Transcript ASTHMA

ASTHMA
Definition
• Reversible airflow obstruction
+
• Airway hyper-reactivity
Pathology
• Inflammation involving eosinophils
and T lymphocytes
• Release of various mediators and
cytokines
• Initially reversible, spontaneously or
with drugs
• Eventually permanent structural
change results in irreversibility =
remodelling
Remodelling
• Extent varies between patients
• Lung function decline faster than in
non asthmatics
• Early intervention may prevent
decline
Incidence
• 20% of children have asthma
• 6% of adults
• 15% cases are late onset
• Boys . Girls
Statistics
• 5 million people in uk receive
asthma treatment
• NHS treatment costs £850
million/year
• 18 million working days
lost/year
Presentation
• Symptoms
• Cough
• Expiratory wheeze
• Chest tightness
• Dyspnoea
• Nocturnal cough
• Exercise induced wheeze
Diagnosis
• Twice daily PEF recording for 2 weeks
• 15% variation = asthma
• Therapeutic trial of salbutamol
• >15% improvement in PEF after 15-30 mins =
asthma
• 2 week trial inhaled or oral steroid
• 15% improvement in PEF = asthma
Differential diagnosis
• Adults
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Gastro oesophageal reflux
Bronchiectasis
COPD
LVF
PE
Interstial lung disease
Tumour
Differential diagnosis
• Children
• Cystic fibrosis
• Ciliary dyskinesia
• Foreign body inhalation
• Gastro oesophageal reflux
• Bronchiectasis
Diagnosis - Children
• Can’t do PEFR
• Daignosis made on history and
response to treatment
• 30% children wheeze in first 3
years of life
Differential diagnosis
• COPD
Spirometry fev1/fvc < 75%
• LVF
Older, echo lvedp <50%
• PE
• Vocal cord dysfunction
• Psychogenic breathlessness
Triggers
• Infections particularly viral
• Allergens e.g. house dust mite,
pollens, animals.
• Occupations e.g. isocyanate
containing paints, flour
• Environmental pollutants e.g.
cigarette smoke, sulphur
dioxide
Triggers
• Drugs e.g. beta blockers
• Exercise
• Cold air
• Hyperventilation
• Foods
• Psychological factors
Management
• Aims
• Control of symptoms and
exacerabtions
• Minimal lifestyle disturbance
• 40% of asthmatics say their
symptoms affect their lifestyle
Management
• BTS guidelines
• Stepwise approach
Step one
• Mild intermittent asthma
• Short acting inhaled beta agoinst
as required
Step two
• Needing beta agonist every day
• Regular preventer therapy
• Add inhaled steroid 200800micrograms/day
• Start at dose appropriate to
severity of disease
• 400 micrograms for most people
Step 3 add on therapy
• Add inhaled long acting beta
agonist = LABA
• i.e. salmeterol
•
oxis
Poor response
• Stop LABA
• Increase inhaled steroid to
800mcg/day
If still symptomatic
• Consider slow release
theophyline
• Or
• Leukotriene receptor antagonist
Step 4
• Increase inhaled steroids
• Adults 2000mcg/day
• Children 800mcg/day
• Add in 4 th drug
• LTRA
• SRT
• Oral beta agonist
Step 5
• Oral steroids in lowest possible
dose
• Maintain high dose inhaled
steroids
• Refer to respiratory specialist
Short acting beta 2
agonists
• Relievers
• Salbutamol and terbutaline
• Use on prn basis
• Useful before exercise
Short acting beta 2
agonists
• Overuse
• Tachycardia
• Tremor
• hypokalaemia
Inhaled corticosteroids
• Preventers
• Improves symptoms and lung
function
• Might prevent permanent airway
damage
Inhaled corticosteroids
• Beclomethasone, fluticasone
and equally effective
• Fluticasone twice as potent
needs half the dose
• Thrush and dysphonia
decreased by rinsing mouth out
after use abd using a spacer
Inhaled corticosteroids
• High doses associated with
• Cataract formation
• Adrenal suppression
• Slow growth rate in children – no
evidence that final height is
affected
Adrenal suppression
• Presentation
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Fatigue
Weigth loss
Anorexia nausea
Abdo pain
Hypoglycaemia
seizures
LABA
• Salmeterol and eformeterol
• Patients > 5 years
• Relieves symptoms and improves
lung function
• Adding ALBA to inhaled steroids is
more effective than doubling the
dose of steroid
LTRA
• Montelukast and zafirlukast
• Block action of leukotrienes
• Montelukast – add on therapy age
2 years and older
• Zafirlukast – monotherapy or add
on therapy age 12 years and older
LTRA
• Reduce exacerbations
• 5-8% improvement lung function
less than inhaled steroids or
LABA
• 4 week trial continue if
symptoms and lung function
improve
LTRA
• Side effects
• GIT upset
• Headache
• Rash
• Churg strauss syndrome
Theophylline
• Phyllocontin continuus
• Has anti inflammatory actions
• Use at step 3
• Side effects
• GIT
• Arrythmias
• Hypokalaemia
• convulsions
Oral steroids
• Should be under specilaist
review
• Monitor
• BP
• Blood sugar
• Osteoporosis prevention
Delivery systems
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MDI
10% dose reaches lungs
MDI + spacer
Breath actuated inhaler
Dry powder inhaler
• Turbohaler
• Accuhaler
• Clickhaler
Children
• 0-2 yrs
mdi + spacer mask
• 2-5 yrs
mdi + spacer
• > 5 yrs
mdi + spacer, breath
actuated inhaler or dry powder
inhaler
Lifestyle measures
• Avoid precipitating factors
• Housedust mite
• Vacuuming
• Impermable matress covers
• Reduced soft furnishings
Lifestyle measures
• No smoking infamily
• Keep pets out of bedrooms
• Keep weight down
Acute asthma
• Signs of severity
• Children
• Inability to feed
• Use of accessory muscles
• Sub costal recession
• Nasal flaring
Acute asthma
• Signs of severity
• Adults
• Pulse > 110 bpm
• Resp rate > 25/min
• PEF 33-50% max
• Inability to complete sentenes
Life threatening
• Cyanosis
• Silent chest
• Bradycardia
• Hypotension
• Poor resp effort
• PEF < 33% max
Management
• Oxygen
• Nebulised beta 2 agonist
• Salbutamol 5mg
• Atrovent 500mcg
• Halve doses for children
Management
• Short course oral steroids
• Adults
40mg/day
• Children > 5
30mg/day 3 days
• Children 2-5
20mg/day 3 days
• Children < 2
10mg/day 3 days