Objective To evaluate the influence of early mobilization on delirium and respiratory dynamics in mechanically ventilated patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Methods The study prospectively recruited 107 AECOPD patients who admitted between January 2014 and June 2015 and underwent mechanical ventilation.On basis of same routine treatment,the patients were randomly divided into a treatment group (54 cases)receiving regime of early mobilization,and a control group (53 cases)receiving routine sedation and analgesia treatment.The incidence of delirium,duration of delirium,time of mechanical ventilation,and ICU mortality were compared between two groups.The respiratory mechanical parameters including endogenous positive end expiratory pressure (PEEPi),airway resistance(Raw),static compliance(Cs),and dynamic compliance(Cd)before treatment,3 days and 5 days after treatment were also compared between two groups. Results Compared with the control group,the incidence of delirium decreased (59.3% vs. 77.4%),the duration of delirium [(1.8±1.1)d vs. (2.6±1.3)d] and mechanical ventilation[(6.2±3.4)d vs. (7.9±4.2)d] reduced in the treatment group with significant difference(P<0.05).There was no significant difference in respiratory mechanical parameters before treatment between two groups(P>0.05).While at 3 days and 5 days after treatment,PEEPi decreased [(6.23±2.83)cm H2O vs. (7.42±2.62)cm H2O,(4.46±2.20)cm H2O vs. (5.92±2.51)cm H2O],Raw decreased [(20.35±7.15)cmH2O·L-1·s-1 vs. (23.23±6.64)cm H2O·L-1·s-1,(16.00±5.41)cm H2O·L-1·s-1 vs. (19.02±6.37)cm H2O·L-1·s-1],Cd increased [(25.20±9.37)mL/cm H2O vs (21.75±7.38)mL/cm H2O,(27.46±5.45)mL/cm H2O vs. (24.40±6.68)mL/cm H2O] in the treatment group compared with the control group(P<0.05),and the difference in Cs was not significant(P>0.05).No complications such as slippage,physical injury,or malignant arrhythmia occurred in two groups.The mortality slightly decreased in the treatment group compared with the control group (5.6% vs 11.3%),but the difference was not statistically significant(P>0.05). Conclusions The incidence of delirium is high in mechanically ventilated patients with AECOPD.Early mobilization can reduce the incidence and duration of delirium,decrease the airway resistance,increase the dynamic lung compliance,relieve dynamic pulmonary hyperinflation and reduce PEEPi,so as to improve the respiratory function and shorten the time of mechanical ventilation.Therefore,early mobilization is an effective and safe regime for AECOPD patients underwent mechanical ventilation.