BRONCHIAL ASTHMA-reversible obstructive airway disease caused by hyper reactivity of bronchial tree to a variety of stimulus.

 

BRONCHIAL ASTHMA

 

Asthma is defined as inflammatory disorder of airway in which many cells play an important role. Asthma is also reversible obstructive airway disease caused by hyper reactivity of bronchial tree to a variety of stimulus.

 

Incidence

 

            5% of asthma occurs in school age children. The onset of asthma usually occurs during the first 5 years of life.

 

Causes

 

1)      Bronchospasm and airway obstruction: - This obstructive process is due to increased responsiveness of the bronchi to anyone or combination of diverse group of factors called as triggers.

2)      Extrinsic causes :- The term extrinsic asthma or allergic asthma is used when the symptoms are induced by hyper immune response to the inhalation of specific allergents.

Example : feathers, house dust , pollens etc.

 

3)      Intrinsic causes :-  The intrinsic asthma refers to same clinical manifestation, airway is not produced by hyper immune response. I may be due to as follows:-

·         Family history of asthma.

·         Hyper reactive airway.

·         Inhalation of irritants such as cigarette smoke, strong odours of soap and perfumes.

·         Exercise .

·         Drugs (especially aspirin)

·         Changes in the temperature.

·         Viral respiratory tract infection.

·         Emotional stress.

 

Pathophysiology

 

            Pathologic mechanisms responsible for the airway obstruction are associated with asthma or the same.

 

            Spasm of the smooth muscle of the bronchi, oedema of the bronchial mucosa.

 

            It leads to increased secretion and accumulation of thick tenacious mucus.

           

            These obstructive processes interfere with ventilation and result in symptoms of Dyspnea, chon chi and coughing.

 

 

 

Clinical Manifestations

 

            Clinical manifestation of bronchial asthma in children are dependent on degree of airway obstruction:-

·         Dyspnea

·         Wheezing

·         Coughing with or without expectoration of sputum

·         Some children are continuously symptomatic and have intermittent episode of more severe airway obstruction.

·         Chronic coughing may be preceded present at night.

·         An episode of asthma may be preceded by nasal congestion.

·         Young children may appear to have shorter breath.

·         Older children may complain of tight feeling in the chest.

·         Respiratory rate is increased.

·         Expiratory phase of respiration is prolonged.

·         If the attack progresses further, the child becomes- vomiting , complaints of chest pain and abdominal pain.

·         Breath sounds are diminished.

·         Co₂   retention may produce signs as follows-

 

-          Headache

-          Muscle twitching

-          Confusion

-          Coma

 

·         Diagnostic evaluation :-

 

1.      History – The Family is very important specially when wheezing is noted for the first time. Information about frequency, duration, severity and rapidity of onset of symptoms should be noted.

 

2.      Physical examination –

 

-          Height and weight should be routinely measured.

-          Percussion over the lungs field is hyper resonance, because of air trapping in the alveoli.

-          Wheezing on inspiration may be present.

 

3.      Total WBC count is elevated – During an asthma attack. The eosinophil count is elevated in both extrinsic and intrinsic asthma.

 

4.      Chest x-rays help in identifying – Bilateral hyperinflation, bronchial thickening atelectasis etc.

 

5.      Pulmonary function test – Spirometry, which measure forced expiratory volume and forced vital capacity. These values are decreased in airway obstruction.

 

Management:

 

1.      Medical Management :- Drug therapy help in promoting bronchodilation, reducing inflammation and removing secretions.

 

-          Aminophilline – Given intra-venously , is limited to use in acute episodes of asthma that requires hospitalization.

-          Isoproterenol – The dosage of the drugs is 0.2 to .03 ml in 2.5 ml saline by aerosol and is inhaled B-adrenergic stimulants. It acts quickly and short duration which produces Bronchospasm.

 

Asthalin solution by nebulizer as per recommended.

 

-          Metaproteremol – The dosage of the drug is 0.2 to .03 ml in 2.5 ml saline by inhalation.

 

·         Corticosteroids – (Methyl prednisolone) the dosage of the drug is 2 mg / kg / intravenously, but the exact mechanism of action of corticosteroids in asthma, is unknown & it may reduce inflammatory response.

·         Cromolyn sodium – It block the release of chemical mediators from the mast cells. It produces indirect vasodilatation. It is used to prevent attacks and is the most effective in children with extrinsic asthma.

 

Home care management bronchial asthma

 

·         Child should not be exposed to extreme weather.

·         Environment should be free from allergens such as pollens, dust etc.

·         Intake of alcohol & smoking is avoided.

·         Asthalin nebulization.