Asthma Flashcards
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
Are bronchodilators effective in 2yr olds?
what about 1yr olds?
Yes in 2yrs, often not under 12 months.
at what dose do you need to be careful of side effects (incl growth suppression) in kids on corticosteroids?
400mcg or greater. Aim for 100-400mcg.
what is the stepwise mx of asthma in children for mild - mod - severe
mild = prn SABA
mod = PRN SABA + montelukast (2-5yrs 4mg nocte, 6-14yrs 5mg nocte) OR cromolyn OR ICS @ min effective dose (beclomethasone 100-200mcg/day, budesonide 200-400mcg/day)
severe = prn SABA +ICS ( as above), ?LABA with ICS, ADD as needed - theophyline CR (sprinkles) , ipatropium bromide (neb), oral pred
what is considered - mild, mod, severe asthma in children
mild = infrequent & episodic - attacks not severe, more than 6-8 weeks apart
mod = frequent episodic - attacks 1/week, multiple ED visits
XXXXXXXXX
In a child on high does ICS what diet supplements may be useful
calcium supplements
What vitamin and mineral supplements have been shown to have some benefit?
Vitamin C,E and magnesium
What are some Acute causes of wheezing in children
asthma bronchiolitis bronchitis laryngotracheobronchitis bacterial tracheitis foreign body aspiration oesophageal foreign body
What are some Chronic causes of wheezing in children
Structural abnormalities: - vascular compression/rings -tracheo-bronchomalacea - cystic lesions/masses tumours/lymphadenopathy cardiomegaly
Functional Abnormalities - Asthma - GORD - CF - immunodeficiency -Primary Ciliary Dyskinesia - Bronchopulmonary Dysplasia - retained foreign body bronchiolitis obliterans pulmonary oedema vocal cord dysfunction interstitial lung dx
If a child has a first episode of wheeze in the first year of life what are the chances of them developing asthma
50%
True or false - The older a child is when they have their first episode of wheeze the more likely it is due to asthma?
True
If a child has recurrent or persistent wheeze what are the chances that they have asthma?
80%
What other symptoms or illnesses increase the likelihood of asthma in a child
any features of atopy (eczema or hay fever)
positive allergen test
elevated IgE antibodies
any of the above makes the diagnosis a=of asthma to be about 95% likely
what is more effective, regular or PRN SABA dosing
PRN is as good as regular
what percentage of kids with asthma will only require a SABA?
75%
when would you consider adding in an ICS to a mx plan
when >15% reversal seen while well
>3/week SABA use
ASthma interfering with physical activities
severe/life threatening attacks
What long term side effects have been associated with ICS use
cataracts
dcr BMD
glaucoma
1cm growth retardation in children.
What is symbicort? and what do you use it for?
RED
a LABA and ICS - efometerol/Budesonide
Reliever and Maintenance
what is atrovent?
ipatropium bromide - Antimuscarinic
what is sere tide and what do you use it for?
(purple)
LABA and ICS - salmeterol/fluticasone
Just maintenance
What is Bricanyl and what is it used for?
Terbutaline - SABA
What is SIngulair
Montelukast - a leukotriene receptor antagonist
