asthma Flashcards
epidemiology in US
MC:
- boys (< 14 years old)
- women in adulthood
- black > white
burden: high economic and personal burden exists for people with asthma
- miss work and school
asthma pathophysiology
- Chronic inflammation of the airways
- Results in hypertrophy and mucus plugging of the bronchioles
-Involves widespread, variable airflow limitation
-reversible: spontaneously or with treatment) - Airway inflammation → disease chronicity → hyper-responsive airway + limited airflow + respiratory symptoms
risk factors for development of asthma
Genetics: Atopy
-Predisposition to develop IgE in response to environmental allergens
-High IgE: more likely to have allergic response
-Parent has asthma
Environmental exposures
Contributing factors
–
non-atopic triggers + onset
Nonallergic: usually develops in age > 35
Non-atopic: infections, viral, air, medicine
-Ozone
-Smoke
-Particulate matter
-Infection
-Some medications
(aspirin, beta blockers, ACE inhibitors)
-Cold, dry air
atopic triggers + onset
Allergic triggers: usually begins in childhood
-House dust mite
-Pollen
-Ragweed
-Cockroach
-Mold
-Pet dander/saliva
-Foods (peanuts, soy, shellfish, milk)
-Natural oils and fragrances
In diagnosing asthma what is important to ask in Medical History?
Symptoms -patterns, frequency, severity
PMH, FAM HX
asthma: physical exam signs + severe asthma signs
Signs:
- Wheezing
- Hyper-expanded thorax (chronic air trapping)
- Nasal secretions, nasal polyps - Derm exam: atopic
dermatitis, eczema → triad!
Severe asthma:
- airflow may be too limited to produce wheezing
-Auscultation:
- GLOBALLY reduced breath sounds with
- PROLONGED expiration
- ABG changes
Asthma: spirometry
Testing of lung function
-Determines presence and extent of airflow obstruction & if reversible
Airflow obstruction
- Reduced FEV1/FVC ratio (< 90% pred)
Reversibility
- Increase of ≥ 12% and 200 ml in FEV1
chest xray- asthma
Chest radiographs: normal
-Hyperinflation common (if active disease)
-may have bronchial wall thickening (edema and muscle wall hypertrophy)
Useful in ruling out other conditions:
-Pneumonia, CHF or complications of asthma (pneumothorax)
asthma control test chart
-its really important you are asking the right questions….asthma is very under appreciated
-many people report being fine and doctors too -> but in reality they are not well controlled
People walking around with asthma overestimate their hindrance on life
classification of asthma control:
based on sx, nighttime awakening, SABA use, interference with daily life, FEV1, number of exacerbations
Well controlled: symptoms < 2 days/week, night time awakening < 2 days/month, no interference w/ normal activity, FEV1 > 80% predicted/personal best, 0-1 exacerbations per year, SABA use < 2 days/week
Not well controlled: symptoms > 2 days/week, night time awakening 1-3x/week, some interference w/ normal activity, FEV1 60-80% predicted, >2 exacerbations per year, SABA use > 2 days/week
Very poorly controlled: symptoms throughout the day, night time awakening >4x/week, normal activity extremely limited, SABA use several times a day, FEV1 <60%, >2 exacerbations per year
stepwise approach for managing asthma
- Step 1: SABA
- Step 2: SABA + low ICS
- Step 3: SABA + low ICS + LABA
- Step 4: SABA + med ICS + LABA
- Step 5: SABA + high ICS + LABA
- ## Step 6: SABA + high ICS + LABA + oral GC
-step 5 + 6: consider omalizumab for pts who have allergies
-when nothings working -> think about biologics
–
Step up - what to check first and step down - when should you do it
Step up if needed and check:
- adherance
- environmental control
- comorbid conditions
Step down if possible (well controlled for at least 3 months)
medications to tx asthma: how to use a spray inhaler
-health care provider should evaluate inhaler technique at each visit
-stand up, breathe out
-as you start to breathe in -> push down on top of inhaler -> keep breathing in slowly
-hold your breathe for 10s
-breath out
-pMDI- hardest to use
-first thing you do when pt is being txed and are uncontrolled -> ask them to use inhaler in front of you -> if they are doing it perfectly….then consider stepping up
–
dry powder inhaler
-need to generate more negative expiratory force for this
-not an issue for asthma but issue with COPD
–
what is PEF?
Peak expiratory flow: L/min
it is the max SPEED a person can exhale something
you use an at home self-monitoring test (i think jennifer has this)
BELOW 200 L/min: severe airflow obstruction
<40% of normal PEF indicates a severe attack!!
A 20% change in PEF values from morning to afternoon or from day to day = uncontrolled asthma
350-550ish are normal
