Bronchial Asthma

Asthma is a heterogeneous disease, characterized by chronic airway inflammation. It is defined by h/o respiratory symptoms such as dry cough, SOB, chest tightness, a wheeze that vary over time & intensity, together with variable expiratory airway limitation, which may later become persistent.

In common language, asthma is associated with airway hyper-responsiveness and airway inflammation in response to an external allergen; which leads to airway narrowing & subsequently difficulty in breathing.

Epidemiology:

• As of 2004, it was estimated that as many as 300 million people of all ages suffer from asthma, by 2025, it is expected that this number will rise to 400 million worldwide (GINA).
• The Indian study on the epidemiology of asthma.
• Respiratory symptoms and chronic bronchitis (INSEARCH) in every adult, estimated the prevalence rate of asthma at 2.05% between 2007 and 2009, with an estimated burden of about 17.23 million in 2011.
• Agarwal etal. estimated the prevalence rate of self-reported asthma at around 2%.

Asthma phenotypes: Recognizable cluster of demographic, clinical, and/or pathophysiological characteristics are k/an asthma phenotype.

• Allergic asthma
• Non-allergic asthma
• Adult-onset (late-onset) asthma
• Asthma with persistent airflow limitation
• Asthma with obesity

Triggering factors:

• Respiratory infection (viral)
• Allergen or irritant exposure
• Cold weather
• Exercise
• Smoke/dust/fumes
• Medication such as B-blocker (beta-blocker) and aspirin
• Pollen
• Mites
• Mould & fungus
• Air pollutants (NO₂, SO₂, O3)
• Emotional stress

Diagnosis of Bronchial Asthma:

• History of variable respiratory symptoms:
• Wheeze
• SOB (shortness of breath)
• Chest tightness
• Cough

Pulmonary function test with bronchodilator reversibility:

• Document variable expiratory airflow limitation.
• At a time when fevi is reduced, confirm that fevi/fvc is also reduced.
• Positive BDR: increase in FEV, >12% and >200 ml from baseline.

Management:

1. Non-pharmacological:

• Cersation of smoking & ETS (Environmental Tobacco smoke exposure)
• Encourage regular physical activity for general health benefits
• Avoid medication (NSAIDs; beta-blocker)
• Weight reduction/healthy diet
• Encourage breathing exercises
• Avoid outdoor allergen (like pollen/dust)
• Deal with emotional stress (anxiety/depression)
• Psychological counseling.

2. Pharmacological:

• Inhaled coticosteroid
• Inhaled long-acting beta-agonist
• Leukotriene modifiers

Add on therapy:

1. Tiotropium
2. Low dose Macrolide
3. Low dose oral corticosteroid
4. Anti IgE
5. Anti IL4 R
6. Anti IL5/5R
7. Bronchial Thermoplasty

Other Therapies:

1. Allergen Immunotherapy
2. Vaccination – Influenza & Pneumococcal Vaccine
3. Vitamin D Supplementation

Dr. Jagdish Lohia, Consultant – Pulmonology, Brahmananda Narayana Multispeciality Hospital, Jamshedpur