Asthma Flashcards
Asthma
What is asthma?
inflammatory
variable
reversible
Asthma
age of dx
peak dx before age 5
Asthma
asthma risk factors
age at onset allergen exposure urban residence exposure to air pollution, tobacco smoke recurrent RTI GERD obesity poverty COPD (COPD + asthma = bad)
Asthma
Atopy triad
asthma
allergic rhinitis
atopic eczema
Asthma
Asthma patho (immune cells) early, late & end-stage
Early asthma (immediate):
- Innate + adaptive immune response
- T-helper cells release cytokines to activate B cells
- B cells produce IgE to bind to mast cells
- Mast cells –> histamine and other inflammatory cytokines –> vasodilation, mucosal edema (mucous production & mucous plugs), bronchospasm
- eosinophils release toxic neuropeptides –> bronchospasm
Late asthma (4-8 hours):
- untreated inflammation –> airway remodelling & irreversible damage
- damaged epithelial cells –> impaired muco-ciliary action
- airway obstruction –> air trapping
- hyperventilation –> resp alkalosis
End-Stage
- alkalosis changes to acidosis as airway obstruction/resistance = air trapping = CO2 retention = death
Asthma
4 Q to assess asthma symptom control
ANY nighttime waking
Daytime symptoms > 2/week
SABA > 2/week
Any activity limitation
1-2 = partly controlled 3-4 = uncontrolled
Asthma
Diagnosis in children 1-5
- Persistent symptoms:
- 8+ days/months with symptoms
- 8+ days/month with use of SABA
- 1+ night wakening due to symptoms/month
- Any exercise limitation “their legs should wear out before their lungs”
Asthma
Diagnosis > 6 years of age
FEV1 change >12% after bronchodilator is evidence of reversibility
- negative test does not exclude asthma
- methacholine challenge?
Asthma
Risk/harm of SABA-only therapy
- Regular SABA use reduces bronchodilator response to SABA when needed
- Overuse of SABA (>3 canisters/year) assoc with risk of exacerbation, >12 canisters/year assoc with risk of death
Asthma
Follow-up schedule
- 1-3 months after starting treatment
- Every 3-12 months after (recommend minimum annual
- In pregnancy: q4-6 weeks
- After exacerbation: review within 1 week
Asthma
Spirometry intervals
- At start of treatment
- After 3-6 months for personal best lung function
- Q1-2 years
- PFT most useful indicator of future risk
Asthma
Indications for referral
If pts have been hospitalized for asthma, or have 1-2 exacerbations/year despite step 4/5 treatment (considered difficult to treat asthma)
Asthma
PEAK flow meter monitoring
- BID with best of 3 each time, averaged over 1-2 weeks
- Do before inhalers (expected to be lowest in early morning, highest in afternoon)
Asthma
2021 GINA guidelines Track 1 for Steps 1-2 and 3-5
Step 1-2 PRN ICS-formeterol
Step 3-5 ICS-Formeterol MART
Asthma
2021 GINA guidelines Track 2 (not preferred) for Steps 1 and 2-5
Step 1 PRN ICS w/ SABA
Step 2-5 ICS regularly + SABA PRN
