Asthma Flashcards
What is Asthma according to canadian thoracic society?
“Asthma is an
1) inflammatory disorder of the airways
2)characterized by paroxysmal or persistent symptoms
3)such as dyspnea, chest tightness, wheezing, sputum
production and cough, 4)associated with variable airflow limitation and
5)a variable degree of hyperresponsiveness of airways to endogenous or
exogenous stimuli.”
characteristics of asthma
Characterized by bronchial hyperreactivity
reversible airflow obstruction, usually in response to to an allergen (Type I hypersensitivity reaction)
what are the Anatomic Alterations of the Lungs
-bronchospasm
- excessive production of thick, white bronchial secretion
- mucous plugging ( excessive, tenacious mucous secretion blocks or “plugs” the airway lumen)
- hyperinflation
- In severe cases, atelectasis caused by mucous
plugging
- Bronchial wall inflammation leading to fibrosis
What is the cause of asthma
Genetic susceptibility to allergens, RTI, occupational
and environmental stimuli
trigger leads to
- Airway inflammation
- bronchial hypereactivity
What are Risk Factors for Asthma
Family (parents or siblings) with Hx
Personal Hx of allergic disease
*trigger can impact development at any age
What is extrinscic factor
most frequently caused by an allergy (allergic asthma)
caused by environment or occupation
What is intrinsic factor
no specific cause can be ID
usually no personal or family Hx of atopy/allergy
it is most common later in life
What are some host risk factor for developing asthma?
Genetics Emergency C Section Gender(male↑in childhood) Atopy Hypersensitivity
What are some environmental risk factor for asthma
Indoor/outdoor allergens Air pollution Socio economic status Family size Obesity Hygiene hypothesis
What is Atopy
genetic predisposition of an
individual to produce high quantities of IgE in
response to allergens in the environment . It is a response to allergens in the environment . It is a
condition for the devpt of allergy
What is hygiene hypothesis
: children in a critical stage of
devpt of immune system who are not exposed to
typical infectious agents may more frequently
develop asthma
the relationship between asthma and age group
School Age (6-12 years): atopy is a risk factor
Adolescents (13-18): with endocrine changes
more females develop, causing a shift in the
male to female ratio, decreasing non atopic
Adult: can develop asthma at any age but
What are the peak season of asthma
1) december
2) 3rd wk of school
3) 39 days
4) 52 days
5) a September spikes happens in all age group
how to classify triggers in asthma
inflammatory & non-inflammatory
allergens & irritants
What is the effect of inflammatory trigger ?
- Last longer without tx than non inflammatory
2.May not cause symptoms until hrs/days after
3.Can cause symptoms which may take days to
weeks to resolve
- induce inflammation
how does a trigger cause allergic reaction?
Allergens cause the allergic cascade of events
linked with antigens and production of IgE
- a combination of immune mediators cause inflammation
–>Eosinophils, mast cells, neutrophils, macrophages
releasing histamine & leukotrienes have been
–>cytokines: IL-4, 3,5,13 responsible for
modulating inflammatory and immune cell
What are the non-inflammatory triggers of asthma
- Cold, dry air
2.Weather conditions
3.Physical activity (EIA)
4.Certain Drugs
5.Food additives
6.Hormonal changes
perimenstrual )
What are the inflammatory triggers of asthma
1.Aeroallergens (animals, house dust mites, cockroach, molds & pollens) 2.Viral Infections 3.Occupational sensitizers 4.Second hand smoke 5.Endotoxin
What is the deal with IgE
If you have an allergy, your immune system overreacts to an allergen by producing antibodies called Immunoglobulin E (IgE)
Ige mediates mediates mast cell degranulation
–>release of histamine, prostaglandins, leukotrienes
chemotactic(substance cellular locomotion) factors cause infiltration of neutrophils, eosinophils and lymphocytes
lead to inflammatory response
- ->bronchoconstriction
- ->edema
- ->increase vascular permeasbility
- ->thick secretion
what are the 3 stages of extrinsic allergy responses
Early: within minutes and resolves in an hour
late: several hrs after exposure but lasts
longer. May or many not follow an early
response
*more severe and long lasting
BiPhasic: an early response followed by a late
response
What are the Overall Management of Asthma?
- Confirm the diagnosis & history with PFT’s for
objective measures - Self Management Education
- Determine minimum medication for control
4.Ensure regular reassessment of asthma
control & follow up
Signs & Symptoms of Asthma
- Frequent episodes of breathlessness, chest
tightness, wheezing or cough - Symptoms worse at night and in the early morning
- Symptoms develop with viral respiratory tract
infection, after exercise, or exposure to aero
allergens or irritants - Symptoms develop in young children after playing
or laughing - Symptoms improve with bronchodilators or
corticosteroids
What is the main goal of asthma managment
- Control the disease and symptoms
- Prevent exacerbations and minimize risks for
short and long term complications morbidity
and mortality
control of daytime symptoms
< 4 days/week
control of night time symptoms
<1 night/week
control of physical activity symptom
normal or no symptom at all
control of exacerbation
mild or infrequent
Absence from work or school due
to asthma
should be none
control for Need for a fast
acting β 2 agonist
<4 doses/week
control for FEV
1 or PEF
> 90% personal
best
PEF diurnal variation
should be <10
15%
control for Sputum Eosinophils*
<2
3%
what are the test used in diagnosis and monitoring of asthma
•Spirometry (pre/post Ventolin)
•Peak Expiratory Flow
•Responsiveness to methacholine, histamine or
exercise challenge
•Positive skin tests with allergens or
measurement of specific IgE in serum
•Sputum Induction looking for Eosinophils
What are the 3 pft test that are use for diagnosis asthma
- (preferred): reversible airway obstruction
- Peak expiratory flow variability
- Postive methacholine challenge test
What are the lab result that confirm diagnosis of asthma
Sputum examination
- Eosinophils
- Charcot Leyden crystals
- Casts of mucus from small airways
- Kirschman spirals
- IgE level (elevated in extrinsic asthma)
- Exhaled Nitric Oxide Ξ inflammation
What are the self managment of asthma that should be offer to all patient
–Identify & avoid irritant & allergic triggers
–Assess inhaler technique at each visit
–Written Action Plans
–Adherence to evidence based management
How to control the environment to prevent asthma
goal: aimed at reducing exposure to allergens by:
- remaining inside
- windows closed
- AC on
- Air purifiers & no pets
- no pets
- Dust mites: airtight covers on bed & pillow
- bedroom, chemical agents to kill mites
What is Exercise Induced Bronchospasm
cooling and drying of airways promotes leukotriene
production
What are 3 recommendation in preventing EIA?
- take puffer before exercise
- stay hydrated
- warm up
What can cause occuptional asthma
• wood dust • flour • animal dander (vet clinics) • latex di-isocyanates pine resin
What are some consideration in asthma managment
- All asthmatics should avoid aspirin ; suggest Tylenol use
- patient with pregnancy: 1/3 rd of asthmatics have worse control at this time
- Theophyllines , beta 2 agonists, & steroids can be used
without significant risk of fetal abnormalities - Sinusitis may cause asthma exacerbation
What are included in the pharmacotherapy of asthma
- beta 2 Adrenergic agonists
- Inhaled corticosteriod
- Leukotriene inhibitors
- Anticholinergics
- Anti IgE therapy
- Biologics: Interleukin (IL 5) (anti IL 5)
- Macrolides
what is beta 2 Adrenergic agonists
- rapid, effective bronchodilator
drug of choice
- EIB
- emergency relief of bronchospasm
- use PRN(as needed)
Fxn:
- improve asthma symptoms, not inflammation
what is Corticosteroids
- Most effective medication in treatment of asthma
•Reduces symptoms & mortality (inflammation) - used of inhaled steroids for long term treatment
preferred
What is 1 thing about long term use of oral steriods
- Long term use of oral steroids should be restricted to
patients with asthma refractory to other treatment
What is 1 thing about Short term oral steroid use during exacerbation
reduces severity, duration, & mortality
What is the function of Leukotriene inhibitors
- Leukotrienes mediate inflammation & bronchospasm
- effective in controlling mild to moderate asthma
What is the function of •
Anticholinergics
Can be used as adjunct to first line bronchodilators if there
is inadequate response
–> Tiotropium when added to corticosteroid enhances
asthma control & improve symptoms
What is function of Anti IgE therapy?
Omalizumab (Xolair) is a monoclonal antibody that blocks
IgE biologic effects
–> Indicated in patients with allergic asthma, poorly
controlled with corticosteroids
What is the function of (anti IL 5)
monoclonal antibody administered monthly IV
–> may be effective in tx for asthma
exacerbations in severe eosoinophillic asthma (allergic) for >18yrs
What is the fxn of Macrolides:
- has anti inflammatory and anti-microbial effect
- chronic use in severe astham decrease the frequency of exacerbations because of decrease in IL 8 and neutrophils (anti
What are the reason for poor asthma control
- insufficient patient education
- overuse of beta agonists
- inadequate use of asthma medication
What are the 3 zones in asthma action plan
green zone --> no symptoms yellow zone --> have asthma symptoms red zone --> in danger and need help
What is the Emergency Management of Asthma
- Early & frequent use of aerosolized beta 2 agonists
- High dose parenteral corticosteroids
- Oxygen therapy for hypoxemia
- Antibiotics if evidence of infection
5.In severe ventilatory failure, use MV with
permissive hypercapnia: small VT , low rate, PIP
<50 cm H 2 O to avoid air trapping & barotrauma
What are the physical findsing in emergency asthma
Vital Signs (increased) - Respiratory Rate - Heart Rate (Pulse) - Blood Pressure - Use of accessory muscles of inspiration & expiration - Pursed lip breathing - Increased A P Diameter: barrel chest - Cough & sputum production
What are the physical assessment findsings
- Expiratory prolongation (I:E ratio > 1:3)
- Decreased tactile and vocal fremitus
- Hyper resonant percussion noted
- Diminished breath sounds
- Diminished heart sounds
- Wheezing
What are the 3 radiologiacl findings
- Increased antero posterior diameter
- Translucent (dark) lung fields
- Depressed or flattened diaphragm
What is Status Asthmaticus
a severe condition in which asthma attacks follow one another without pause
Acute , severe and prolonged asthma attack that
may be fatal
–> a unique finding is silent chest
What is the ABG of Status Asthmaticus
Acute Ventilatory Failure with Hypoxemia or (Acute Respiratory Acidosis)
ph:decrease
paco2: increase
hco3: increase slightly
Pao2: decrease
When to intubate acute asthma
•LOC •Exhaustion •Respiratory muscle fatigue/failure •Severe lactic acidosis •Refractory acidemia (pH<7.0) •Inability to oxygenate by mask (SpO 2 < 90%) •Severe cardiac arrhythmias or ischemia