[1]The Third Hospital of Qinhuangdao City;
Hebei;
066000;
[2]North China University of Science and Technology Affiliated Hospital;
063009;
[3]Orthopedics Hospital of Qinhuangdao City;
Hebei;
066000;
[1]The Third Hospital of Qinhuangdao City;
Hebei;
066000;
COPD; Acute exacerbation; CHD; ET-1; IL-8;