Bronchial Asthma Clinical Features, Complications Investigations, Treatment And Prevention

Bronchial Asthma

Question. Write a short note on bronchial asthma.
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Describe in brief bronchial asthma.
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Describe briefly the management of bronchial asthma.
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Outline the management of allergic bronchial asthma.
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Describe clinical features, diagnosis, and management of bronchial asthma.
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Describe the clinical features of bronchial asthma.
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Discuss clinical features, complications investigations, and treatment of bronchial asthma.
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Write a short answer on bronchial asthma.
Answer. Bronchial asthma consists of an increased responsiveness of the bronchial tree, which is characterized by frequent attacks of dyspnea due to generalized bronchial constriction.

Etiology bronchial asthma.

1. Genetic and environmental factors also cause bronchial asthma.
2. Early onset asthma starts in childhood, there should be a family history of atopy, i.e. external antigen, and other allergic disorders, i.e. urticaria, allergic rhinitis, and eczema. In this, skin tests are positive for allergies and there are high levels of IgE antibody in serum.
   There is a positive response to provocative tests that involve in inhalation of specific antigens.
3. Late-onset asthma occurs in adulthood. In this, there is no effect of atopy along with no family history of allergens.
   Skin tests are normal and there are no increased levels of IgE antibody in serum.

Read And Learn More: General Medicine Questions and Answers

Various Trigger Factors for Bronchial Asthma

1. Night or early morning
2. Exercise (especially running)
3. Cold air, fog
4. Viral respiratory tract infection
5. Allergens (for example, house dust, mite, cat fur)
6. Nonspecific irritants (for example, cigarette smoke, perfumes, paints)
7. Drugs (for example, B­blockers, aspirin, NSAIDs)
8. Emotion or stress
9. Occupational exposure

Clinical Features bronchial asthma.

1. Symptoms of bronchial asthma can be episodic or persistent.
2. Asthma is characterized by paroxysms of dyspnea, cough, and wheezing commonly in children and young adults.
3. Attcks can be mild or severe or may last for hours, days or rarely weeks.
   Between episodes, the patients become asymptomatic.
4. In older patients, asthma is chronic and persistent.
5. Symptoms get worse in the early morning.
6. On examination, there is tachypnea, tachycardia as well as involvement of accessory respiratory muscles.
7. Breath sounds become harsh, and vesicular with prolonged expiration.
8. A prominent wheeze should be audible in both phases of respiration.
9. Acute severe asthma is a life-threatening attack of asthma which is previously called status asthmaticus.
10. This patient may additionally have tachycardia, pulsus paradoxus, cyanosis, and active accessory respiratory muscles.
11. The air entry is drastically reduced with a silent chest on auscultation.
12. The patient may become confused or drowsy.

Investigations of bronchial asthma.

1. Chest radiograph may be normal, or show signs of segmental or lobar collapse.
2. Full blood count reveals eosinophilia.
3. Sputum: On examination eosinophils, Charcot­Leyden crystals and at times Curschmann‘s spirals may appear purulent (due to eosinophilic leucocytes) in the absence of infection).
4. Skin tests: A patch test is done with an aqueous solution of the substance to be tested. A positive test indicates wheal and flare. Tests are performed with groups of substances or allergens which produce asthma.
5. Lung function test: Spirometry shows a reduction in FEV1, FEV1/FVC ratio, and peak expiratory flow rate (PEFR).
   Reversibility, which is one of the characteristic features of asthma, is shown by a 200 mL increase in FEV, 15 minutes after inhaling a short-acting β2 agonist or a 2-4 weeks trial of oral corticosteroids.
6. Provocation (challenge) tests: Exercise challenge tests are useful in young adults and can be used to confirm the diagnosis of asthma, since a fall in FEV, or PEFR occurs after 5­7 minutes of vigorous exercise in most patients with asthma.
7. IgE and IgE specific test: Elevation of total serum IgE supports the diagnosis of atopy, and measurement of fractions of IgE specific to one allergen, radioallergosorbent test (RAST) can be useful in some patients in whom a specific allergy is suspected.

 

 

 

Management of acute severe asthma

1. Treatment of severe acute asthma at home:

1. Administer oxygen (40-60%) through a mask, if available.
2. Bronchodilator: IV Aminophylline, i.e. 250-375 mg in 20 mL of saline slowly after checking blood pressure Or IV, Salbutamol 250 µg in 20 mL of saline over 10 min Or IV Terbutaline 250 µg in 20 mL of saline over 10 min.
3. Alternatively:

1. Salbutamol (5 mg) or terbutaline (10 mg) by nebulizer.
2. Give hydrocortisone sodium succinate 200 mg IV stat.
3. Arrange for emergency admission to a hospital in an ambulance equipped with oxygen therapy.
4. Give prednisolone 60 mg orally

2. In-hospital treatment:

1. A high concentration of oxygen, i.e. 40–60% at a high flow rate should be given.
   It is recommended in all cases even in the presence of CO₂ retention.
   Oxygen supply should be started immediately through mask,and concentration adjusted according to blood gas measurement.
   PaO 2 of greater than 8.5 to 9.0 kPa should be maintained, if possible.
2. High doses of salbutamol, i.e. 2.5–5 mg or terbutaline 5–l0 mg by nebulizer should be given initially and repeated after 30 minutes, if necessary.
   If no improvement occurs with nebulized therapy, then 250 µg of salbutamol or terbutaline may be given by IV infusion over 10 minutes.
3. In all severe cases of acute asthma systemic corticosteroids, i.e. hydrocortisone 200 mg I.V. stat and then 4 to 6 hourly or oral prednisolone 40–60 mg/day to tide over the crisis.
4. Systemic bronchodilators such as aminophylline 250 mg IV over a period of 30 minutes may be given immediately followed by either 8-hour doses or continuous infusion not exceeding a total dose of 1.5 g/day.
5. Ipratropium bromide can be used in acute severe asthma in doses of 0.5 mg added to a nebulized beta-agonist.
   • Reassess the patient by PEFR and arterial blood gas analysis. If recovery is good, then continue oxygen therapy and oral prednisolone, i.e. 40 mg/day in decreasing doses is given.
   • Nebulized β-adrenoreceptor agonist may be continued every 4–6 hours and then replaced by metered dose inhalation.
   • IV hydrocortisone 200 mg 6 hourly may be continued for 24–48 hours in severe cases followed by oral steroids.
   • If the response is not good, then shift the patient to respiratory intensive care for assisted ventilation.
6. Assisted ventilation: Mechanical ventilation can be life-saving in a few patients who are critically ill.

Management of chronic asthma For the management of chronic bronchial asthma, a stepwise approach is chosen according to the severity of the disease. Once the disease is controlled, a step-down therapy should be attempted.

1. Step 1: Use of inhaled bronchodilators: Here inhaled shortacting β2 adrenoreceptor agonists bronchodilators such as salbutamol or terbutaline 100 to 200 μg are used as needed for minor symptoms.
2. Step 2: Use of bronchodilators with regular use of inhaled antiinflammatory agents: If the symptoms are not controlled by inhaled adrenergic drugs, then a low dose of inhaled steroid is added i.e. beclomethasone disproportionate or budesonide up to 800 μg twice a day.
3. Step 3: Use of bronchodilators with high doses of steroids: The dose of inhaled steroids is increased to 800–2000 μg a day.
4. Step 4: Use of of high-dose corticosteroids and bronchodilators with the therapeutic drug: In addition to drugs used in Step 3, An inhaled long­acting adrenergic agent such as salmeterol or formoterol can be added or sustained released theophylline can be used orally or inhaled ipratropium bromide or sodium cromoglycate are tried.
5. Step 5: Addition of oral steroids: Regular oral steroid, i.e.prednisolone 20–30 mg/day in single dosage is added to Step 4 regimen to control symptoms.

Patient education and Monitoring of therapy

1. Educate the patients about the nature of the disease as well as its treatment.
   Patients are trained to recognize the severity of their disease and monitor the response to therapy with the use of a peak flow meter.
2. Demonstrate the proper use of inhalation devices such as metered­dose inhalers (pressurized aerosol system),rotahaler (dry powder system) and nebulizers.
3. Encourage the usage of inhaler therapy because it is effective in lower dosages together with a rapid onset of action and has fewer side effects.