Download CHILDHOOD ASTHMA

CHILDHOOD
ASTHMA
DR WANG MAY KAY
PAEDIATRIC DEPARTMENT
HOSPITAL SELAYANG
ASTHMA
3 hallmarks:
•reversible airway obstruction
•airway inflammation
•airway hyperresponsiveness
Clinical manifestation of asthma derive primarily from
airway obstruction
What is the cause of asthma?
The inflammation is produced by allergy, viral respiratory
infections and airborne irritants.
Allergic reactions produce both immediate and late phase
(delayed) reactions.
This late phase reaction produces more serious injury and airway
inflammation  irritability or hyperresponsive airway.
Prolonged airway inflammation can cause scarring.
Anatomy of the bronchioles and alveoli
Narrowed and inflammed bronchial tube
in acute asthma
Pathophysiology of asthma
Environmental
factors
Genetic predisposition
Bronchial
inflammation
Bronchial hyperactivity +
trigger factors
Oedema
Bronchoconstriction
Mucus production
Airway narrowing
Symptoms
Signs and Symptoms in children
•Wheeze
•Nocturnal cough
•Exercise induced cough
•Chest tightness and SOB
•In a young child, the discomfort of chest tightness may lead
to unexplained irritability .
•Child with frequent cough / respiratory infections ( pneumonia /
bronchitis) should be evaluated for asthma.
Signs and symptoms in children
• 33% of children have eczema
• 50% have allergic rhinitis + conjunctivitis
• Asthma presents as recurrent wheeze, breathlessness,
cough
• Chronic asthma – chest hyperinflation, pectus carinatum
( piegon chest) ,
• Harrison’s sulci ( permanent groove in the chest wall at
insertion of diaphragm)
Triggering factors
•Exercise
•Infections
•Allergy
•Irritants
•Weather
•Emotions
Exercise
• running can trigger an episode in >80% of children
with asthma
• bronchodilator medications used before exercise can prevent most
of these episodes.
Exceptions: prolonged running especially during cold weather,
allergy season or illness from a “cold”
•
Swimming is the least asthma - provoking form of exercise.
Infections
• Respiratory infections usually trigger severe episodes of asthma
• Bronchodilator medication, good hydration and corticosteroids
are required to control an asthma episode triggered by viral
infections.
• Chronic sinusitis , ear infection and bronchitis can trigger asthma
and this would require antibiotic therapy.
.
Allergy
•during an allergic reaction, chemical mediators are released.This
produces mucosal swelling, excessive mucus secretion and muscle
contraction in the airways. Thus an allergy can provoke an asthma
episode.
•Allergens (house dust, feathers, pollens, milk,soy, egg etc)
•These allergens may produce low - grade reactions which are of no
obvious consequence; however , daily exposure to these allergens
may result in a gradual worsening of asthma
Useful measures to reduce exposure to
house dust mite
• install zippered plastic or vinyl covers
• pillows should be encased in plastic or laundered once a
month
• fluffy stuffed animals and soft furnishings should be
removed
• carpets should be removed from bedrooms
• all bedding should be laundered frequently
• air conditioning is helpful to lower the relative humidity if
patient is allergic to mites or pollen
• vacuuming will remove < 10% of mites
Irritants
• Cigarette smoke, air pollution, strong odour, aerosol spray and paint fumes
irritate the tissues of the lungs and upper airways.
• The reaction (cough, wheeze, runny nose and watery eyes) produced by these
irritants can be identical to those produced by allergens.
• Cigarette smoke is highly irritating and can trigger asthma.
• Irritants must be recognised and avoided.
Weather
• Cold air can trigger asthma
• precaution is necessary to avoid inhalation of cold air.
• A heavy scarf , worn loosely over the nose and mouth , will help to avoid
cold air induced asthma.
• The weather affects outdoor inhalant agents ( pollens ) .
On a windy day more allergens will be scattered in the air, while a heavy
rainfall will wash the air clean of allergens.
Emotions
•emotional stress (anxiety, frustration, anger) can trigger asthma
•emotional responses involve deep rapid breathing which in turn can
trigger asthma
•children with asthma can suffer from severe anxiety during an
episode of suffocation produced by asthma.This can produce
hyperventilation , which further triggers asthma.
•.
Assessment of severity in childhood asthma
Mild
(Infrequent
episodic)
Episodes at least
4-8 weeks apart
Episodes generally
not major
No interval
symptoms apart
from exercise
induced
No abnormal signs
and normal lung
function between
episodes
Moderate
(Frequent episodic)
Severe
(Persistent)
Episodes < 4-8 weeks
Apart
Episodes more
troublesome
More interval
symptoms
Symptoms many to
most days or nights
Acute episodes
< 4-8 weeks apart
Daily or near daily use
of B2 agonist
No abnormal signs
and normal to near
normal lung function
in between episodes
Abnormal lung
function on “average”
day
Assessment of severity of acute asthma
Mild(unlikely to need
admission)
No
Altered
consciousness
Physical exhaustion No
Moderate(may
need admission)
No
Severe(needs
admission)
Yes
No
Yes
Talks in
Sentences
Phrases
Words
Pulsus paradoxicus
Not palpable
May be palpable
Palpable
Central cyanosis
Absent
Absent
Present
Wheeze on
auscultation
Use of accessory
muscles
Sternal retraction
Present
Present
Silent chest
Absent
Moderate
Marked
Absent
Moderate
Marked
Initial PEF
>60%
40-60%
<40%
Oximetry(SaO2)
>93%
91-93%
90% and below
Goals of therapy
•
•
•
•
•
•
•
participation in normal activities
minimal chronic symptoms
minimal absences from school
minimal need for use of beta agonist
elimination of necessity for ED visit/warded
restoration to and maintenance of normal PEF and
minimal adverse effects from medications
Patient and parent
education
•
•
•
•
•
reaching agreement goals
rehearsals
repetition
reinforcement
review
Asthma therapy
• RELIEVER
• PREVENTER / CONTROLLER
Types of drugs used in asthma reliever
• Beta 2 – agonists – salbutamol (ventolin)
•
- terbutaline (bricanyl)
• Ipratropium bromide (atrovent)
Types of drugs used in asthma – preventive
drugs
• Corticosteroids:
• - prednisolone
• - beclomethasone diproprionate (becotide)
• - budesonide (pulmicort/ inflammide)
• - flucatisone propionate (flixotide)
• Theophylline
• Sodium cromoglycate (intal)
• Long acting B 2 agonist – Salmeterol
• Combination – salmeterol/ flucatisone
• Antileukotrienes – montelukast (singular)
Recommendation for different ages
Age (yrs)
< 8 years
> 8 years
MDI +
MDI +
Spacer + Spacer
Aerocham
ber
+
+
+
Dry
powder
inhaler
-
+
Management
Infrequent Episodic ( mild)
- intermittent inhaled beta2 agonists
Frequent Episodic (moderate)
- continue intermittent beta2 agonists
- add inhaled sodium cromoglycate
Management of Childhood
Asthma Con’t
Persistent asthma (severe)
- replace inhaled sodium cromoglycate with
low dose inhaled steroid (<400mcg/day)
- continue intermittent inhaled beta2
agonists
- if still symptomatic, increase to moderate
dose of inhaled steroids (400-800mcg/day)
- if still not controlled, consider adding
theophyllines or long acting beta2 agonists
Management of Childhood
Asthma Con’t
If the child is still symptomatic,
re-evaluate the symptoms and history
- increase to high dose of inhaled
steroids (800-1200mcg/day)
Rationale for prolonged
prophylactic therapy
• acute bronchodilator therapy
unsatisfactory for long term prognosis
• need to treat underlying inflammation
• reduction of bronchial
hyperresponsiveness
• prevention of later development of
irreversible airflow obstruction
Aims of treatment of acute asthma
exacerbations
•
•
•
•
Prevent death
relieve airway obstruction
relieve hypoxaemia
restore patient’s clinical condition and lung
function to normal as soon as possible
• maintain optimal lung function and prevent
early relapse
• plan avoidance of future relapses and
• develop an action plan in case of further
exacerbations.
Management of AEBA
- prop up + O2 ( via face mask/ nasal prong)
--combivent nebuliser ( salbutamol / ipratropium)
-nebulised B2 agonist + ipratropium bromide
-(salbutamol 0.5:3.5 < 1 year, 1:3 > 1 year)
- steroids (oral / IV) : prednisolone 1mg/kg/day
: hydrocortisone 4mg/kg/dose Q6H
-
- continuous observation
Management of AEBA
•
•
•
•
If no response to above,
Start IV salbutamol continuous infusion
Add IV aminophylline
Mechanical ventilation
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