this study aims to investigative the benefits of using nebulized nitroglycerin in improving respiratory functions in patients of late stage COPD

the inhaled nitroglycerin is expected to make vasodilatation of the pulmonary arteries and arterioles which are constricted in late stages of COBD leading to ventilation/perfusion mismatching and further aggravating COPD. it will also help in delivering better antibiotic concentrations to the alveoli which help in better control of infection.

Inclusion Criteria:

• Adult patient's ≥ 18 years old COPD exacerbation with respiratory failure and Echo evidenced presence of pulmonary hypertension (defined as mean pulmonary artery pressure > 20 mmHg)

Exclusion Criteria:

• Profound left ventricular failure, as the decrease in pulmonary vascular resistance results in an increase in left ventricular preload. This may worsen cardiogenic pulmonary edema.
• Pregnant female patients
• Patient with hypersensitivity to nitroglycerin