Question

Describe the pathophysiology of COPD and explain how it can progress to lung hypertension, causing ventilation-perfusion mismatch

Answer 1

Chronic obstructive pulmonary disease

It is characterized by chronic obstruction of airflow (partial or complete). There is increased resistance to airflow from the trachea and large bronchi to the terminal and respiratory bronchioles due to increased luminal secretions ( cystic fibrosis or smoking), thickening of the airway wall (edema or hypertrophy), or loss of the elastic recoil of the airway (parenchymal destruction)

Patients show a marked decrease in the forced expiratory volume (FEV1) and an increased or normal forced vital capacity resulting in a decreased FEV1: FVC ratio.

This leads to pulmonary arterial vasoconstriction due to hypoxia. Persistent vasoconstriction gives rise to remodeling of pulmonary arteries and destruction of pulmonary bed and this ultimately leads to pulmonary hypertension. If it is not controlled then it can progress to Cor pulmonale and ultimately leads to death.