Makindo Medical Notes

Introduction

• Condition in which patients exhibit features of both asthma and chronic obstructive pulmonary disease (COPD).
• Persistent airflow limitation with features of airway hyperreactivity typical of asthma, combined with chronic airflow obstruction seen in COPD.
• Worse outcomes than either asthma or COPD alone and poses diagnostic and therapeutic challenges.

Pathophysiology

• Asthma Component: Involves chronic airway inflammation, eosinophilic infiltration, and reversible airway obstruction due to bronchoconstriction.
• COPD Component: Involves irreversible airway obstruction, neutrophilic inflammation, and progressive destruction of alveolar walls (emphysema) or chronic bronchitis.
• Overlap Features: features of both conditions, including airway hyperreactivity, persistent inflammation, and airflow obstruction that may be only partially reversible.

Risk Factors

• Smoking: Tobacco smoke is a risk factor for COPD> Smokers with asthma are at higher risk of developing ACOS.
• Age: ACOS is more common in older adults, especially with asthma or smoking.
• Occupational Exposure: Long-term exposure to dust, fumes, and chemicals can contribute
• Genetic Factors: Family history of asthma or COPD increases the risk.

Clinical Features are symptoms that overlap between asthma and COPD

• Dyspnoea: Chronic, progressive shortness of breath, worsened by exertion.
• Chronic Cough: Persistent cough, often with sputum production (more typical of COPD).
• Wheezing: Episodic wheezing, especially during exacerbations or with allergen exposure.
• Frequent Exacerbations: More frequent respiratory exacerbations compared to patients with asthma or COPD alone.
• Airflow Limitation: Persistent airflow limitation on spirometry, with only partial reversibility following bronchodilator administration.
• Nocturnal Symptoms: May experience nighttime cough and shortness of breath (more typical of asthma).
• History of both chronic bronchitis or emphysema (COPD) and asthma-like symptoms (e.g., wheezing, allergy history).
• Physical exam may reveal wheezing, prolonged expiratory phase, or hyperinflation of the chest.

Investigations

• Spirometry:
  • Reduced FEV1/FVC Ratio: Persistent airflow limitation (FEV1/FVC < 0.7) is common in ACOS.
  • Partial Reversibility: A post-bronchodilator increase in FEV1 by ≥12% and 200 mL, but with incomplete normalization of lung function.
• Biomarkers
  • Peripheral Eosinophilia: May indicate asthma-like inflammation in ACOS patients.
  • Exhaled Nitric Oxide (FeNO): Elevated FeNO levels suggest an asthmatic component in airway inflammation.
• Imaging
  • Chest X-ray: May show hyperinflation or increased bronchial markings consistent with COPD.
  • CT Scan: High-resolution CT can reveal emphysema, bronchial wall thickening, or other structural changes.

Pharmacological Management

• Inhaled Corticosteroids (ICS): First-line treatment for asthma components. Reduces airway inflammation and decreases exacerbations.
• Long-Acting Beta-Agonists (LABAs): Used in combination with ICS for bronchodilation and symptom control.
• Long-Acting Muscarinic Antagonists (LAMAs): Effective in reducing airflow obstruction and preventing exacerbations in the COPD component.
• Short-Acting Bronchodilators: Used as rescue therapy during exacerbations or for acute symptoms (e.g., short-acting beta-agonists like salbutamol).
• Oral Corticosteroids: May be required during severe exacerbations but should be used cautiously due to side effects.
• Leukotriene Receptor Antagonists (LTRAs): May be considered for patients with prominent allergic or asthmatic features.

Non-Pharmacological Management

• Smoking Cessation: is critical in managing COPD and preventing further lung damage in ACOS.
• Pulmonary Rehabilitation: Exercise and education helps exercise capacity and quality of life.
• Vaccinations: Annual influenza vaccination and pneumococcal vaccination are recommended.
• Self-Management Education: Teach patients how to recognize exacerbation symptoms and use rescue medications effectively.

Exacerbation Management

• Inhaled Bronchodilators: Short-acting bronchodilators (e.g., salbutamol, ipratropium) for rapid symptom relief.
• Systemic Corticosteroids: Oral prednisone or IV hydrocortisone to reduce inflammation during acute exacerbations.
• Antibiotics: Considered in cases of bacterial infection, particularly if sputum changes (e.g., purulence, increased volume) or fever are present.
• Oxygen Therapy: Administered if hypoxemia is present (SpO2 < 90%), but used cautiously to avoid CO2 retention in COPD patients.

Prognosis

Patients with ACOS tend to have a worse prognosis than those with either asthma or COPD alone. They experience more frequent exacerbations, higher rates of hospitalizations, and more rapid lung function decline. However, with appropriate management, symptom control and quality of life can be improved.