Compare the Effects of Nebulizer Versus Inhaler Based Therapy for COPD Using Long-acting Bronchodilators

The purpose of this study is to compare the effectiveness of inhaled bronchodilators delivered via nebulizers vs. dry powder inhalers (DPIs) in symptomatic participants with Chronic Obstructive Pulmonary Disease (COPD) who have airflow obstruction (FEV1/FVC ≤ 70%) and show significant air trapping (RV ≥ 120% of predicted). The investigators hypothesize that, in patients with symptomatic COPD, therapy with a long-acting anti muscarinic agent/long-acting beta agonist (LAMA/LABA) combination administered by nebulizer will improve hyperinflation (increase in inspiratory capacity and reduction in residual volume) and reduce symptoms related to COPD to a greater extent than LAMA/LABA therapy given by a DPI. The study aims to demonstrate the following: 1. Compare the values of inspiratory capacity (IC) and residual volume (RV) in patients receiving LAMA/LABA by DPI with those receiving LAMA/LABA by nebulizer 2. Compare patient reported outcomes (COPD Assessment Test (CAT score), Baseline/Transition Dyspnea Index (BDI/TDI) and the St. George Respiratory Questionnaire (SGRQ) in symptomatic patients with COPD receiving LAMA/LABA by DPI with those receiving LAMA/LABA by nebulizer

Inclusion Criteria: 1. Age \> 40 years 2. Either sex 3. Current smoker or past cigarette smoking history of \> 10 pack-years 4. Symptoms of COPD (cough, sputum production, shortness of breath) 5. Modified Medical Research Council Dyspnea Scale (mMRC) score ≥2 or CAT score ≥10 at Screening/Run-in visit 6. A PIFR \> 30 at screening 7. FEV1/FVC ratio \< 70% (within the past 12 months) 8. Residual volume (RV) ≥ 120% predicted (within the past 12 months Exclusion Criteria: 1. Diagnosis of asthma (Verification via medical record and/or patient report) 2. Previously diagnosed atrial fibrillation with rapid ventricular response (heart rate \> 110 bpm) or ventricular arrhythmia (ventricular tachycardia) (Verification via medical record and/or patient report) 3. Acute myocardial infarction within 12 weeks of patient study registration (Verification via medical record and/or patient report) 4. Acute exacerbation of congestive heart failure (Verification via medical record and/or patient report) 5. Acute exacerbation of COPD within 8 weeks (Verification via medical record and/or patient report) 6. Recent (within 8 weeks) h/o eye surgery (Verification via medical record and/or patient report) 7. Uncontrolled glaucoma (Verification via medical record and/or patient report) 8. Known diagnosis of liver cirrhosis (Verification via medical record and/or patient report) 9. Known diagnosis of chronic renal insufficiency (defined as a previous serum creatinine \> 2.5 mg/dL - Verification via medical record and/or patient report) 10. Intolerance to any of the study drugs 11. Patients receiving long-term azithromycin 12. Planned surgery requiring hospital admission within 3 months 13. Currently enrolled in a pulmonary rehabilitation program 14. Inability to give informed consent 15. Pregnant or nursing women or women of childbearing potential not using a medically approved means of contraception (i.e., oral contraceptives, intrauterine devices, diaphragm, or subdermal implants) 16. Inability to understand instructions or comply with the study protocol 17. Participation in another investigational drug clinical trial within 30 days of patient study registration Medical history can be confirmed by medical records and/or verbal confirmation from patients. However, Inclusion criteria 6 \& 7 must be verified by a previous PFT report dated within 6 months of screening