Asthma

copyright (your organization) 2003 Definition: Asthma is a disease characterized by increased responsiveness of trachoebronchialtree to a multiplicity of stimuli clinically it is manifested by paroxysms of dyspnea,cough and wheezing. 5/16/2019 copyright (your organization) 2003

copyright (your organization) 2003 Epidemiology: Incidence diagnosed asthma may be around 2-6% of all population. ½ of cases develop before age of 10 1/3 of cases occur before age of 40 In childhood there is 2:1 male/female ratio which equalize by age 30. Incidence of disease is almost lower in underdeveloped societies. 5/16/2019 copyright (your organization) 2003

copyright (your organization) 2003 Pathogentic mechanism: 5/16/2019 copyright (your organization) 2003

copyright (your organization) 2003 Immunological mechanism: 5/16/2019 copyright (your organization) 2003

copyright (your organization) 2003 Mediators of the asthmatic reaction: Histamine Leukocyte chemo tactic factors Prostaglandins Leukotrienes Platelet activating factor (PAF) Kinins Adenosine 5/16/2019 copyright (your organization) 2003

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copyright (your organization) 2003 Provoking factors: We have seven major categories of stimuli that increase airway responsiveness and provoke acute attacks of asthma 5/16/2019 copyright (your organization) 2003

copyright (your organization) 2003 7 major categories: *Allergens (15-35%) *Pharmacological stimuli (beta adrenergic antagonist & aspirin other NSAID) *Infection *Air pollution *Occupational factors *Exercise (thermal & osmolarity changes may lead to release of bronchoconstrictior substance or to a neural bronchoconstriction reflex ) * Psychological factors 5/16/2019 copyright (your organization) 2003

copyright (your organization) 2003 Clinical features: 5/16/2019 copyright (your organization) 2003

copyright (your organization) 2003 Signs: Grade 1 A Able to carry out work with moderate difficulty . Sleep occasionally disturbed Grade 1 B Only able to carry out work with great difficulty. Sleep frequently disturbed. Grade 2 A Confined to chair or bed but able to get up with moderate difficulty. Sleep disturbed with little or no relief from inhaler. Grade 2 B Confined to chair or bed and only able to get up with great difficulty. Unable to sleep pulse over 130/min. Grade 3 Totally confined to chair or bed no relief from inhaler. Pulse over 120/min. Grade 4 Immobilized and completely exhausted. 5/16/2019 copyright (your organization) 2003

Changes in lung mechanics Peak Expiratory Flow rate (PEFR) Laboratory Finding Changes in lung mechanics FEV and FVC Peak Expiratory Flow rate (PEFR) Lung volumes *Reduction in airway diameter. *Increase in airway resistance With primary alteration in pulmonary mechanics and secondary changes in gas exchange. Pulmonary function tests are useful in that one can measure the degree of obstruction present it is reversible nature and demonstrate the air way hyper reactivity when combined with provoking factors. In patient with asthma 1st second FEV 30% also increase more than 20% in FEV Variability of greater than 15-20% in PEFR in a single day or from day to day is very suggestive of asthma and lowest value are recorded in early morning 5/16/2019 copyright (your organization) 2003

copyright (your organization) 2003 The End 5/16/2019 copyright (your organization) 2003