Understanding Bronchial Asthma: Causes, Symptoms, and Management

What is Bronchial Asthma

Asthma can be defined as a reversible chronic obstructive disorder of the airways characterized by recurrent episodes of coughing, wheezing and dyspnea in people with airway hypersensitivity to various stimuli. It is the most common chronic disease of childhood.

Symptoms typically begin before 8 years. The severity of symptoms decrease during adolescence in some children.

Causes of Bronchial Asthma

• Hereditary
• Viral infection. E.g. Rhinovirus
• Allergies
• Allergens - mould, pollen, animal dander, dust, weeds
• Physical exertion - exercise, laughing, coughing
• Emotional stress
• Sudden cold exposure
• Air pollutants - cigarette smoking, strong odour or perfumes
• Medications such as NSAIDs

Types of Bronchial Asthma

• Extrinsic asthma:This is a hyper sensitivity reaction to inhalant allergens. Patients usually have family history of allergy and/or past history of allergy. It usually begins in childhood.
• Intrinsic asthma:Here, no inciting allergen is implicated. Triggering factors include viral infections, respiratory tract infections and exercise. It usually occurs above 35 years.
• Mixed asthma:This is the commonest form of asthma that combines the characteristics of both extrinsic asthma and intrinsic asthma.
• Others include:
• Aspirin induced asthma
• Exercise induced asthma
• Occupational asthma - inhalation of industrial fumes and gases

Pathophysiology of Bronchial Asthma

When an allergen is introduced to the body, it causes formation of sensitizing antibodies such as immunoglobulin E. Immunoglobulin E antibodies bind to tissue mast cells and basophils in the mucosa of the bronchioles, lung tissue, and nasopharynx. An antigen-antibody reaction releases primary mediator substances such as histamine and bradykinins.
These mediators cause inflammation, which leads to swelling of the membranes that line the airways (mucosal edema), thereby reducing the airway diameter. There is also contraction of the bronchial smooth muscle that encircles the airways (bronchospasm), causing further narrowing and obstruction.
In addition, the mucous glands increase in number and hypertrophy. The goblet cells secrete thick mucus into the airways. These changes cause further obstruction. The nervous system becomes stimulated.
This increases the bronchomotor tone, and results in bronchoconstriction. The lungs become hyperinflated with decreased elasticity and compliance, increased forced breathing and dyspnea. This causes impaired gas exchange which leads to coughing, wheezing and chest tightness.

Signs & Symptoms of Bronchial Asthma

• Cough (with or without mucus production) - this becomes worse at night
• Wheezing attacks - this occurs frequently at night
• Chest tightness
• Slow laborious wheezing breathing (forced expiration)
• Dyspnea
• Cyanosis
• Profuse sweating
• Tachycardia
• Cold extremities
• Orthopnoea - patient sits upright and uses accessory muscles of respiration
• Restlessness
• Anxiety
• Nasal flaring
• Fatigue

Diagnostic Investigations of Bronchial Asthma

• History taking and physical examination
• Arterial blood gas measurement and pulse oximetry reveal hypoxemia
• Skin hypersensitivity test to identify allergen
• Chest X-ray
• Full blood count for WBC count

Medical Management of Bronchial Asthma

• Bronchodilators - aminophylline, salbutamol solution through nebulizer
• Corticosteroids such as prednisone, hydrocortisone to decrease airway inflammation
• Anticholinergics such as atropine for relief of airway obstruction
• Oxygen therapy for hypoxia
• Cough syrup (expectorant) for cough
• Antibiotics - penicillin

Nursing Management of Bronchial Asthma

The following are the measures to put in place in the care of a hospitalized person diagnosed of bronchial asthma

1. Place patient in fowler’s or sitting up position
2. Loosen all tight clothing around the neck, chest and waist
3. Monitor and record vital signs
4. Assess the patient’s skin colour for changes
5. Administer and record prescribed oxygen
6. Administer prescribed medications and monitor for their desired and side effects
7. Encourage fluid intake to liquefy secretions
8. Monitor and record intake and output chart
9. Maintain personal hygiene
10. Nurse patient in a well ventilated room in a non-allergic environment.
11. Monitor colour, consistency and amount of sputum produced.
12. Teach patient deep breathing and coughing exercise.
13. Assess signs of dehydration.
14. Reassure patient and family to allay fears and anxiety.
15. Assist patient in stress control and to avoid stress.
16. Help patient to identify triggering factors and avoid them.
17. Assist patient to attend asthmatic clinic regularly for review.
18. Educate patient how to use inhalants. Educate him/her to keep more than one and carry it at all times.
19. Educate patient to use the bronchodilator inhalers first, before using the steroid inhalers.
20. Explain to patients on steroid inhalers need to rinse their mouths out after using them to avoid getting thrush.
21. Ask questions that can be answered by nodding or a brief one-word answer so that the patient can conserve energy for breathing during acute attacks.
22. If the patient is a child, allow the parents to stay with the child during acute attacks.
23. Give moderate protein to patient to boost his or her immunity.
24. Serve patient with high carbohydrates diet.
25. Serve food in bits and at frequent intervals.
26. Explain that any dyspnea unrelieved by medications, and accompanied by wheezing and accessory muscle use, needs prompt attention from a healthcare provider.