【Abstract】 Background The postoperative respiratory event is one of the most common complications in early surgery patients.Emergency reintubation in the post-anesthesia care unit (PACU) is needed for a ventilator support. Objective Effective prevention,timely detection and treatment can minimize the incidence and risk of hypoxemia. Content This study would research the factors associated with the occurrence of a respiratory event in the PACU:patient factors including elder,smoking and obesity,surgical factors including operative site and operative time,and specific aspects of anesthetic management. Trend The occurrence caused critical respiratory complications in the PACU may be the effect of one or more factors.This study will prompt further studies on preventative measures or evaluation of how to improve outcomer.