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Asthma
Respiratory
Wheeze
Cough
Shortness of breath
Asthma is a chronic inflammatory airway disease characterized by reversible airway obstruction and bronchial hyper-responsiveness. It manifests as episodes of wheezing, cough, and dyspnoea, often with nocturnal worsening.
🎯 Key Learning Objectives
- Diagnose asthma using FeNO levels and spirometry with reversibility.
- Describe the 'step-up/step-down' management ladder.
- Recognize life-threatening asthma features (Peak flow <33%, silent chest, cyanosis).
- Manage acute exacerbations with oxygen, salbutamol, and corticosteroids.
- Counsel patients on correct inhaler technique and peak flow monitoring.
- Explain the role of inhaled corticosteroids (ICS) in preventing airway remodeling.
🔬 Pathophysiology
Type 2 helper T-cell (Th2) mediated response triggers eosinophilic inflammation, mucus hypersecretion, and smooth muscle contraction (bronchospasm) in response to triggers like allergens or viruses.
🩺 Clinical Features
Symptoms
- Wheezing (worse at night/early morning)
- Cough
- Chest tightness
- Shortness of breath
Signs
- Expiratory wheeze
- Tachypnoea
- Hyper-resonant chest percussion
- Use of accessory muscles in severe cases
🔬 Investigations
🛏️ Bedside
- Peak Expiratory Flow Rate (PEFR)
- Spirometry
🩸 Bloods
- IgE levels
- Eosinophil count
- ABG (in acute severe cases)
📷 Imaging
- CXR (usually normal; used to exclude pneumothorax in crisis)
⚗️ Special
- Fractional exhaled Nitric Oxide (FeNO)
- Direct bronchial provocation (methacholine)
💊 Management
🚨 Acute Management
- Oxygen (target 94-98%)
- Salbutamol nebulisers
- Ipratropium bromide
- Prednisolone 40mg PO or Hydrocortisone IV
📋 Long-Term
- SABA (as needed)
- Low-dose ICS (Maintenance)
- Leukotriene Receptor Antagonist (Montelukast)
- LABA (e.g. Salmeterol)
🏃 Lifestyle
- Smoking cessation
- Weight loss
- Avoidance of triggers (pets, dust mites)
- Written asthma action plan
⚠️ Complications
Status asthmaticus
Respiratory failure
Pneumothorax
Pneumomediastinum
⭐ High-Yield Pearls
- A normal pCO2 in an exhaustive asthma attack is a 'life-threatening' sign (indicates tiring).
- Salbutamol can cause hypokalaemia and tremor.
- Always review inhaler technique before escalating medication.
- Diagnosis in adults: FeNo >= 35 ppb AND positive bronchodilator reversibility.
- Occupational asthma should be considered in adults with new-onset symptoms.
📖 GUIDELINES:
NICE NG80
BTS/SIGN Asthma Guidelines
❓ Practice Questions
Q1. A 64-year-old woman presents with sudden onset shortness of breath and pleuritic chest pain. She underwent a total hip replacement two weeks ago. Her observatio…
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Q2. A 22-year-old man presents to the Emergency Department with an acute asthma exacerbation. He is unable to complete sentences in one breath, his respiratory rate…
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Q3. A 68-year-old male with known COPD presents with increasing breathlessness and productive cough with green sputum. On examination, he is stable but has widespre…
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