COPD - UNFINISHED

COPD Definition

Chronic Obstructive Pulmonary Disease is a heterogenous lung condition characterised by chronic respiratory symptoms, due to abnormalities of the airways that cause persistent, often progressive, airflow obstruction

Pathobiology of COPD

Irreversible and chronic changes in the proximal and peripheral airways, alveoli and lung vasculature

Inflammatory of proximal airways

• enlarged submucosal glands

• Mucus hyper secretion

This adds to blockage of airways

Inflammation of peripheral airways

• airway wall thickening —> airway narrowing

• Increased inflammatory response

Lung Parenchyma/Alveoli inflammatory and structural changes

• alveolar wall destruction - reduces SA for gaseous exchange —> which creates ventilation-perfusion mismatch

Pulmonary vasculature inflammatory and structural changes

• thickening of artery walls and maybe loss of smaller vessels

• Leads to pulmonary hypertension

Pathophysiology - Effects of COPD

• Airflow Limitation

• Hyperinflation

• Pulmonary Gas Exchange abnormalities

• Pulmonary Hypertension

• Exacerbations

• Multimorbidity

Risk Factors for COPD

Environmental Factors

• Smoking + passive smoke

• Biomass exposure

• Air pollution

Host Factors

• Alpha-1 antitrypsin deficiency

• Association between birth weight and FEV1

Clinical Indicators for COPD Diagnosis

• Dyspnea that’s progressive overtime, worse with excercise and persistent

• Recurrent wheeze

• Chronic cough (may be intermittent and non-productive)

• Recurrent lower respiratory tract infections

• History of risk factors

Spirometry relevant to COPD

• FEV1 - Forced Expiratory Volume in 1 second

• FVC - Forced Vital Capacity (total among of air expired after a maximal inspiration)

• FEV1/FVC - ration between the 2 parameters

Initial Assessment of COPD

• Severity of AFO - Airflow Obstruction (mild, moderate, severe)

• Nature + magnitude of symptoms like breathlessness to rule out cardiac issues

• History of exacerbations

• Eosinophil count

• Multimorbidity

Measurement of severity of AFO

• Mild - FEV1 > 80%

• Moderate - FEV1 between 50-80%

• Severe - FEV1 between 30-50%

• Very Severe - FEV1 below 30%