BRONCHIAL ASTHMA

 

MAIN TOPIC :

RESPIRATORY DISEASES

SUB TOPIC : BRONCHIAL ASTHMA

DEFINITION

Bronchial asthma is a medical condition which causes the airway path of the lungs to swell and narrow. Due to this swelling, the air path produces excess mucus making it hard to breathe, which results in coughing, short breath, and wheezing. The disease is chronic and interferes with daily working.

CLASSIFICATION

1. Aetiological:

a. Intrinsic or idiosyncratic asthma:

It occurs in 50% of asthmatics who are non- atopic. It can begin at any age, especially in late adulthood. There is no role for allergens in the production of the disease. A bronchial reaction occurs secondary to non- immunological stimuli, such as infections, irritating inhalants, cold air, exercise and emotional upset. These are severe and prognosis is less favorable.

b. Extrinsic asthma:

Onset is in childhood results from sensitization. Specific Immunoglobulins (IgE) are produced in response to allergens. There is positive family history of allergic disease. Extrinsic asthma is precipitated by allergens and accounts for 20% of asthmatics. Other symptoms include allergic rhinitis, urticaria, and eczema -prognosis is good.

2. Clinical

• Episodic Asthma

• Severe acute Asthma

• Chronic Asthma

PRECIPITATING OF FACTORS

• Cold air

• Tobacco smoke

• Emotional stress

• Drugs: Aspirin

Beta blockers (propranolol)

• Exercise

• Respiratory tract infection

• Chemicals

• Allergens

Dusts, pollen, fish, house mites, animal dander, grain dust, wood dust etc.

PATHOPHYSIOLOGY

 Early-Phase Response

 Peaks 30-60 minutes post exposure, subsides 30-90 minutes later.

 Characterized primarily by bronchospasm

 Increased mucous secretion, edema formation, and increased amounts of tenacious sputum

 Patient experiences wheezing, cough, chest tightness, and dyspnea.

 Late-Phase Response

 Characterized primarily by inflammation

 Increased airway resistance leads to air trapping in alveoli and hyperinflation of the lungs

 If airway inflammation is not treated or does not resolve, may lead to irreversible lung damage.

CAUSES

• Smoking and secondhand smoke.

• Infections such as colds, flu, or pneumonia.

• Allergens such as food, pollen, mold, dust mites, and pet dander.

• Exercise.

• Air pollution and toxins.

• Weather, especially extreme changes in temperature.

• Drugs (such as aspirin, NSAIDs, and beta-blockers)

CLINICAL FEATURES

There are three types of clinical presentation:

i. Episodic Asthma

ii. Chronic Asthma

iii. Severe Acute Asthma

a) Clinical features of episodic asthma

• Sudden onset

• Paroxysmal of episodic wheeze and dyspnoea

• No symptoms between episodes of asthma

• Episodes of asthma can be triggered by: allergens, exercise, viral infections or spontaneous.

b) Clinical features of chronic asthma

• History of allergy or respiratory tract infection

• Chest tightness, wheeze , dyspnoea on exertion

• Mucoid sputum

• Episodes of severe acute asthma can occurs

• Expiratory Rhonchi/wheezes

• Chest deformity if patient is suffering from childhood.

SYMPTOMS

• Severe breathlessness

• Patient couldn’t speak in words

• Cough with muco-purulent sputum.

SIGNS

• Decubitus

• Tachycardia, tachypnoea

• Pulsus paradoxus (>10mm Hg ) ( loss of pulse pressure on inspiration due to reduced cardiac return as a result of severe hyperinflation)

• Sweating

• Central cyanosis and bradycardia in severe hypoxia

• Chest finding

- Intercostal retraction

- Symptomatically diminished chest wall movement

- Hyper resonance on percussion note

- Silent chest in very severe case.

FEATURES OF SEVERITY

• Pulse rate > 100/min

• Pulsus paradoxus (>10mm Hg)

• Unable to speak in sentences

• PEF < 50% of expected

INVESTIGATIONS

i. Chest X-ray

• Hyperinflation

• Ruled out other lung pathology eg. Infection, Pneumothorax

ii. Lung function test:

VC, FEV, FEV1/VC: reduced

PEF : Reduced with morning dipping

iii. Arterial blood gas analysis

iv. Skin Hypersensitivity test for allergy

v. Others

• Blood TC, DC, Hb%; ESR

• Serum immunoglobulins

Total IgE: raised

Allergen – specific IgE – raised.

• Sputum: Gram stain, culture and sensitivity, eosinophils count in sputum

DIFFERENTIAL DIAGNOSIS

• Acute exacerbation of COPD

• Pulmonary Oedema

• Pulmonary embolus

• Upper respiratory tract obstruction

• Pneumothorax

MANAGEMENT

1. General management:

• Stop smoking

• Avoid precipitating factors

2. Hospital treatment:

• Assess severity of attack

• Start treatment immediately:

- Sit patient up and give high- dose O2 inhalation.

- Nebulization with Salbutamol with O2

- Hydrocortisone 200 mg iv prednisolone 30mg PO

- Chest X-Ray to exclude Pneumothorax

If life-threatening features are present

• Add Ipratropium 0.5 mg to the nebulized B2 agonist

• Give Aminophylline 250mg iv. Over 20mins. Avoid who is on oral thephylline or

Salbutamol or Terbutalin 0.25mg iv over 10 mins.

Further Treatment

 If improving:

• 40-60% O2+ prednisolone 30-60mg/Day

• Nebulized Salbutamol every 4 hour.

• Monitor peak flow and O2 saturation

 If patient is not improving after 15-30 minutes

• Continue 100% O2 inhalation and steroids

• Nebulized Salbutamol in every 15 minutes.

• Ipratropium 0.5 mg nebulized in every 6 hour.

 If not improving:

 Aminophylline infusion.

Monitoring the effects of Treatment:

Repeat PEFR 15-30min.,offer initiating treatment pulse oximeter monitoring SaO2>92%

Check blood gas analysis.

Once patient is improving

• Wean down and stop Aminophylline over 12-24hr.

• Reduced nebulized Salbutamol and switch to inhaled B-agonist

• Initiate inhaled steroids and stop oral steroids if possible

• Continue to monitor PEFR

• Look for the cause of the acute exacerbation and admission.

VACCINATION

• Influenza and pneumococcal vaccine are recommended for patient suffering from asthma.

PREVENTIVE MEASURES FOR ASTHMA

Asthma is not a totally preventable disease however the person should take precautions from allergen related to occupational exposure and household exposure.

• Use of face mask

• Avoid upper respiratory tract infection as much as possible.

• Avoid smoking and smoky environment

• Avoid passive smoking

INDICATION FOR REFERRAL/VENTILATION

• Coma

• Respiratory arrest

• Deterioration of ABG: hypoxia and hypercapnia

• Exhaustion, confusion and drowsiness

COMPLICATION

A. Exhaustion

B. Dehydration

C. Cor- pulmonale

D. Pneumothorax

E. Respiratory failure

SOME IMPORTANTNS:

1) What are long term effects of asthma?

Ans: Airway and lung damage, also known as airway remodeling, is a long-term process where chronic and uncontrolled inflammation from uncontrolled asthma causes irreversible scarring of the lungs and airways.

2) What will happen if asthma is not treated?

Ans: Asthma undiagnosed or untreated aggressively with medicines can lead to an increased risk of lung scarring. This is a permanent damage to our lungs and airways, and we cannot breathe properly forever unless with an external aid. This stage of asthma is irreversible i.e. it cannot be reversed with medications.

3) Can asthma damage your lungs?

Ans : Asthma can cause permanent damage to our lungs if not treated early and well.

Written by unknown buddies 🌸

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