Transcript ASTHMA - RCRMC Family Medicine Residency

ASTHMA
By Dr Aguilera
Definition:
• Chronic inflammatory disorder of the
respiratory airways which includes 3
components
– bronchial hyperresponsiveness to a variety of
stimuli (i.e. allergens, respiratory viruses,
environmental exposures and others)
– reversible airflow obstruction
– associated with recurrent episodes of
respiratory symptoms (i.e. most commonly
wheezing, SOB, chest tightness and cough)
Pathophysiology
• Asthma has 2 mechanisms of reaction:
– Allergen induced bronchoconstriction
• IgE mediated response mast cell stimulation mediators
released
– Other stimuli induced bronchoconstriction
• Inflammatory mediated response inflam cell stimulation
neuro/hormonal reflexes in the lungs
• Both cause edematous swelling of airway
walls hyperresponsiveness and ultimately 
airflow obstruction, which can occur in minutes,
hours, days or weeks
Epidemiology: 2000
• Prevalence is increasing
• 17 million patients with asthma in the US
• Age:
– >18 yrs = 11 million (62%)
– 2-17 yrs = 6 million (38%)
• Race:
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–
–
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8.9
3.5
3.3
1.3
million
million
million
million
Caucasian (52%)
Latino (21%)
African American (19%)
other (8%)
• Gender: Male 42%, Female 58%
Morbidity and Mortality
• Most often associated with failure to appreciate
severity of exacerbation by pt and/or provider:
– Deaths: > 5,000/year but decreasing overall since
1990, probably due to better management from PCP
– Hospitalizations: 466,000 in 2000
• 5% required ICU
• ED Visits:
–
–
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1.9 million in 2000
females 2X > than males
the 11th most common diagnosis
20-30% of these required hospitalization
Morbidity and Mortality Cont’d
• Costs: > $6 billion/year
– average annual cost/pt with attack =$600
compared with $170 with no attack
– cost includes the 3 million lost workdays in
the US per year
• Important Note: Most ED visits, and
therefore, hospitalizations are preventable.
A useful practice is to assume that every
exacerbation is potentially fatal.
Risk factors for death from Asthma
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Past history of sudden, severe exacerbations
Prior intubation
Prior admission to ICU
More than 2 hospitalizations in past year
More than 3 ED visits in the past year
Recent use/withdrawal from systemic steroids
Comorbid conditions
Difficulty perceiving severity of disease (more
common in males)
Asthma Attack Evolution
• Two different pathogenic scenarios involved:
– Airway inflammation predominant:
• pts show a progressive deterioration over 6 hours, days or
weeks (slow onset attack).
• The prevalence is 80-90% in adults and usually assoc with
infectious causes.
• Have a slower therapeutic response
– Bronchospasm predominant:
• Pts present with a sudden onset attack over minutes to 3-6
hrs (asphyxic or hyperacute attack).
• Usually associated with allergens, exercise and stress.
• Have a more rapid and complete response
Diagnosis
• Usually cannot be done in the first visit
• History and Physical exam
– Classic triad
• Cough, SOB and wheeze
• Not all that wheezes is asthma and not all asthma
wheezes.
• Presence of wheezing is a poor predictor of airflow
obstruction, therefore need to use other findings
– Vital signs, RR, mentation, accessory muscle use
Diagnosis Cont’d
• Pulmonary Funtion Testing
– Peak Expiratory Flow Rate (PEFR)
• Measured by age and height
– Spirometry with bronchodilator evaluation
• FEV1, FVC and FEV1/FVC ratio
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> 80% predicted borderline obstruction
60-80% mild obstruction
40-60% moderate obstruction
<40% severe obstruction
• Serial testing over time
– Bronchoprovocation testing with methacholine
• Same deal as with exercixe stress testing in angina
Diagnosis Cont’d
• CXR
– Only on initial evaluation
– Can see flattened diaghrams from hyperinflation
• Blood tests
– none
• Allergy testing
– Allergy skin test
– Blood radioallergosorbent test (RAST)
Classification of Asthma
Stage
Daytime
symptoms
Nighttime
Symptoms
PEFR
of predicted
FEV1
of predicted
Mild
Intermittent
Asthma
< 2x/wk
< 2 nights/wk
>80%
<20%
Mild Persistent
Asthma
> 2x/wk, but
<1x/day
> 2 nights/mo
>80%, but
fluctuates
>20%
20-30%
Moderate
Persistent
Asthma
Daily Sx
> 1 night/wk
60% - 80%
>30%
Severe
Persistent
Asthma
Continual
Frequent
4-7x/wk
< 60%
>30%
Overall Management
• 4 key component to success
– Patient Monitoring
– Controlling Triggers
– Pharmacotherapy
– Patient Education
Overall Management cont’d
• Monitoring
– Peak Expiratory Flow Rate (PEFR) can be used to follow impact
of change in therapy upon lung fxn and/or to assess severity of
attack, NOT to detect presence of airflow obstruction
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Measurement is highly dependent on users technique
Measure with patient standing and should be a evening trial
Record best of 3 tries
Pts should have device at home, however, to establish a baseline
Encouraged to be used at least by pts with mod-severe disease
Mixed data on whether or not home monitoring is beneficial
– For the future:
• Sputum Eosinophilia as a marker for treatment
• Exhaled nitric oxide as a way to predict airway inflammation and
asthmatic control
Overall Management Cont’d
• Controlling Trigger Factors
– Identify and avoid triggers
– They vary from person to person and time to time (for females
most commonly have exacerbations in premenstrual phase)
– Generally fall into 6 categories:
• 1. Allergens (pollen), 2. Irritants (air pollutants), 3. Respiratory
infections (viruses), 4. Physical activity, 5. Chemicals (foods and
drugs) and 6. Emotional stress. These are the main ones identified
clinically
– Allergic rhinitis, chronic sinusitis, polyposis, GERD, menses, and
pregnancy are others that may also contribute to exacerbations
– Once identified: a.) avoid the trigger, b.) limit exposure if cannot
be completely avoided, c.) take an extra dose of bronchodilator
before exposure, but careful with exceeding normal amounts
Overall Management Cont’d
• Pharmacologic Therapy
– This is the mainstay of management in most
patients with asthma, and varies with type
and severity of asthma.
– Relievers
vs.
Controllers
• Fast acting
Slow acting
• Relieve bronchospasm
Controls inflammation
• Stops symptoms
Prevents symptoms
• Take PRN
Take everyday
Overall Management Cont’d
– Mild Intermittent Asthma: (refer to prior slide)
• Includes exercise induced asthma
• Short Acting Inhaled beta-agonists: Albuterol (Proventil, Ventolin)
– Rapid onset of action, get maximal potency of bronchodilation and
minimal side effects.
– Encourage to use 10 minutes prior to exposure to a trigger
– Meter dose inhalers (MDI’s) are now using ozone-safe propellants
instead of chlorofluorocarbon (CFC)
– Alternate delivery forms have been developed
 Albuterol now comes in powder form
 Ipratropium (Atrovent) is NOT a good reliever for asthma
• Mast Cell Stabilizers (Cromolyn, Nedocromil)
– Have no benefit to relieve immediately asthmatic symptoms
– Limited role in adults
Overall Management Cont’d
– Mild Persistent Asthma
• All Persistent asthmatics need a controller
– The assumption behind this recommendation is that regular medication use will
reduce the frequency of symptoms, improve overall quality of life and decrease
the risk of serious attacks and therefore lower the rate of ED visits and
hospitalizations
• Inhaled Steroids
– The gold standard against which all other controlling therapy is compared
– Decreases mast cell and airway inflammation
– Side effects include:
 Local effects (thrush, dysphonia, and bad taste)
 Systemic effects (cataracts, bone loss, increase IOP, growth suppression)
are dose related, rare and occur particularly in prolonged, high dose users
– Using a spacer device is recommended in order to maximize medication delivery
to the lung and minimize oral deposition
– No advantage to using albuterol immediately prior to inhaled steroid to achieve
more lung deposition
– Using an inhaled steroid with a systemic oral steroid is not contraindicated, but
should be limited
Not All Steroids Are Created Equal
Drug
Low dose
Medium dose High dose
Beclomethasone
MDI (Vanceril) 40
mcg
2-6 pfs/day
16-12 pfs/day
>12 pfs/day
Budesonide DPI
(Pulmacort) 200mcg
1-3 pfs/day
3-6 pfs/day
>6 pfs/day
Flunisolide MDI
(Aerobid) 250 mcg
2-4 pfs/day
4-8 pfs/day
>8 pfs/day
Fluticasone DPI
(Flovent)
50mcg
2-6 pfs/day
100 mcg
6-12 pfs/day
250 mcg
>12 pfs/day
Triamcinolone MDI
(Azmacort) 100 mcg
4-10 pfs/day
10-20 pfs/day
>20 pfs/day
Overall Management Cont’d
– Moderate Persistent Asthma
• Incorporates the mild asthmatic receiving treatment, yet remain
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symptomatic
Try to find the combination that works
Long Acting Beta Agonists
– Formoterol (Foradil) and Salmeterol (Serevent)
 Both have similar characteristics, but Foradil has a faster onset of
action (5 min vs 20 min)
 Inhaled meds that have long half lives which allow bid dosing. No
longer in MDI, now in DPI
 Found to be less efficacious than inhaled steroids in improvement
in lung fxn, control of Sx and amt of attacks
 Currently 2nd line after inhaled steroids, and not recom as
monotherapy for mild asthma
 Combo therapy (Advair) with inhaled steroid has shown more
benefit in mod-severe persistent asthma.
Overall Management Cont’d
Leukotriene Receptor Antagonists (LTRA’s)
Zafirlukast (Accolate) – bid dosing
Montelukast (Singulair) – qday dosing and therefore is the
favored one
also approved for allergic rhinitis.
 tolerated well because of low side effect profile
 Approved down to age 2
 Currently positioned 3rd line, after inhaled steroids and
long acting beta agonists.
 Have a varied response among individuals with asthma
 May be used as first line in very mild stage 2 asthma
 May discontinue after 2-3 weeks in “non-responders”

Overall Management Cont’d
– High-dose inhaled steroid
– Fluticasone 100 -250 mcg
– Budesonide 200 mcg
– As the dose of inhaled steroid increases, the likelihood of
systemic absorption and potential for significant side effects
from long term use also increases.
– Therefore, every effort should be made to reduce the dose of
inhaled steroid, seeking to find the lowest dose that continues
to maintain good control and minimize the risk of exacerbations
– Systemic effects are far less frequent than with systemic oral
steroids
– Long-acting beta agonists
– LTRA
Overall Management Cont’d
– Severe Persistent Asthma
• Patients who fail to achieve symptom control despite 2-3 controller
•
medications
Long-acting oral bronchodilator (theophylline)
– Used for its intrinsic anti-inflammatory effect, bronchodilation is considered
secondary
– Increases ciliary motility, mucus clearance and diaphragmatic motility
– Not tolerated well because of Sfx – nausea, cramps, diarrhea, and insomnia
– Narrow therapeutic index requiring check of serum levels
 Toxicity can result in seizures and death
 24 hour preparations are preferred (Uniphyl)
– Currently 4th line, after inhaled steroids, long-acting beta agonists, and LTRA.
• Oral steroids
– Want to avoid as much as possible. If going to use, then use in short spurts or
tapering regimens
Overall Management Cont’d
• Choosing a treatment strategy
Start aggressively then step down
once controlled
Start with a single agent and step
up until control is achieved
Controls symptoms quickly
May take several months to
achieve control
More side effects
Less side effects
Recommended by NIH guidelines for
asthma, expert panel report 2
Requires patience and very close
follow-up
Overall Management Cont’d
• Adjunctive Medications
– Treating comorbid conditions improves asthma
• Antihistamines
– Treating allergic rhinitis decreases responsiveness to triggers
• Nasal steroids
– Have been shown to improve symptoms in patients with both
AR and asthma
– Some studies indicate benefit in asthma alone
• H2 blockers and/or PPI’s
– Prevalence of GERD in asthmatics ranges from 34-80% in
various studies
– Improving reflux has been shown to improve control
Overall Management Cont’d
• Patient Education
– Medication Myths
• Nebulizers offer improved medication delivery and are
referable for more severe asthmatics
– MDI’s used through a spacer can offer more efficient
medication delivery at a fraction of the cost and time when
compared to a nebulizer
• Inhaled steroids increase birth defects or are risky in
pregnancy
– Recent studies have shown no increase in birth defects or
decrease in birth weight with the use of any inhaled steroid
 Category B or C, except Azmacort = D
Overall Management Cont’d
• Asthma flow sheet (blue)
– Found on left side of chart, along with
diabetic flow sheet
– Convenient tracking of symptoms, peak flows
– There is a cheat sheet on bottom of page for
staging
– Can write on progress note: “see blue asthma
flow sheet”
Overall Management Cont’d
• The Asthma Action Plan
– Helps patients and families understand
complex regimen
– The Green Zone (PEFR > 80% predicted)
• What to do on normal days
– The Yellow Zone (PEFR 50-80% predicted)
• Caution
– The Red Zone (PEFR < 50%)
• Danger
The End