Asthma Flashcards
(45 cards)
What is Asthma (broad definition of symptoms)
Chronic Inflammatory disorder of the airways, causing recurrent episodes of wheezing, breathlessness, chest tightness and coughing. With hyper-responsiveness of the airways.
Symptoms are worse at night or the early hours of the morning with widespread but variable airflow obstruction - reversible either spontaneously or with treatment.
What is Asthma (histopathologically)
- infiltration of the mucosa (inner lining of the airways) with inflammatory cells (esp. eosinophils)
- oedema of the mucosa, thickening of the basement membrane.
- damaged mucosal epithelium
- hypertrophy of the mucus glands with increased mucus secretion
- smooth m.m constriction
Asthma stats
- age of onset
- prognosis
- common presentations
- incidence in - childhood and adulthood.
- normally between 2-7yrs (but any age)
- most children ‘grow out of it’ by puberty
- often presents with cough ( post exercise, early morning, disturbed sleep)
1 in 4-5 children (mild), 1 in 8 adults has or had asthma
what is the focus in asthma management
PREVENTION - asthma attack = failed treatment
What are some key triggers for asthma attack
NB - how common is dust mite allergy in atopic asthmatics
ABCDEFGHIJ
A - Allergens (pollens, moulds, dander, mites)
B - Bronchial infections
C- cold air, exercise
D - Drugs - aspirin, NSAIDS (20%), b-Blockers
E - Emotion (laughter, stresss), Exercise
F - Food (seafood, nuts, MSG, sodium metabisulphate)
G - GORD
H - Hormones (pregnancy, Menses)
I - irritants (smoke, perfume, smells)
J - Job (wood dust, flour dust, isocyanates, animals)
NB 90% of kids with atopy (with asthma) are skin prick + to dust mite extract.
Clinical Symptoms of Asthma
NB - what presentations should you be suspicious of.
- Wheeze
- coughing (esp at night)
- chest tightness
- breathlessness
NB suspect in any child with recurrent nocturnal cough and in those with intermittent dyspnoea or chest tightness (esp after exercise)
Clinical findings in Asthma
- diffuse, high pitched wheeze throughout inspiration and part of expiration.
- prolonged expiration.
If wheeze absent on normal beathing may appear with forced expiration
BUT absent wheeze in breathless person is serious sign.
WHEEZE DOES NOT = ASTHMA
How to investigate asthma (and results that indicate it)
- Peak flow measurement - variations in values at different times
- spirometry = 6yr olds
- Measurement of above before & after bronchodilators = >15% FEV1 and PEFR improvement
- airway reactivity test - rarely done
- mannitol inhalation test
- Allergy testing
Reasons for suboptimal asthma control
- poor compliance
- inefficient use of device
- lack of preventer medication
- using bronchodilators alone
What is good control in asthma
no cough, wheeze, breathlessness most of the time - no nocturnal waking due to asthma no limitation of normal activity good exercise ability minimal need for ventolin no severe attacks no side effects from medication near normal lung fn - >80% predicted
What are the 6 steps in an asthma mx plan
1) Assess the severity - when stable - (intermittent/episodic, mild persistent, moderate persistent. severe persistent)
2) achieve best lung fn - monitor with regular spirometry
3) avoid triggers
4) maintain best lung fn
5) develop an individual plan - needs to recognise deterioration, knows when to initiate medication, knows when to seek help
6) educate and review regularly
Drugs to treat asthma
1) reliever - Bronchodilator ( B2 agonist - salbutamol, terbutaline (bricanyl) adrenaline - erol, anticholinergics -ipatropium bromide (atrovent), methylxanthines - theohpyline (brondecon))
2) preventer - antiinflammatory (steroids (inh/oral) mast cell stabilisers - cromolyns (cormoglycate & nedocromil), leucotriene antagonists (monteleukast)
3) symptom controller - long acting B2 agonist
When to use a preventer
if asthma episodes are >3/week or using SABA > 3/week
>1 canister/3months
evidence of reversible airflow when asymptomatic
interfering with exercise despite pre-treatment
asthma attacks every 6-8 weeks
or infrequent but severe - life threatening
when using corticosteroid inhalers what do you need to watch out for?
oral thrush
hoarse voice (dysphonea)
bronchial irritation - cough
adrenal suppression - possible at doses >800mcg daily, likely at doses of 2000mcg
what 2 options are there for fixed dose combination asthma medications?
inhaled corticosteroids with LABA
1) Seretide - fluticasone + salmeterol (LABA) - MDI or Accuhaler
2) symbicort - budesonide + formeterol - turbuhaler or MDI
prophylactic treatment options
LABA 5 minutes before lasts 1-2hrs
mast cell stabilisers (MCS) - sodium cromoglycate (SCG)/ nedocromil - 2 puffs
SCG + B2 agonist 5-20mins prior
montelukast 10mg daily or 1-2hrs prior
what is low dose Inhaled corticoid steroid
<160ngs ciclesonide
what is high doe ICS
> 400mcg beclomethasone
800mcg budesonide
500mcg fkuticasone
320mcg ciclesonnide
What dose of prednisolone would you consider for an exacerbation?
1mg/kg/day for 1-2 weeks
What is a basic Mx plan for asthma (adults)
PRN B2 -Agonist
then:
ICS + PRN B2 -Agonist (with Prophylactic cromolyn or B2 agonist)
then:
Med-high dose ICS + LABA or theophyline or leukotriene (oral pred for exacerbations)
signs of a severe asthma attach
exhaustion drowsiness/confusion silent chest quite wheeze cyanosis chest retraction
RR >25 adults, >5o children
PR >120bpm
peak flow <90%
What is the 4x4x4 rule
4 puffs, with 4 breaths after each puff, every 4 minutes - ambulance called after 2nd round if no improvement
What is the guidelines for treating a severe asthma attack with spacer in 35kg
Every 20min for the first hour give:
35kg 12 puffs, 4 puffs
ipatropium not needed in moderate attack.
how to treat the acute severe attack (adult)
Continuous neb salbut + ipatrop
IV salbut (500mcg)
steroids - pred 50mg or hydrocort 250mg IV/IM Q6hrly
o2 8l/min face mask - maintain sat >95%
if ?cardioresp arrest
adrenaline 0.5mg 1:1000SC/IM or 1:10,000 IV
MgPO4 25-100mg/kg (max 2gm) IV over 20min
