What are the different type of Asthma?
- Cardiac Asthma or Acute Pulmonary Edema and
- Bronchial asthma.
What is Cardiac asthma? What are the symptoms of Cardiac Asthma?
Cardiac Asthma is a synonym used for acute left heart failure or acute pulmonary edema. It is a condition characterized by transudation of fluid from pulmonary capillaries into the alveoli.
What are the Common causes of cardiac asthma?
- Mitral valve disease (stenosis and incompetence).
- Aortic valve disease (stenosis and incompetence).
- acute myocardial infarction and
Precipitating factors of cardiac Asthma
- Infective endocarditis.
- Massive myocardial infarction.
- Acute rheumatic or viral myocarditis.
- Fluid overload.
- Severe physical exertion.
Pathophysiology – Cardiac Asthma
In cardiac asthma, there is increase in pulmonary venous pressure (backward failure); dilated lymphatics are seen in persons with long standing raised capillary pressure.Impairment of gas exchange causes hypoxia which in turn causes worsening of cardiac asthma.
Clinical features – Cardiac Asthma
- Individual is acutely dyspnoeic, restless, often cyanosed and profusely sweating.
- Respiration is rapid and accessory muscles are moving.
- Person has frothy pink sputum.
- Pulse is rapid and has pulses alternans characters.
- Auscultation reveals rales and ronchi all aver chest.
- Chest X-ray reveals classical Bat’s wing appearance.
- Kerley’s B lines due to thick and tense lymphatics.
Treatment for Cardiac Asthma>
- It is usually an emergency and should be treated in intensive care unit (ICU).
- Propped position should be given.
- Oxygen supply should be given.
- Frusemide intravenously should be given.
- Aminophylline to reduce broncho-spasm and improve cardiac contractility.
- Digitalis in presence of tachy-arrhythmias.
- Inotropic drugs should be given in presence of hypotension.
- Ventilation in case of hypoxia in spite of oxygen therapy.
What is Bronchial Asthma? What are the symptoms of Bronchial Asthma?
It is characterized by episodic airflow obstruction, which is initially fully reversible.
Bronchial hyper-responsiveness is usually responsible for bronchial asthma.
Factors causing hyper-responsiveness bronchial asthma
- Allergens e.g. pollen, hose-dust and mites.
- Drugs like NSAIDS, particularly aspirin.
- Inhalation of cold air.
- Viral infection of respiratory tract.
- Environmental pollution, cigarette smoke, strong scents and perfumes, fumes of petrol and vapors.
- Autonomic nervous system imbalance.
Pathology – bronchial asthma
On gross examination lungs are hyper-inflated and fail to collapse on opening the chest.
Large and small bronchi are plugged with thick tenacious mucus.
Clinical features – bronchial asthma
Classical symptoms are intermittent reversible attacks of dyspnoea, wheezing and cough.
Cough is usually non-productive.
During acute attack, person may be restless, anxious, sweating, orthopnoic and breathing through pursed lips with prolonged expiration.
Investigations – bronchial asthma
- Eosinophilia is not uncommon.
- Chest X-ray shows inflated lungs and may help in detecting chest infection.
- Arterial blood gas (ABG) shows earliest abnormality like respiratory alkalosis with hypoxia.
- Pulmonary function test (PFT) shows decreased lung volume, decreased in FVC (forced vital capacity).
Management of Bronchial Asthma
- Prevention- avoid flowers, pollens, pets and chemicals. Identify food allergy and avoid them. Keep house dust free.
- Chronic asthma-occasional episodes should be tackled with B-agonists as and when required. Frequent episodes should be tackled with regular inhalation of broncho-dilators. In chronic asthma high doses of steroids and brocho-dilators are inhaled.
- Acute attacks- B-agonists are to be inhaled like salbutamol and terbutaline. Nebulisation with broncho-dilators with or without oxygen.