AIM STEP 7
3rd Year MBBS
Respiration
3rd Year MBBS
Respiration
Student Memory Support
Topic 8 — Bronchial Asthma and Its Pharmacotherapy
High-yield memory reinforcement for rapid KMU examination revision.
1. High-Yield Flashcards
Tap each question to reveal the answer.
What are the three central physiological features of bronchial asthma?
Chronic airway inflammation, bronchial hyperresponsiveness and variable airflow obstruction.
Which inflammatory cells are especially important in allergic asthma?
Mast cells, type 2 helper T cells and eosinophils.
Which cytokine is strongly associated with eosinophil recruitment in allergic asthma?
IL-5.
What three processes acutely narrow the airway during an asthma attack?
Bronchial smooth-muscle contraction, mucosal edema and increased mucus.
What important structural changes occur in airway remodeling?
Subepithelial fibrosis, smooth-muscle hypertrophy, goblet-cell hyperplasia and mucus-gland enlargement.
What spirometric feature strongly supports a diagnosis of asthma?
Variable or reversible expiratory airflow limitation.
Why can normal spirometry between attacks fail to exclude asthma?
Because airway obstruction in asthma varies over time and may normalize between episodes.
How do beta-2 agonists produce bronchodilation?
Beta-2 receptor stimulation increases cyclic AMP, relaxing bronchial smooth muscle.
What is the main therapeutic role of inhaled corticosteroids in asthma?
Suppression of chronic airway inflammation for long-term disease control.
Which important local adverse effects may follow inhaled corticosteroid use?
Oral candidiasis and dysphonia.
How does ipratropium help relieve bronchospasm?
It blocks muscarinic receptors and reduces cholinergic bronchoconstriction.
Why is theophylline toxicity clinically important?
It has a narrow therapeutic index; severe toxicity can cause arrhythmias and seizures.
What is the main pharmacological action of montelukast?
It blocks leukotriene receptors, reducing leukotriene-mediated bronchoconstriction and mucus production.
What is the therapeutic target of omalizumab?
Circulating IgE.
What historical pattern should raise suspicion of occupational asthma?
Symptoms worsen during workplace exposure and improve during periods away from work.
2. Mnemonics
Mnemonic Title: Main Causes of Airway Narrowing
BEM
BEM
Meaning: Bronchoconstriction, Edema, Mucus.
Mnemonic Title: Major Asthma Symptoms
WCBC
WCBC
Meaning: Wheeze, Cough, Breathlessness, Chest tightness.
Mnemonic Title: Check Before Stepping Up Therapy
DATE
DATE
Meaning: Diagnosis, Adherence, Technique, Exposure to triggers.
3. Memory Tables
Atopic vs Non-Atopic Asthma
| Feature | Atopic | Non-Atopic |
|---|---|---|
| Main association | Allergic sensitization | No dominant allergen sensitization |
| IgE | Prominent | Less prominent |
| Typical triggers | Allergens | Infections, irritants, cold air |
Major Asthma Drug Groups
| Drug/Class | Main Action | Memory Point |
|---|---|---|
| Beta-2 agonist | Bronchodilation | ↑ cyclic AMP |
| Corticosteroid | Suppress inflammation | Core controller |
| Antimuscarinic | Blocks cholinergic constriction | Ipratropium |
| Theophylline | Bronchodilator effect | Narrow therapeutic index |
| Montelukast | Blocks leukotriene receptors | Controller, not rapid rescue |
| Omalizumab | Binds IgE | Selected allergic asthma |
4. Rapid Revision Points — Last-Minute Revision
Must Remember:
- Asthma produces variable airflow obstruction because airway narrowing can change over time.
- Atopic asthma is linked to type 2 inflammation, IgE, mast cells and eosinophils.
- Airway remodeling includes subepithelial fibrosis and bronchial smooth-muscle enlargement.
- Bronchodilator reversibility on spirometry supports the diagnosis in a compatible clinical setting.
- Salbutamol acts through beta-2 receptors and increased cyclic AMP.
- Inhaled corticosteroids control inflammation rather than simply producing bronchodilation.
- Theophylline toxicity may produce serious arrhythmias and seizures.
- Cromolyn is preventive and does not rapidly reverse established bronchospasm.
- Before increasing long-term therapy, reassess diagnosis, adherence, inhaler technique and triggers.
- Occupational asthma prevention requires reduction or removal of the responsible workplace exposure.
KMU Exam Trap: Reduced wheeze in a worsening severely breathless patient may represent critically reduced airflow rather than recovery.
5. Clinical Memory Hooks
Episodic wheeze + bronchodilator-responsive obstruction
→
variable airflow limitation characteristic of asthma.
→
variable airflow limitation characteristic of asthma.
Asthmatic patient with tremor and palpitations after inhaler use
→
beta-2 agonist adverse effects.
→
beta-2 agonist adverse effects.
Wheezing worse at work and better on holidays
→
suspect occupational asthma and identify the workplace trigger.
→
suspect occupational asthma and identify the workplace trigger.
Severe breathlessness + exhaustion + markedly reduced air entry
→
life-threatening deterioration with risk of respiratory failure.
→
life-threatening deterioration with risk of respiratory failure.
6. ⭐ Starred High-Yield Exam Points
- ⭐ Asthma = chronic airway inflammation + bronchial hyperresponsiveness + variable airflow obstruction.
- ⭐ In allergic asthma, IgE-dependent mast-cell activation initiates the immediate response, while eosinophils contribute strongly to later inflammation.
- ⭐ Reversible or variable expiratory airflow limitation is a key diagnostic physiological clue.
- ⭐ Beta-2 agonist → increased cyclic AMP → bronchial smooth-muscle relaxation.
- ⭐ Inhaled corticosteroids are central controller drugs because they suppress the underlying airway inflammation.
- ⭐ A quiet chest with increasing distress is a dangerous sign of critically reduced airflow and possible impending respiratory failure.