COPD is a heterogeneous condition caused by airway (bronchitis/bronchiolitis) or alveolar (emphysema) abnormality, changes with chronic respiratory changes (dyspnea, dyspnoea, phlegm). It is characterized by persistent and frequently progressive airway obstruction. In COPD, which progresses with high mortality, non-pharmacological treatments are applied, as well as pharmacological treatments. They have an essential place in slowing down the progressive course of this treatment. However, despite the treatment administered to COPD patients, outdoor weather conditions, improper use of inhaler treatments, or comorbidities may cause acute exacerbation of COPD.

Dry air nebulizer devices use dry air from the central system in hospitals. This system, which converts bronchodilator drugs into nebulizers by creating high currents, works like classical nebulizers without an electrical system and can have a higher flow rate than jet nebulizer devices. This procedure, which can be applied to COPD patients without giving high-flow oxygen, prevents carbon dioxide retention. There is no study in the literature comparing the bronchodilator effectiveness of dry air, classical nebulizer, and jet nebulizer, and the investigators aimed to compare the efficacy of these three treatment modalities in our study.

Inclusion Criteria:

• Group E COPD patients

Exclusion Criteria:

• Recent MI
• Pulmonary embolism
• Cerebral aneurysm
• Active hemoptysis
• Pneumothorax
• Nausea, vomiting
• Recent thorax, abdominal, and eye surgery were identified in the patients before the pulmonary function test and were not included in the study.
• Mental retardation
• Pneumonia with acute exacerbation of COPD
• Patients with pulmonary edema due to congestive heart failure
• Patients with interstitial lung disease along with COPD