What is the comprehensive approach to understanding and managing bronchial asthma?

Understanding and Managing Bronchial Asthma: A Comprehensive Guide

Bronchial asthma requires a stepwise approach to management with inhaled corticosteroids as the cornerstone of therapy for persistent asthma, supplemented by bronchodilators and other medications based on symptom severity and control. 1, 2

Definition and Pathophysiology

Asthma is a chronic inflammatory disorder of the airways characterized by:

• Variable and recurring symptoms
• Airflow obstruction
• Bronchial hyperresponsiveness
• Underlying inflammation 1

The pathophysiological features include:

• Inflammatory cell infiltration (mast cells, eosinophils, T lymphocytes, macrophages)
• Airway edema
• Mucus hypersecretion
• Smooth muscle hypertrophy
• Airway remodeling with subepithelial fibrosis 1, 3

These changes lead to:

• Bronchoconstriction
• Airway hyperresponsiveness
• Progressive airflow limitation 1

Clinical Presentation

Key symptoms include:

• Wheezing
• Coughing (particularly at night or early morning)
• Chest tightness
• Shortness of breath
• Sleep disturbance due to symptoms 1

Diagnosis

Diagnosis is based on:

1. Symptom pattern and history

   • Recurrent episodes of respiratory symptoms
   • Symptoms worse at night/early morning
   • Triggers identified (allergens, exercise, cold air)

2. Lung function testing

   • Spirometry showing obstruction (reduced FEV1)
   • Reversibility testing (≥12% improvement in FEV1 after bronchodilator)
   • Peak expiratory flow (PEF) monitoring showing variability

3. Additional tests when needed

   • Bronchial challenge testing
   • Allergy testing
   • Exhaled nitric oxide measurement 1

Assessment of Severity and Control

Assessment should focus on two domains:

• Impairment: Frequency and intensity of symptoms, functional limitations
• Risk: Likelihood of exacerbations, decline in lung function, medication side effects 1

Control assessment includes:

• Daytime symptoms (frequency)
• Nighttime awakenings
• Need for rescue medication
• Activity limitation
• Lung function measurements
• Exacerbation frequency 2

Management Approach

1. Education and Partnership

• Develop written asthma action plan
• Teach recognition of worsening symptoms
• Instruct on proper medication use
• Demonstrate inhaler technique 1, 2

2. Environmental Control

• Identify and reduce exposure to allergens and irritants
• Address occupational exposures
• Avoid tobacco smoke exposure 1

3. Pharmacologic Therapy (Stepwise Approach)

Step 1: Intermittent Asthma

• Short-acting beta-agonists (SABA) as needed

Step 2: Mild Persistent Asthma

• Low-dose inhaled corticosteroid (ICS) daily
• Alternative: Leukotriene modifier or cromolyn

Step 3: Moderate Persistent Asthma

• Low-dose ICS plus long-acting beta-agonist (LABA)
• Alternative: Medium-dose ICS

Step 4: Severe Persistent Asthma

• Medium-dose ICS plus LABA
• Consider adding tiotropium

Step 5: Very Severe Persistent Asthma

• High-dose ICS plus LABA
• Consider omalizumab for allergic asthma

Step 6: Most Severe Asthma

• High-dose ICS plus LABA plus oral corticosteroids
• Consider biologics based on phenotype 1, 2

4. Regular Monitoring and Follow-up

• Assess control at every visit
• Adjust therapy (step up if needed, step down if possible)
• Review inhaler technique
• Monitor for medication side effects 1

Management of Exacerbations

For acute exacerbations:

1. Assessment of severity:

   • Ability to speak in sentences
   • Respiratory rate (>25/min indicates severe)
   • Heart rate (>110/min indicates severe)
   • Oxygen saturation (<92% indicates severe)
   • Peak flow (<50% predicted indicates severe) 2

2. Immediate treatment:

   • Oxygen (40-60%)
   • Nebulized salbutamol 5-10 mg or terbutaline 5 mg
   • Systemic corticosteroids (prednisolone 30-60 mg)
   • Consider adding ipratropium bromide 0.5 mg nebulized 1

3. Monitoring response:

   • Repeat PEF measurement 15-30 minutes after starting treatment
   • Monitor oxygen saturation
   • Assess symptoms and vital signs 1

4. Discharge considerations:

   • PEF >75% of predicted or personal best
   • Symptoms controlled
   • Discharge medications (including oral corticosteroids)
   • Follow-up appointment arranged
   • Asthma action plan reviewed 1

Special Considerations

Pregnancy

• Maintain asthma control during pregnancy
• Most asthma medications are safe during pregnancy
• Uncontrolled asthma poses greater risk than medications 1

Exercise-Induced Bronchoconstriction

• Pre-treatment with SABA 15 minutes before exercise
• Regular controller therapy for those with persistent symptoms
• Warm-up before exercise 1

Surgery

• Maintain asthma medications during perioperative period
• Consider stress-dose steroids for patients on high-dose ICS 1

Common Pitfalls to Avoid

1. Overreliance on rescue medications - If using more than one SABA inhaler per month, controller therapy should be increased 2

2. Underuse of inhaled corticosteroids - ICS are the foundation of persistent asthma management 1, 2

3. Poor inhaler technique - Regularly assess and correct technique

4. Failure to address comorbidities - GERD, rhinosinusitis, obesity, and sleep apnea can worsen asthma control 1

5. Misdiagnosis - Conditions like vocal cord dysfunction can mimic asthma 1

6. Inadequate follow-up - Regular monitoring is essential for optimal control

By following this comprehensive approach to asthma management, most patients can achieve good symptom control and minimize the risk of exacerbations.