The purpose of this study is to determine whether indacaterol maleate 300 micrograms (mcg) is effective in the acute treatment of COPD and in particular on reducing lung hyperinflation and dynamic volumes.

Enrolled patients: COPD of any disease severity in stable conditions. 48 hours of inhalatory drugs wash out.

Evaluation: Plethysmographic test, blood gas analysis, blood pressure, cardiac frequency and Borg scale evaluation in basal condition and after 60 minutes of indacaterol maleate 300 mcg inhalation.

Inclusion Criteria:

• Signature of consensus
• COPD diagnosis
• Age from 50 to 85 years old
• history of COPD at least of one year
• respiratory stable conditions at least of one month
• Any basal FEV1 expressed in % of predicted value
• FEV1/ Forced Vital Capacity (FVC) less than 70%
• Former or active smokers with at least a smoking history of 20 pack year

Exclusion Criteria:

• Pregnancy
• FEV1/FVC more than 70%
• Known deficit of alpha 1 antitrypsin
• Subjects submitted to a Lung Volume Reduction Surgery (LVRS)
• Subjects with known positivity to Human Immunodeficiency Virus (HIV)
• Misuse of alcool or drugs
• Absence of compliance in performing respiratory tests