blood gas indexes before and after mechanical ventilation among 20 patients with myasthenia gravis crisis (P <0.05), of which 12 patients had significant difference in the first two mechanical tests before mechanical ventilation and before mechanical ventilation Difference (P <0 05). Conclusions Respiratory failure is the primary factor that directly threatens the life of patients with myasthenia gravis crisis. Timely tracheostomy and mechanical ventilation are the keys to the success of resuscitation. Positive control of lung infection, elimination of the causes and the use of high-dose sugar Corticosteroids are the promise of early withdrawal of mechanical ventilation in patients.