Chronic Asthma
By Manoj Vaithilingam
What is Asthma
Phenotypes of Asthma
Pathophysiology (1)
• Basic concept: Airway inflammation decreases airway radius, leading
to decreased airflow.
Pathophysiology (2)
Pathophysiology (3)
Summary of Pathophysiology
Etiology
Diagnosis
NICE Algorithm for Diagnosis
BTS Guidelines for Diagnosis
Differential Dx
Treatment
• Key principles:
- Patient education and self-management plan
- Avoiding triggers and allergens (e.g. avoiding smoke exposure)
- No cure only management
1. Short and Long-acting Beta 2 Agonists
- MOA: Relax smooth muscle to relieve bronchospasm
- Ex of SABA: Salbutamol, Terbutaline
- Ex of LABA: Formoterol, Salmeterol
Treatment (2)
2. Corticosteroids (maintenance therapy)
- MOA: Decrease inflammation
- Ex: Budesonide, Beclomethasone
- Side effects: Systemic side effects if dose too high, oral candidiasis
3. Leukotriene antagonists
- MOA: Block leukotriene receptors in smooth muscle so reduces
bronchoconstriction
- Ex: Montelukast
- Side effects: Nausea and Headaches
Treatment (3)
4. Anti-IgE monoclonal antibodies
- MOA: Decrease IgE and thus, eosinophilic activity to reduce epithelial
destruction, mucus secretion and vagal bronchoconstriction.
- Ex: Omalizumab
- Side effects: Itching, joint pain, headache, nausea
Treatment
MART = maintenance and
reliever regimen, given every
day and if symptoms get
worse
Acute asthma - Types
Types
Treatment
OH SHIT
Treatment
1. Salbutamol – SABA (2.5-5mg/ 10 mins)
2. Hydrocortisone or Prednisolone – corticosteroid
- Hydrocortisone = IV 100-200mg QDS
- Prednisone = PO 40mg OD
3. Ipratropium Bromide - Muscarinic antagonist (parasympathetic NS)
- Bronchodilator as a result = 500mg every 4-6 hours
4. Magnesium Sulphate
- 1.2 -2g over 20 mins iv
- Used in acute severe asthma
When to admit to ICU?