Asthma Flashcards
What is the definition of asthma?
Chronic inflammatory lung disease that is associated with cough, dyspnea, and wheezing
What are the three characteristics of asthma? Which has to be found for a diagnosis of asthma?
- symptoms of cough, dyspnea, and wheezing
- Reversible airway narrowing
- Increased airway responsiveness to stimuli
What is the most common chronic childhood disorder in first world countries? What generally happens as these children age?
Asthma
If resolves after adolescence, then does not usually come back
What is the trend of hospitalization and mortality rates secondary to asthma?
Increasing
What ethnicity is more likely to die from asthma?
Blacks
What are the risk factors for developing asthma? (4)
- Atopy
- Indoor allergen exposure
- Rhinitis
- Occupational exposures
What is atopy?
IgE mediated predisposition to developing allergic reactions
What are the four common indoor allergens that can cause asthma?
- House dust mites
- animal proteins
- cockroach antigen
- alternaria mold
Early or late menarche is a risk factor for asthma?
Early
What is the association between smoking and asthma?
Smoking exposure, including prenatally, predisposed to asthma
What is the associated between weight and asthma?
Obesity predisposes to asthma
What is the relation between maternal age and asthma?
Increasing maternal age increases asthma incidence
What is the primary pathological finding associated with asthma?
airway obstruction d/t combination of inflammation and cellular infiltration
True or false: respiratory infections may predispose to asthma
True
True or false: the degree of inflammation of the airways poorly correlates to the degree of asthma
False–correlates well
What are the three identifiable histological findings with asthma?
- Infiltration of the airway with eosinophils
- Upregulated proinflammatory cells
- Alterations in the non-cellular components of the airway wall
What causes the infiltration of eosinophils in the airways of asthmatics?
Mast cell antigen release
What cause the reduced response to medication in asthmatics?
Bronchial wall remodeling
What are the four major inflammatory mediators of asthma?
- Histamine
- Leukotrienes
- Kallikrein
- Platelet activating factor
What are the four components of asthma airway obstruction?
- Inflammation
- Smooth muscles contraction/hypertrophy
- Mucus gland hypersecretion
- Airway remodeling
What are the three major drugs that are asthma triggers?
ASA
NSAIDs
Beta blockers
What causes cold air asthma?
Acute cooling of the airway triggers irritant receptors
What are the three cardinal symptoms of asthma?
Cough
Wheezing
Dyspnea
When is dyspnea especially prominent with asthma?
After exertion or at night
When is cough especially prominent with asthma?
- after exertion
- Breathing cold air
- at night
What causes the exacerbation at night of asthma?
- Lower levels of endogenous circulating corticosteroids
- Increases in histamine
Is the cough with asthma productive?
Not unless infected
Is wheezing diagnostic for asthma?
No
What happens to the intensity of the breath sounds with asthma?
Decreased
How do you diagnose asthma?
Clinical features
c/w obstructive
What are the three major tests to diagnose asthma?
- Bronchoprovocation
- Pre and post bronchodilator spirometry
- Serial peak flow measurements
What is the MOA of methacholine?
Stimulates M3 receptors in the bronchi, causing asthma
What happens to the peak flow rate with asthma?
Decreased
What are the major pitfalls of provocation testing? (2)
- False positive if recent URI
- False negative if on meds
Does bronchial hypersensitivity alone indicate the presence of asthma?
No–sensitive, but not specific finding
What are the three criteria to asses the severity of asthma?
- Days with ssx
- Nocturnal ssx
- Peak flow rates/variability
What patients can be treated with a PRN rapid acting beta agonists only? If this is not true, what must be added to the drug regimen?
Patients with intermittent ssx:
- less than 2 days/week
- less than 2 nocturnal awakening per month
If more than that, then need an anti-inflammatory
What are the goals of care with asthma therapy? (5)
- Freedom from frequent ssx
- minimal need for beta agonists
- Optimize lung fx
- Maintain normal daily activities
- Satisfaction with asthma care
Diurnal variation in peak flows of greater than what percent is considered diagnostic for asthma?
More than 20% on 3 or more days
When are anticholinergics used for treating asthma?
Refractory emergencies
Why are theophylline drugs not used much anymore?
Drug interactions
Narrow therapeutic range
What is the major antibody that can be used to treat asthma? MOA?
Omalizumab–anti IgE
What is the mainstay of treatment for long term asthma?
Inhaled corticosteroids
What is the indication for systemic corticosteroids? What must be done if these patients receive this therapy?
bad asthma, but need to taper
Is there any benefit of using a nebulizer vs an albuterol metered inhaler?
No
When are levo-beta agonists used?
Only if the pt has sensitivites
Why is it inappropriate to use monotherapy of a long acting beta agonist for asthma?
Risk for sudden cardiac death
What is the MOA of ipratropium?
Anticholinergic for asthma (“I pray I can breathe again”)
When should an inhaled steroid be administered to patients with asthma? How should this be administered?
When they have greater than intermittent asthma
Should be used in a stepwise fashion
What are the side effects of inhaled corticosteroids? Are there systemic effects?
Oral thrush, but no systemic effects
When is systemic corticosteroids indicated for asthma? What corticosteroid is usually used?
Acute exacerbations
Prednisolone
When should anti-inflammatories be used with asthma treatment?
More than intermittent asthma (after step 1)
What is the treatment for emergent asthmatic episodes?
- Oxygen
- Neb every 20 minutes
- Ipratropium if severe
Why is hydration important for asthma treatment?
Reduce mucus thickness
What are the two leukotriene blockers used to treat asthma? Which leukotriene receptors do they block?
Zileuton
Zafirlukast
LTD4 receptors
What cells release leukotrienes in asthmatic patients?
Eosinophils
What happens to wheezing with progression of an acute asthma exacerbation?
Gets less loud
How bad is the asthma if there is accessory respiratory muscle use?
Moderate to severe
When does oxygen saturation fall with an asthma exacerbation?
moderate falls a little (low 90s)
Severe falls a lot (below 90%)
What happens to HR as asthma gets worse?
tachycardia to bradycardia when respiratory arrest is imminent
