Asthma Flashcards
Severe obstruction persisting for days to weeks
STATUS ASTHMATICUS
10-20% adults
15% of children
Very common
Immense social impact
Prevalence is rising
All ages; 1/2 before 10 years old
With a peak of age of 3
M:F = 2:1; equalizes by 30 years old
Heterogenous
Genetic and environemental factors contribute to initiation and continuance
ASTHMA
Single largest risk factor of asthma
ATOPY
House dust mite
DERMATOPHAGOIDESTERONYSSINUS
Major risk factors for asthma deaths
Poorly controlled disease with frequent use if bronchodilator inhalers
Lack of corticosteroid therapy
Previous admissions to hospital with near-fatal asthma
Characteristicphysiologic abnormality of asthma
AIRWAY HYPERRESPONSIVENESS
Excessive bronchoconstrictor response to multiple inhaled triggers (allergens, exercise, hyperventilation, fog, irritant dusts and sulfur dioxide)
Inflammationis initiated in the respiratory mucosa from the trachea to terminal bronchioles
Persistent subacute inflammatiom of the airways
Asymptomatic
Airways edematous and infiltrated with inflammatory cells
Increased cellularity, glandular hypertrophy, epithelial denudation
Mast cells, eosinophils, lymphocytes, airways epithelial cells
Reduction in forced expiratory volume in 1 second (FEV1), FEV1/FVC (forced viral capacity) ratio and PEF (peak expiratory flow) and increase in airway resistance
Early closure of peripheral airway results in lung hyperinflation and increased residual volume
Asthma
R duced ventilatioj, increased pulmonary blood flow, ventilation-perfusion mismatch
Severe asthma
Hyperinflated lungs
Plugging of airways
Hypertrophy of bronchial smooth muscles
Hyperplasia of mucosal & submucosal vessels
Mucosal edema
Denudation of surface epithelium
Thickening of basement membrane
Eosinophilic infiltrate
Asthma
Chrionic inflammation disease of the airways
Characterized by airflow obtruction
May resolve spontaneously or with treatment
Increased responsiveness of the tracheobronchial tree to a multiplicity of stimuli
Narrowing of airways
Leads to excessive revesible narrowing with consequent reduced airflow and symptomatic wheezing and dyspnea
ASTHMA
