SM_176a: Asthma Flashcards
Asthma is a ______ disease characterized pathologically by chronic airway ______
Asthma is a heterogeneous disease characterized pathologically by chronic airway inflammation
The two hallmarks of asthma are _____ and _____
The two hallmarks of asthma are variability in lung function and reversibility
(variable expiratory airflow limitation, reversible)
Asthma prevalence is higher among
- ____ than ____
- ____ than ____
- ____ than ____
- ____ than ____
Asthma prevalence is higher among
- children than adults
- boys than girls
- women than men
- African Americans than Caucasians
Burden of asthma is greater in _____, _____, and _____
Burden of asthma is greater in low-income populations, minorities, and children living in inner cities
Describe the factors that influence asthma development
- Host factors (predispose individuals to developing asthma): genetic (atopy, airway hyper-responsiveness), gender, obesity
- Environmental factors (influence susceptibility to development of asthma in predisposed individuals, precipitate asthma exacerbations, and/or cause symptoms to persist): indoor allergens, outdoor allergens, occupational sensitizers, tobacco smoke, air pollution, respiratory infections, dust
Atopy is ______
Atopy is the body’s predisposition to develop IgE in response to exposure to environmental allergens
(allergic rhinitis, asthma, hay fever, and eczema)
Asthma is characterized by ____ type inflammation and primarily involves ____ and ____
Asthma is characterized by TH2 type inflammation and primarily involves mast cells and eosinophils
Describe the steps in IgE synthesis related to asthma
- TH2 cells release IL-4, IL-5, and IL-13
- Activate B cells to release IgE
- IgE crosslink on mast cells
- Mast cells become activated and release histamine, leukotrienes, and cytokines
- Early response: bronchospasm, edema, airflow obstruction
- Late response: airway inflammation, airflow obstruction, airway hyperresponsiveness
Asthma is an ______ lung disease
Asthma is an eosinophilic lung disease
Describe the pathophysiology of eosinophil involvement in asthma
- TH2 cells and mast cells release IL-5 (and other cytokines)
- Activate eosinophils
- Eosinophils release cytokines, leukotrienes, and granule proteins
- Airway remodeling: goblet cell hyperplasia, new vessel angiogenesis, smooth muscle cell hypertrophy / hyperplasia, and subepithelial fibrosis
What are the 4 major pathobiological changes that occur in asthma?
Major pathobiological changes in asthma
- Subepithelial fibrosis
- Smooth muscle cell hypertrophy / hyperplasia
- New vessel angiogenesis
- Goblet cell hyperplasia
Which is normal and which is asthma?
Left is normal
Right is asthma
Describe inflammation and remodeling in asthma
- Acute response: bronchoconstriction, edema, secretions, cough
- Chronic inflammation: cell recruitment, epithelial damage, early structural changes
- Airway remodeling: cellular proliferation (smooth muscle hypertrophy, goblet cell hyperplasia), increased matrix protein deposition, basement membrane thickening, angiogenesis
What are the symptoms of asthma?
- Recurrent episodes of wheezing
- Troublesome cough at night
- Cough or wheeze after exercise
- Cough, wheeze, or chest tightness after exposure to airborne allergens or pollutants
- Colds go to the chest or take more than 10 days to clear
How do you establish the diagnosis of asthma?
- Appropriate clinical history: atopic history
- Obstructive physiology on spirometry which improves after a bronchodilator: obstruction may be present sometimes and not others, bronchodilator response may be present sometimes and not others
- Airways hyperreactivity on bronchoprovocation testing: methacholine bronchoprovocation is sensitive but not specific
(clinical diagnosis and objective assessments of symptoms)
Describe the appearance of asthma on spirometry
- Volume-time curves: lower than normal
- Flow-volume: scooped out / concave
FEV1 decreases ____ in asthmatics than healthy people on methacholine bronchoprovacation
FEV1 decreases more in asthmatics than healthy people on methacholine bronchoprovacation
People are classified as having persistent asthma if they have any one of the following criteria: ______, ______, ______, ______, ______, or ______
People are classified as having persistent asthma if they have any one of the following criteria:
- Albuterol use > 2 days / week
- Asthma symptoms > 2 days / week
- Nighttime awakenings > 2 times / month
- Minor limitations of normal activity
- 2 or more exacerbations per year
(symptoms and exacerbations guide severity, not lung function, so can have persistent asthma even if FEV1 > 80%)
The main line asthma controller medication is ______
The main line asthma controller medication is inhaled corticosteroids
(never give inhaled bronchodilator without inhaled corticosteroid)
The most common asthma rescue medication is _____
The most common asthma rescue medication is rapid-acting inhaled beta-2 agonists (albuterol, salbutamol)
Asthma exacerbations are treated with _____ and _____
Asthma exacerbations are treated with repetitive administration of rapid-acting inhaled beta-2 agonist and early introduction of systemic glucorticoids (prednisone, methylprednisone)
(also oxygen supplementation if low O2 due to V/Q mismatch)
(monitor response to treatment with peak flow and spirometry)
