Asthma Flashcards
cells involved in asthma
mast cells
eosinophils
T lymphocytes
neutrophils
epithelial cells
symptoms of asthma
variable and reversible airflow obstruction
airway wall inflammation
airway hyperreactivity
recurrent episodes of wheezing, breathlessness, chest tightness, and cough, particularly in early mroning hours
colds “go to the chest” or take more than 10 days to clear
current asthma prevalcence is higher among ___
children than adults
boys than girls
women than men
mortality higher among African Americans than Caucasions
risk factors for asthma
bronchial hyperresponsiveness
genetic predisposition
gender
early infections
atopy
exposure to indoor allergens
outdoor pollution
exposure to tobacco smoke
obesity
prematurity
diet
inactivity
characteristics of the inflammatory response in asthma
cellular infiltration
epithelial disruption
mucosal edema
mucus plugging
atopy
the body’s redisposition to develop and antibody called immunoglobulin E (IgE) in response to exposure to environmental allergens
can be measured in the blood
includes allergic rhinitis, asthma, hay fever, and eczema
status asthmaticus
severe, life-threatening asthma attacks
factors that favor the Th2 phenotype
widespread use of antibiotics
Western lifestyle
urban environment
diet
sensitization to house-dust mites and cockroaches
factors favoring the Th1 phenotype
presence of older siblings
early exposure to day care
tuberculosis, measles, or hepatitis A infection
rural environment
Th2 interleukins
IL-13, IL-4, and IL-5
Discuss the pathophysiology of asthma.
epithelial cell disruption
thickening of the basement membrane (type III and IV collagen)
smooth muscle hypertrophy and hyperplasia
increased number of goblet cells
enlarged submucous glands, intraluminal mucus
infiltration of the bronchial mucosa and sbumucosa by eosinophils, Th2 lymphocytes, mast cells, and othe rinflammatory cells
production of cytokines, arachidonic acid metabolites, bradykinins, and other factors
transcription factors for cytokines elevated as well as NF-kB, promoting production of IgE by plasma cells against specific antigens
mast cells react to antigen and release granules including histamine as well as IL-4 and Il-5, which continues the cycle
occupational exposures that can trigger asthma
toluene diisocyanate, flour, wood
airway changes in asthma
epithelial cell disruption
thickening of the subendothelial basement membrane
inflammatory infiltrate throughout the lung
enlarged goblet cells and increased number
hypertrophy of smooth muscle
stages of inflammation and remodeling in asthma
acute response
chronic inflammation
airway remodeling
acute response in asthma
bronchoconstriction
edema
secretions
cough
chronic inflammation in asthma
cell recruitment
epithelial damage
early structural changes
airway remodeling in asthma
cellular proliferation - smooth muscle, mucous
increased matrix protein deposition
basement membrane thickening
angiogenesis
Describe the volume-time curves of spirometry in an asthmatic.
Describe the flow-volume loop of spirometry in an asthmatic.
lower peak expiratory flow rate
Scooped, concave exipiration
Increased static volume, decreased forced volume
What is a hallmark of asthma in terms of lung function?
displays variability
physiology in asthma
expiratory airflow obstruction
inspiratory obstruction minimized by the inverse relationship between lung volume and airway resistance
FEV1 falls mroe than FVC to lower FEV1/FVC
diffusion capacity is normal or slightly increased (angiogenesis -> more blood)
airway hyperreactivity as demonstrated by methacoline provocation - drop more than 20% at low doses
therapeutic approach to asthma
education
environmental control measures
peak expiratory flow monitoring
medications
criteria for intermittent asthma
symptoms < 2 days a week
nighttime awakenings < 2 times a month
short-acting beta2-agonist use < 2 days a week
no interference with noromal activity
normal FEV1 between exacerbations
FEV1 > 80% predicted
FEV1/FVC normal
0-1 exacerbations per year requiring oral systemic corticosteroids
***not fulfilling any one of these criteria makes it a persistent asthma
goals of asthma management
achieve and maintain control of symptoms
maintain normal activity levels, including exercise
maintain pulmonary function as close to normal levels as posssible
prevent asthma exacerbations
avoid adverse effects from asthma medications
prevent asthma mortality
