Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are associated with severe dyspnea and exercise intolerance. Early pulmonary rehabilitation (EPR) may lead to improvements in dyspnea and exercise tolerance, as it does in stable COPD patients.

One hundred and six patients admitted in a university hospital with AECOPD were randomized after discharge to either EPR for 8 weeks (EPR group) or usual care (UC) (UC group). All patients carried out the following initially and after 8 weeks: spirometry, 6minute walk test (SMWT), and a symptom-limited incremental cycle cardiopulmonary exercise test (CPET), and different dyspnea dimensions evaluation as following: Dyspnea intensity during incremental exercise using Borg scale, dyspnea 12 questionnaire and COPD assessment test (CAT) to assess sensory perceptual, affective distress, and symptom impact domains respectively.

Inclusion Criteria:

• Hospitalized COPD patients with a diagnosis of AECOPD with no clinically significant arterial hypoxemia at rest or on exercise (resting percutaneous oxygen saturation (SpO2) > 90% or a sustained decrease of < 4% during exercise) were recruited. Diagnosis of COPD, AECOPD and spirometric assessment of airflow limitation severity was based on Global Initiative for Chronic Obstructive Lung Disease (GOLD)

Exclusion Criteria:

• Patients with a prior diagnosis of other cardiorespiratory conditions (i.e., bronchial asthma, interstitial lung diseases, primary pulmonary hypertension, chronic congestive heart failure), as well as other conditions such as orthopedic, muscular and peripheral vascular diseases that could cause or contribute to breathlessness and exercise intolerance and/or could interfere with carrying out of exercise testing, were excluded.