Today is our topic of discussion Bronchial Asthma
Bronchial Asthma
Definition:
Asthma is a chronic inflammatory disorder of the airways, characterized by reversible airflow obstruction due to hyper-responsiveness of airways to multiple stimuli manifested as cough, wheeze, chest tightness and shortness of breath.
Types:
1. Extrinsic or atopic asthma: Hypersensitivity or immune-mediated reaction to foreign antigens; begins in childhood; series of chemical and structural changes occur in the bronchi.
2. Intrinsic or non-atopic: Non-immune reaction. Examples – aspirin, virus, stress, exercise.
Pathology:
Inflammation in the airways due to some inciting agent resulting in spasm and narrowing of the airways. This causes difficulty in expiration rather than inspiration.
Common asthma triggers/precipitating factors:
1. Animals (pet hair or dander)
2. Dust & pollen
3. Changes in weather (most often cold weather)
4. Chemicals in the air or in food
5. Exercise
6. Respiratory infections, such as the common cold
7. Strong emotions (stress)
8. Tobacco smoke
9. Virus
10. Aspirin and other NSAIDS (diclofenac) and beta-blockerson
Clinical features:
1. Cough with or without sputum (phlegm)
2. Pulling in of the skin between the ribs when breathing (intercostal retractions)
3. Shortness of breath that gets worse with exercise or activity
Wheezing:
a. Comes in episodes with symptom-free periods in between
b. May worse at night or early morning
c. May go away on its own
d. Gets better by bronchodilators
e. Gets worse when breathing cold air, exercise, acid reflux or heartburn
f. May begin suddenly
Signs:
1. Chest wall deformity, such as, pigeon’s chest (atopic asthma from childhood)
2. Chest wall movement diminished symmetrically.
3. High pitched ronchi (especially in expiration).
Features of Acute Severe Asthma/Status Asthmaticus:
1. Tachycardia (pulse >120/min) and tachypnoea (RR 25/min).
2. Cyanosis (bluish color to the lips and face).
3. Decreased level of alertness (severe drowsiness, confusion and extreme difficulty in breathing).
4. Inability to complete the sentence in speech.
5. Severe anxiety due to shortness of breath.
6. Sweating
Investigation:
1. X-ray chest P/A view (hyperinflated lungs)
2. Total circulating eosinophil count (increased)
3. Lung function tests:
a. PEFR (reduced)
b. VC (reduced)
4. Arterial blood gas analysis
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