Asthma Flashcards
asthma respi sx
Respiratory symptoms
Wheeze, SOB, chest tightness, cough
asthma risk factors
Host factor
genetics and obesity
Environment factor
1) allergens or pollutants
Indoor allergens (eg dust mites)
Outdoor allergens (eg pollen, fungi)
Occupational sensitizers (eg wood dust, chemicals, plastics, detergents)
Tobacco smoke
Air Pollution
2) infection
Respiratory Infections
3) others
Socioeconomic factors (low SES)
Diet
diagnosis of asthma
Confirm presence of airflow limitation
FEV1/FVC <0.7 = asthma/COPD
Normal adult: 0.75-0.80; FVC 80% in <6s [Child >0.9]
Confirm variation in lung function
Bronchodilator reversibility
(spirometry: before and after)
Adults: ↑ FEV1 >12% and >200ml; children: ↑ FEV1 >12% predicted
Excessive diurnal variability from 1-2wks BD peak expiratory flow (PEF) monitoring
Adult: variability >10%; children: variability >13%
goals of therapy for asthma
Symptom control: to achieve good control of symptoms and maintain normal activity levels
Risk reduction: to minimise future risk of asthma-related mortality, exacerbations, persistent airflow limitation and side effects of treatment
Differential diagnosis for asthma
Dyspnea/SOB
COPD, obesity, cardiac arrest, deconditioning
Cough
Inducible laryngeal obstruction (aka vocal cord dysfunction)
Upper airway cough syndrome (UACS)
GERD, ACEi induced cough
Bronchiectasis
Wheezing
Obesity, COPD, tracheobronchomalacia, inducible laryngeal obstruction
non phx tx
Avoidance of tobacco smoke exposure
Physical activity
Advice about managing exercise-induced bronchoconstriction
Occupational asthma
Ask patients with adult-onset asthma about work history.
Remove sensitizers/allergens as soon as possible.
Avoid medications that may worsen asthma (aspirin, NSAIDs, BB)
Remove dampness or mould in homes
Breathing exercises
Vaccinations for flu, covid
SE of b2 agonist
SE: tremor, headache, tachycardia, palpitations
SE of ICS
local SE: oral candidiasis, dysphonia, irritation
systemic: osteoporosis, adrenal suppression, growth suppression (children), glaucoma, htn, dm, obesity
SE of oral CS
osteo, htn, dm, hpa axis suppression, obesity, cataract, glaucoma, skin thinning, cutaneous striae, easy brusing, muscle weakness.
FTU for asthma
1-3 mths after starting tx, followed by 3-12 months
After exacerbation, review within 1 week (see exacerbation)
step up asthma tx (short term) when and how
increase maintenance ICS dose for 1-2 wks according to WAAP
During triggers/risk factors e.g., viral infections or seasonal allergen exposure.
step up asthma tx (sustained) when and how
step up (at least 2-3 mths) if not well controlled
E.g., lack of response from maintenance LOW dose ICS-LABA and confirmed to not be due to poor adherence/technique and modifiable risk factors (addressed).
step down asthma tx
when and how
good control for 3mths, no respiratory infection, pt not travelling, not pregnant
Decrease ICS dose by 25-50% every 3mths OR remove a medication (eg LABA/ LTRA) from combination with ICS (Do not stop ICS → risk of exacerbation)
exercist induced bronchoconstriction management
Quick relief/preventive:
Take reliever (SABA eg salbutamol OR ICS-formoterol) 5-20 mins before exercise
Prolonged/recurrent exercise
ICS or LTRA (LTRA give 2hrs before exercise)
Asthma steps
step 1: <2 exacerbations per month
step 2: ≥2 exacerbations per month but < 4-5 per week
step 3: ≥4-5 per week OR ≥1 waking due to asthma
step 4: daily symptoms + ≥1 waking due to asthma
step 5: uncontrolled with acute exacerbations
how to write an asthma written action plan
3 ZONES
1) when you are well
- no cough, wheezing, SOB, chest pain
- no night awakening
= regular dose (state max dose for reliever)
- exercise = reliever dose
2) when you experience 3 or more of the following in the past week
- night awakening
- daytime sx >2 / week
- need reliever >2 / week
- activity limited by asthma
= step up dose
= give oCS 40-50mg/day for 5-7 days if not responding after 24h
3) when you have severe SOB, can only speak in short sentences, have a severe attack and frightened
= call 995, go A&E STAT
= reliever STAT
= OCS dose STAT
dose of salbutamol
1-2 puffs (100-200mcg) PRN
if inhaled
dose of prednisolone
acute: 0.5-2mg/kg/day
typically 30mg OM for adults.
dose of LTRA (including the name) + ADR / counselling
montelukast
adults: 10mg ON
SE: headache, nausea
risk of neuropsychiatric events: agitation, depression, suicidal behaviour, insomnia.
dose of LAMA and example
tiotropium
2 puff OD
(Respimat 2.5mcg per puff)
dose and counselling of theophylline
therapeutic range 5-20mg/L
ADR:
GI: n/v
CNS: insomnia, headache, seizures,
Cardio: tachycardia, cardiac flutter
dose of different ICS
beclometasone 50mcg
beclomethasone 250mcg
for beclomethasone standard particle MDI, low (250-500), mid (500-1000), high (>1000)
pulmicort (budesonide 200mcg)
low (1-2puff per day), mid (2-4), high (>4)
when to add steroids during exacerbation
add temporary (1-2 weeks) OCS for severe exacerbations (PEF or FEV <60% of predicted) or patient not responding to treatment after 48hours
no need to taper since 5-7 day regimen.
management of asthma exacerbations in primary care (mild moderate)
primary care:
mild to moderate
- SABA (salbutamol 4-10 puffs every 20min for 1h)
- OCS (x5-7 days) 40-50mg.
- oxygen supplementation, target 93-95%
severe
- transfer to acute care setting
