Asthma: Overview and Management

Definition

• Chronic Inflammatory Disease: Affects the respiratory system.
• Key Characteristics:
  • Bronchial hyper-responsiveness
  • Episodic acute asthma exacerbations
  • Reversible airflow obstruction

Symptoms

• Shortness of breath
• Cough
• Wheezing
• Commonly presents in childhood
• Associated with conditions such as eczema and hay fever

Etiology

• Complex Pathology: Multifactorial influenced by genetics and environmental exposure.
• Triggers:
  • Irritants (e.g., cold air)
  • Allergens (e.g., pollen)

Pathological Processes

• Airflow Obstruction caused by:
  1. Inflammatory cell infiltration
  2. Mucous hypersecretion (mucous plug formation)
  3. Smooth muscle contraction
• Chronic Changes:
  • Basement membrane thickening
  • Collagen deposition
  • Fibrosis
  • Airway remodeling: smooth muscle hypertrophy and hyperplasia
  • Presence of specialized immune cells in chronic asthma

Triggers

• Avoidable Triggers:
  • Cigarette smoking
  • Allergens (animal, mold, pollen)
  • Environmental irritants (cold, perfumes, renovation materials)
  • Medications (aspirin, NSAIDs, beta-blockers)
  • Dietary triggers (food chemicals and additives)
• Unavoidable Triggers:
  • Respiratory tract infections
  • Exercise

Diagnosis

• Children: Based on history, examination, and clinical improvement with bronchodilators.
• Older Children/Adults: Pulmonary tests show reversibility in airflow obstruction after bronchodilator use.

Treatment

Assessment of Severity

1. Stepwise Approach:
   • Relievers:
     • Salbutamol (short-acting beta adrenergic agonist)
     • Anti-muscarinic inhalers
   • Preventers:
     • Corticosteroid inhalers
   • Combination Treatments:
     • If poorly controlled, consider montelukast and monoclonal antibodies (e.g., esinophil inhibitors)

Non-Pharmacological Management

• Importance of inhaler techniques
• Good adherence to treatment
• Create an action plan for exacerbations

Acute Asthma Episodes

• Types:
  • Mild
  • Moderate
  • Severe
  • Life-threatening
• Mild/Moderate Symptoms:
  • Able to speak in whole sentences
  • Oxygen saturation > 94%
• Severe Symptoms:
  • Dyspnea, use of accessory muscles
  • Unable to complete sentences
  • Oxygen saturation 90-94%
• Life-threatening Symptoms:
  • Reduced consciousness, exhaustion
  • Cyanosis, hypoxia < 90%
  • Soft or absent breath sounds

Treatment of Acute Asthma

• Mild to Moderate:
  • Bronchodilators (beta-2 agonists) and anti-muscarinic via nebulizer or inhaler
• Severe:
  • Add corticosteroids (oral or IV)
• Life-threatening:
  • Add magnesium sulfate, aminophylline, adrenaline
  • Consider non-invasive ventilation or intubation if necessary

Summary

• Asthma is a chronic inflammatory disease of the lungs characterized by shortness of breath, cough, and wheeze.
• It is a reversible lung disease with first-line treatment being bronchodilators.