Bronchial Asthma Dr. Saraswathi Ramesh

Definition Obstructive pulmonary disease characterised by hyper-responsiveness of bronchial mucosa causing narrowing of the bronchi in response to a wide range of stimuli resulting in cough, wheeze, thightness of chest and shortness of breath which is worst during night

Types Atopic or Early onset / Extrinsic Late onset (Non-atopic) / Intrinsic

Applied Anatomy & Physiology Upper Respiratory tract Nose, Nasopharynx, Larynx Lined by vascular mucous membrane with ciliated epithilium Lower Respiratory tract Trachea, bronchi Lined by ciliated epithilium as far as terminal bronchioles

Applied Anatomy & Physiology Larynx and large bronchi are richly supplied with sensory nerve receptors involved in the cough reflex. Acinus is the gas exchange unit of the lung and comprises branchning respiratory brochioles leading to clusters of alveoli

Incidence 10-20% population Prevalence increasing Mortality due to asthma unchanged inspite of medical advances

Aetiology Allergens Skin test positive Skin test negative Early Onset Extrinsic Atopic Infection Exercise Environment Occupation Drugs Emotion Late Onset Intrinsic Non-atopic Skin test positive Family history of allergic disorders Skin test negative Family history absent

Clinical Features Episodic Asthma No symptoms between episodes Paroxysms of wheeze and dyspnoea Triggered by allergens, exercise, viral infections, eg. cold

Clinical Features Severe Acute Asthma Was known as ‘status asthmaticus’ Life-threatening situation Orthopnoea Unproductive cough with respiratory distress Tachycardia, pulsus paradoxus, sweating, central cyanosis

Clinical Features Chronic Asthma Chest tightness, wheeze, breathlessness on exertion Spontaneous cough and wheeze during night Episodes of severe acute asthma with respiratory infection

Clinical Features During the attack the chest is held in the position of full inspiration Decreased breath sounds with ronchi ‘silent chest’ during severe attack ‘pigeon-chest’ deformity

Investigation X-ray Chest Pulmonary function tests FEV1, VC, PEF Arterial blood gases PaO2, PaCO2 Skin hypersensitivity tests

Preventive Measures Pollens Try to avoid exposure to flowering vegetation. Keep bedroom windows closed Mites in house dust Vacuum clean mattress daily Shake out blankets daily Dust bedroom thourghly Animal dander Avoid contact with dogs, cats, horses or other animals

Preventive Measures Feathers in pillows or quilts Substitute latex foam pillows and terylene quilts Drugs (eg, beta-adrenoceptor antagonists) Avoid all preperations of relevant drugs Foods Identify and eliminate from diet Industrial chemicals Avoid exposure or change occupation

Management Hyposensitization Subcutaneous injection of initially very small, but gradually increasing doses of extracts of allergens

Chronic persistent asthma 5 4 plus regular oral steroids 4 3 plus regular bronchodilators 3 High dose inhaled corticosteroids 2 Regular inhaled corticosteroids – small dose 1 Occasional short-acting-Beta2-adrenoceptor agonists

Acute Severe Asthma Oxygen High doses of inhaled beta2 adrenoceptor agonists Systemic steroids Assisted ventillation

THANK YOU