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Terms in this set (160)

Airways narrow and swell, can produce extra mucus causing difficulty breathing. lung disease characterized by 1) airway obstruction that is reversible (but not completely in some patients) 2) airway inflammation 3) increased airway reactivity to a variety of stimuli
Pathology
· Periodic episodes
· Severe but reversible hyper responsiveness of the bronchi and bronchioles
· 2 basic types
Extrinsic asthma (allergic): 1/3 to ½ of all cases
Intrinsic asthma (non-allergic): develops in middle age with favorable prognosis
•Many have both
· 3 changes:
•Smooth muscle contraction
•Inflammation of the mucosa with edema
•Increased secretion of thick mucus
· Partial obstruction: leading to air trapping, air is pulled in; since expiration is a passive process, less force leads to trapped air. (causes residual volume to increase).
· Total obstruction: edema and mucus plugs lead to atelectasis or nonaeration of distal tissue, resulting in collapse of this secretion
· Status asthmaticus: persistent severe attack that may not respond to treatment. Note: can be fatal with hypoxia, acidosis, cardiac arrhythmias, CNS depression, and death.
· Etiology
· Exercise induced asthma
•Common in children
•Bronchospasm occurs within 3 minutes after exercise and usually resolves in 60 minutes
· Occupational asthma
•Results with occupational exposures to allergies (metals, textiles, dust)
· Drug-induced asthma
•Can be mild to severe. (Note: can be fatal due to anaphylactoid reactions)
· Manifestations:
· Cough
· Dyspnea
· Tight chest
· Tachycardia
· Hypoxia
· Respiratory alkalosis at first d/t hyperventilation
· Respiratory acidosis with air trapping and fatigue
· Respiratory failure: ABG with PO2 below 50, PCO2 above 50
· Diagnosis
· ABG
· Blood test: eosinophil count and IgE increased
· CXR
· Lung function tests
· Peak flow meter
· Treatment
· Prevention
· Acute attacks
•Beta2-adrenergic agent: relax bronchial smooth muscles - (rescue inhaler)
•Controlled breathing, supportive O2
•Glucocorticoids: e.g., Beclovent best at reducing secondary inflammation, IV steroids
· Prophylaxis
•Accolate: leukotriene receptor antagonist
•Singulair: block inflammatory response
•Cromolyn Sodium: decrease in chemical mediator response
•Theophylline: bronchodilator oral agent used less than in the past
•Environmental controls (ie - no smoking)