Chronic Obstructive Pulmonary Disease (COPD) Overview

Respiratory Medicine

• Focus is on chronic obstructive pulmonary disease (COPD)
• COPD is an obstructive airway disease
• COPD is a condition characterized by persistent airflow limitation not fully reversible

Chronic Obstructive Pulmonary Disease (COPD)

• Key characteristic is airflow limitation
• COPD is usually associated with abnormal lung inflammation
• COPD is a common, preventable, and treatable condition
• COPD is linked to persistent respiratory symptoms

Lecture Contents

• Includes a case scenario, epidemiology, types of COPD, causes and risk factors, pathophysiology, clinical features, diagnosis, management and prevention

Case Scenario

• A 66-year-old male smoker with a 47-year history of smoking.
• Exhibits progressive shortness of breath and a chronic cough producing yellowish sputum over the past 2 years.
• On examination, the patient appears cachectic with moderate respiratory distress, especially after walking, showing pursed-lip breathing and mildly distended neck veins.

Epidemiology of COPD

• Older adults, aged 65 and above, are more likely to develop COPD.
• Prevalence is highest in the WHO regions of the Americas
• Prevalence is lowest in South-East Asia and the Western Pacific
• COPD-related deaths globally increased 23% between 1990 and 2017 with about 3 million deaths annually.
• The expansion of smoking and aging populations, along with reduced mortality from other causes, suggest around 5.4 million annual COPD-related deaths by 2060.
• Global prevalence estimated at 11.7% (95% CI 8.4%–15.0%)

Types of COPD

• Emphysema (Pink puffer): characterized by terminal airway destruction and dilation resulting in thin, wasted appearance, pursed lips and minimal cough.
• Chronic bronchitis (Blue bloater): characterized by productive cough (lasting > 3 months for 2 consecutive years), overweight/edema, and early hypercarbia/hypoxia.

Causes and Risk Factors of COPD

• Tobacco smoking: A major cause, accounting for nearly 80% of cases.
• Environmental factors: Indoor and outdoor pollution, exposure to chemical fumes, inhaled dust/fumes and biomass fuels are risk factors.
• Genetic factors: Alpha-1-antitrypsin (alpha-1-antiprotease) deficiency is a significant genetic predisposition. Other COPD-related genetic markers may be identified.

Pathophysiology of COPD

• Characterized by an imbalance of oxidants and antioxidants
• Cigarette smoking and other inhalants exacerbate this imbalance
• The imbalance leads to inflammation, mucus hypersecretion, and destruction of alveoli, ultimately resulting in airflow obstruction
• The decline in the functionality of air sacs within the lung is a significant contributing factor

Clinical Features of COPD

• Symptoms include shortness of breath, chronic cough, sputum production, wheezing, and chest tightness.
• Patients with COPD often present with a lack of energy, inability to tolerate activities, nutritional deficits, and problems with gas exchange (respiratory acidosis).

Diagnosis of COPD

• Diagnosis relies on a spirometry test that demonstrates airflow obstruction (FEV1/FVC < 0.70).

Investigations for COPD

• CBC: Complete blood count
• Chest X-ray (CXR): Frequently normal, but can help rule out other conditions
• Spirometry: Essential test to confirm diagnosis of airflow obstruction (FEV1/FVC < 0.70)
• HRCT: High-resolution computed tomography. Useful to detect structural abnormalities
• ABGs: Arterial blood gases. Assessment of oxygenation and carbon dioxide levels in the blood
• ECG: Electrocardiogram – assess for issues related to the heart
• Echo: Echocardiography - evaluation for right heart stress that frequently accompanies COPD
• Alpha Anti-trypsin level: Important for assessing genetic risk factors

Considerations for COPD Diagnosis

• Patients symptomatic but lack overt symptoms may still need spirometry.
• Consider COPD if patients exhibit progressive dyspnea, persistent/recurrent cough, chronic sputum production, recurrent wheezing, recurrent respiratory infections, history of risk factors (smoking), or family history.

Severity Classification

• Severity classification using GOLD guidelines (Global Initiative for Chronic Obstructive Lung Disease) based on FEV1 predicted percentage. (Mild, Moderate, Severe, Very Severe)
• Grading of COPD severity by using a modified Medical Research Council (mMRC) scale.
• Patients graded 0-4 according to breathlessness severity
• CAT score: 0-40 that assesses symptom severity in COPD.
• Spirometry results/grading as additional support for assessment.

Management of COPD

• Pharmacological: Includes bronchodilators (e.g. LABA, LAMA, ICS, etc.), triple therapy. Pharmacological strategies for exacerbations should also be incorporated.
• Non-pharmacological: Includes smoking cessation, immunization (e.g. pneumococcal), pulmonary rehabilitation, oxygen therapy

COPD Assessment Tool (ABE)

• An updated tool used for classifying COPD patients based on symptom and exacerbation history. Used for treatment prioritization.

COPD Comorbidities

• COPD is frequently accompanied by other health problems, especially cardiovascular disease, obstructive sleep apnea, periodontitis, metabolic syndrome and diabetes.

Differentiating COPD from other conditions

• Differentiating COPD (e.g., asthma) requires consideration of symptoms, spirometry results, and additional diagnostic tests.

Non-pharmacological therapy for stable COPD

• Smoking cessation
• Immunization (pneumonia)
• Pulmonary rehabilitation, Oxygen therapy and Non-invasive positive pressure ventilation (NIV).

Oxygen therapy indications in COPD

• PaO2 / SaO2 levels below a certain threshold require oxygen therapy
• Exercise oxygen desaturation also warrants consideration, as may a history of right heart failure

COPD Exacerbation

• A COPD event where dyspnea and/or cough and sputum worsen over 14 days accompanied by tachypnea or tachycardia
• Causes include airway infection, pollution, or other airway irritants

Interventional and Surgical Therapy

• Includes surgical lung volume reduction, bullectomy and lung transplantation, when clinically warranted.

Interventions for COPD

• Interventions focused on reducing exacerbations and mortality include smoking cessation, pulmonary rehabilitation, vaccines, long-acting bronchodilators (including LABA and LAMA), antibiotics (macrolides) and mucolytics.

This quiz focuses on Chronic Obstructive Pulmonary Disease (COPD), a significant obstructive airway condition characterized by persistent airflow limitation and abnormal lung inflammation. It covers essential aspects including epidemiology, types, causes, clinical features, diagnosis, management, and prevention strategies. Engage with a case scenario to deepen your understanding of COPD symptoms and patient care.