What is the definition of a Chronic Obstructive Pulmonary Disease (COPD) exacerbation in an older adult with a history of smoking?

Definition of COPD Exacerbation

A COPD exacerbation is an acute worsening of respiratory symptoms that results in additional therapy. 1

Core Clinical Definition

The GOLD guidelines provide the most widely accepted definition: an exacerbation represents an acute event characterized by worsening respiratory symptoms beyond normal day-to-day variations that necessitates a change in medication. 1 The European Respiratory Society/American Thoracic Society further specifies this as episodes of increasing respiratory symptoms, particularly dyspnea, cough, sputum production, and increased sputum purulence. 1

Cardinal Symptoms

The key symptom of a COPD exacerbation is increased dyspnea. 1, 2 Additional symptoms that define an exacerbation include:

• Increased sputum volume 1, 2
• Increased sputum purulence 1, 2
• Increased cough and wheeze 1, 2
• Blood-streaked sputum may occur during exacerbations 2

Pathophysiologic Features

Exacerbations are complex events associated with:

• Increased airway inflammation 1
• Increased mucus production 1
• Marked gas trapping 1

These events are triggered predominantly by respiratory tract infections (viruses and bacteria), which are the most common precipitating factors. 1

Severity Classification

COPD exacerbations are classified into three severity categories based on treatment requirements: 1, 3

• Mild: Treated with short-acting bronchodilators only 1, 3
• Moderate: Treated with short-acting bronchodilators plus antibiotics and/or oral corticosteroids 1, 3
• Severe: Patient requires hospitalization or emergency room visit, may be associated with acute respiratory failure 1, 4

Critical Differential Diagnoses

A common pitfall is assuming all acute respiratory worsening in COPD patients represents an exacerbation. 2 Exacerbations must be differentiated from:

• Acute coronary syndrome 1, 2
• Worsening congestive heart failure 1, 2
• Pulmonary embolism 1, 2
• Pneumonia 1, 2
• Pneumothorax (particularly in bullous emphysema) 2

Clinical Impact

Exacerbations are important events because they:

• Negatively impact health status 1
• Increase rates of hospitalization and readmission 1
• Accelerate disease progression 1
• Can result in death 1

A significant proportion of exacerbations go unreported and untreated, leading to poorer prognosis than treated exacerbations. 5