 This prospective study intends to investigate the incidence of postoperative pulmonary complications PPC or in-hospital mortality in patients with COPD or at risk for COPD undergoing high-risk noncardiac major surgery and to identify relevant risk factors. Furthermore, this study aims to quantify and compare the diagnostic performance of preoperative functional tests, exercise capacity, clinical assessment tests and predictive scoring systems to predict PPC or in-hospital mortality in these patients. 