Transcript Asthma
Dr Dhaher Jameel Salih Al-habbo FRCP London UK Assistant Professor Department of Medicine.College of Mdicine University of Mosul Chronic Bronchitis Emphysema COPD Airflow Obstruction Asthma Asthma and Allergic asthma Chronic Inflammatory disorder of Bronchi characterized by ,Episodic, reversable Brochospasm resulting from an exagurated Bronchconsrector response to a various stimuli(allergy). Affects 10% of children& 5-7% adults 1-Childhood asthma occurs in atopic individuals who produce IgE on exposure to small amounts of common antigen. 2-Asthma in adults is called non-atopic, intrinsic or late-onset asthma. 3-First degree relatives of asthmatics have higher prevalence for asthma. Environmental factors 1-Indoor environment and childhood exposure to allergen is very important in determining sensitization. 2-House dust mites and pet-derived allergens are wide spread in houses. 3-Fungal spores, cockroach antigens and nitrogen dioxide (gas cockers). Environmental factors ;Out door like ; ozone, sulphur dioxide and air-borne particles,smoking,Drugs and infection. Extrinsic (Allergic/Immune) ◦ Atopic - IgE ◦ Occupational - IgG ◦ A. Bronchopulomonary Aspergillosis - IgE Intrinsic (Non immune) ◦ Aspirin induced ◦ Infections induced Inhaled allergen rapidly interacts with mucosal mast cells (IgE-Dependent mechanism). This will results in histamine and leukotrienes release leading to bronchoconstriction. Airway edema, increased volume and size of sub mucosal glands. desquamation of airway epithelial cells. 1-Wheeze, breathlessness, cough, and sensation of chest tightness usually episodic especially in children and atopic. 2-chronic and persistent wheeze is more common in older non-atopic patients with adult asthma and it may be difficult to be differentiated from COPD. 3-Typically, there is diurnal variation in symptoms and peak expiratory flow measurement being worse in the early morning. Cough and wheeze usually disturb the patient sleep (Nocturnal asthma). There may be cough with no wheezes (cough variant asthma). 4-Symptoms may provoked by exercise (exercise-induced asthma). 5-Acute sever asthma: Patient usually extremely distressed, using accessory muscles of respiration, the chest is inflated and the patient is tachypnoeic. Pulsus paradoxus (loss of pulse pressure on inspiration due to reduce cardiac return due to sever hyperinflation) and sweating. Central cyanosis in sever cases with silent chest and bradycardia. Spirometric measurement of FEV1/VC ratio or PEF before and after bronchodilators provide reliable indication of the degree of airflow obstruction, relation to exercise &the reversibility after bronchodilators. Radiological. Arterial Blood Gas analysis(ABGA) 1-Patient education: A-The patient should be able to differentiate between reliever (bronchodilators) and preventer (anti-inflammatory) medications B-The patient should be fully capable of using the inhaler devices. C- The patient should be fully capable of using the peak flow meter, to understand the readings, to determine his personal best measurement and to record all these information in his personal action plan. The rescue course is in the form of *- 30-60mg prednisolone orally daily *-Continue as single morning dose until 2days after good control of the symptoms. *-Tapering the dose to withdraw is required only if we continue treatment for 3 weeks and more. A- Oxygen should be given at the highest concentration. To maintain a PaO2 of >8.5-9KPa. B-High dose of inhaled 2-adrenoceptor agonist nebulised using oxygen (salbutamol 2.5-5mgor terbutaline5-10mg) repeated within 30 minutes if necessary. Inhaled 2-adrenoceptor agonist can be given out side hospital by large volume spacers. C-Systemic steroids; 30-60mg prednisolone orally or intravenous 200mg hydrocortisone. *-Ipratropium bromide 0.5mg should be added to nebulised 2-adrenoceptor agonist. *-Continue nebulised 2-adrenoceptor agonist every 15-30 minutes as necessary. *-Magnesium sulphate (25mg/kg i.v, maximum 2gm) *-Mechanical ventilation. Duration Duration and Administration of Inhaled Bronchodilators Sutherland, E. R. et al. N Engl J Med 2004;350:2689-2697