Chronic obstructive lung disease (COPD) is a major cause of morbidity and mortality, and is a major reason for ICU admission. Cardiac function is often impaired in this disease but its association with clinical outcome has not been fully established. The study aims to investigate the association between cardiac dysfunction and clinclial outcomes.

This is a prospective observational study conducted in a 47-bed mixed ICU of tertiary academic teaching hospital. The study will be performed between January 2014 to December 2015. All patients meeting the diagnostic criteria of AECOPD and admitted to ICU are potentially eligible for the present study. Relevant demographics and laboratory measurements are obtained. Transthoracic echocardiography (TTE) is performed immediately after ICU admission by experienced intensivists. Cox proportional hazard regression model is fitted by using stepwise forward selection and backward elimination technique. If linear assumption is not satisfied, the linear spline function will be used.

Inclusion Criteria:

• COPD patients experiencing episode of exacerbation and require mechanical ventilation were admitted to ICU

Exclusion Criteria:

• COPD patients admitted to ICU due to other reasons (major surgery, ischemic heart disease, and renal failure)
• moribund and expected to die within 48 hours
• with Do-Not-Resuscitation order

All patients meeting the diagnostic criteria of AECOPD and admitted to ICU are potentially eligible for the present study. The diagnosis of AECOPD is based on that defined in Global Initiative for Chronic Obstructive Pulmonary Disease. AECOPD is defined using definitive criteria with at least two of the following major symptoms: increased dyspnea, increased sputum purulence, increased sputum volume; or one major and one minor symptom: nasal discharge/congestion, wheeze, sore throat and cough for at least two consecutive days.