Download Lecture 06. Bronchial asthma

ASTHMA:
MANAGEMENT AND PREVENTION
IN CHILDREN
Lecturer:
prof. Galyna Pavlyshyn
What is Asthma?
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Disease of chronic
inflammatory disorder of
the airways
Characterized by:
– Airway inflammation
– Airflow obstruction
– Airway
hyperresponsiveness
Cookson W. Nature 1999; 402S: B5-11
http://health.allrefer.com/health/asthma-normal-versus-asthmatic-bronchiole.html
DEFINITION OF ASTHMA
•Asthma is a chronic inflammatory disorder
of the airways. The chronic inflammation is
associated with airway hyperresponsiveness;
- airways become obstructed and airflow is limited (by
bronchoconstriction, mucus plugs, increased inflammation)
when they are exposed to various risk factors.
Asthma causes
 recurring episodes of wheezing
 breathlessness
 chest tightness
 coughing
 particularly at night or in the early morning.
DEFINITION
Asthma is a disorder defined by its clinical,
physiological and pathological characteristics
The predominant feature of the clinical history is episodic shortness of
breath, particularly at night, often accompanied by cough. Wheezing defined
on auscultation of the chest is the most common physical finding.
 The main physiological feature of asthma is episodic airway
obstruction characterized by expiratory airflow limitation.
 The dominant pathological feature is airway inflammation, sometimes
associated with airway structural changes.
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Pathophysiology
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Early Acute - these changes cause bronchial hyperresponsiveness and
obstruction. Airway obstruction increases resistance to airflow and decreases
expiratory flow. Impaired expiration causes hyperinflation distal to the
obstruction and increases the work of breathing.
Late Asthma Response occurs in cases of significant allergen exposure.
Recurrence of symptoms appears in 4-12 hours after the initial attack due to
persistent cellular activation. It can be more severe than the initial attack.
Untreated inflammation can cause long term airway damage that is irreversible
(airway remodeling).
What are the Triggering
Factors?
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Domestic dust
mites
Animal with fur
Air pollution
Cockroaches
Pollen
Tobacco smoke
Occupational
irritants
Triggering Factors
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Respiratory (viral)
infections
Chemical irritants
Strong emotional
expressions
Drugs ( aspirin,
beta blockers)
Potential Risk Factors
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Host factors
– Genetic predisposition
– Atopy
– Airway hyperresponsiveness
– Gender
– Race/Ethnicity
Environmental factors
– Indoor allergens
– Outdoor allergens
– Occupational sensitizer
1Masoli
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M, et al. The Global Burden of Asthma:
Executive Summary of the GINA Dissemination
Committee Report. Allergy 2004; 59: 469-78.
Environmental factors
– Tobacco smoke
– Air pollution
– Respiratory infections
– Socioeconomic status
– Family size
– Diet and drugs
– Obesity
DIAGNOSING ASTHMA - Not Easy
CLINICAL DIAGNOSIS
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Clinical diagnosis supported by the certain
historical, physical and laboratory findings
– History of episodic symptoms of airflow obstruction
(breathlessness, wheezing, chest tightness and
COUGH)-response to therapy!
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Episodic symptoms after an
incidental allergen exposure;
Seasonal variability of symptoms;
Positive family history of asthma
and atopic disease.
DIAGNOSING ASTHMA
Consider asthma if any of the
following
signs or symptoms are present:
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Frequent episodes of wheezing –
more than once a month
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Activity-induced cough or wheeze
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Cough particularly at night during
periods without viral infections
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Absence of seasonal variation in
wheeze
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Symptoms that persist after age 3
 The child’s colds repeatedly “go to
the chest” or take more than 10
days to clear up
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Symptoms improve when asthma
medication is given
DIAGNOSING ASTHMA
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Symptoms occur or worsen in the
presence of:
• Animals with fur
• Aerosol chemicals
• Changes in temperature
• Domestic dust mites
• Drugs (aspirin, beta blockers)
• Exercise
• Pollen
• Respiratory (viral) infections
• Smoke
• Strong emotional expression
DIAGNOSING ASTHMA
Dyspnea, airflow limitation (wheeze),
hyperinflation are more likely to be present if
patients are examined during symptomatic
periods.
 Physical signs reflecting severity: cyanosis,
drowsiness, difficulty speaking, tachycardia,
hyperinflated chest,
use of accessory muscles,
and intercostal recession.
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DIAGNOSING ASTHMA
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Physical examination
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Respiratory rate;
Work of breathing;
Aeration
Degree of wheezing
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Suppotive data:
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Pulse oximetry (oxygen saturation);
PEFR – peak expiratory flow rate
Chest radiograph;
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Measurements of lung function
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Spirometry is the preferred
method of measuring airflow
limitation and its reversibility to
establish a diagnosis of
asthma.
Forced expiratory volume
in 1 second (FEV1) - an
increase in FEV1 of ≥ 12% (or
≥ 200 ml) after administration
of a bronchodilator indicates
reversible airflow limitation
consistent with asthma.
The Peak Flow
Meter
Note Peak Flow Numbers
Diary cards to record
symptoms and PEF (in
children older than 5 years)
• Keeping a peak flow diary
will help you predict and
prevent asthma attacks
• Record peak flow numbers
daily, every morning before
taking control medicine(s)
• Watch for trends in
symptoms
Classification of Asthma
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Mild Intermittent Asthma
Symptoms less than once a week
Brief exacerbations
Nocturnal symptoms not more than twice
a month
FEV1 or PEF ≥ 80% predicted
PEF or FEV1 variability < 20%
Traditionally, the
degree of symptoms,
airflow limitation,
and lung function
variability have
allowed asthma to
Mild Persistent Asthma
Symptoms more than once a week but lessbe classified by
than once a day
severity
Exacerbations may affect activity and
(Intermittent,
sleep
Nocturnal symptoms more than twice a Mild Persistent,
month
Moderate Persistent,
FEV1 or PEF ≥ 80% predicted
Severe Persistent)
PEF or FEV1 variability < 20 – 30%
Classification of Asthma
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Moderate Persistent Asthma
Symptoms daily
Exacerbations may affect activity and sleep
Nocturnal symptoms more than once a week
Daily use of inhaled SABA (short-acting 2agonist)
• FEV1 or PEF 60-80% predicted
• PEF or FEV1 variability > 30%
Severe Persistent Asthma
Symptoms daily
Frequent exacerbations
Frequent nocturnal asthma symptoms
Limitation of physical activities
• FEV1 or PEF ≤ 60% predicted
• PEF or FEV1 variability > 30%
Severity of Asthma Exacerbations
Mild
Talks in sentences
Breathlessness
walking
Normal mental
status
Mild tachypnea
End expiratory
wheeze
Good aeration
Oxygen saturation
> 95 %
PEFR > 70%
Moderate
Severe
Talks in phrases
Breathlessness with
talking/feeding
Mildly anxious
Talks in single words
Breathlessness in rest
Moderate tachypnea
Loud expiratory
wheeze
Fair aeration
Oxygen saturation
90-95 %
PEFR = 40-69 %
Severe tachypnea
Inspiratory and
expiratory wheezing
Poor aeration
Oxygen saturation
< 90 %
PEFR < 40%
Anxious
TREATMENT
Asthma Medications
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Bronchodilators
(Sympathomimetics)
Bronchodilators
(Anticholinergics)
Inhaled Corticosteroids
Biologic Response Modifiers
(Monoclonal Antibodies)
Leukotriene Receptor
Antagonists
Mast Cell Stabilizers
Methylxanthene Derivatives
TREATMENT
MILD ASTHMA
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Frequent SABA are the
standard of care
Use of NEB or MDI-S are
each reasonable
Most will require just 1-2
treatment
Those who are SABA
unresponsive may benefit
from systemic
corticosteroids
Most will be discharged
home
Management Moderate Asthma
Albuterol NEB or MDI-S
Prednisone 2 mg/kg/d IM or NEB
 Atrovent
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No improvement
Marked improvement
Slight improvement
Hospitalize
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Continue albuterol
every 30-45 min
Disposition
Discharge home
Management Severe Asthma
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Monitor pulse, RR, oxygen saturation
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Supplemental oxygen
0.15mg/kg Albuterol by nebulization
Atrovent
Good response
Continue with approach to
moderate asthma
Poor response
Terbutaline or epinephrine IM
Methylprednisolone 1-2 mg/kg IV
Albuterol |NEB
50-75 mg/kg IV Magnesii sulfate
Acute severe asthmatic
episode (status asthmaticus)
– Treatment goals are the following:
 Correction of significant hypoxemia with supplemental
oxygen: In severe cases, alveolar hypoventilation requires
mechanically assisted ventilation.
 Rapid reversal of airflow obstruction by using repeated or
continuous administration of an inhaled beta2-agonist;
 Early administration of systemic corticosteroids ( oral
prednisone or intravenous methylprednisolone) is suggested
in children with asthma that fails to respond promptly and
completely to inhaled beta2-agonists.
 Reduction in the likelihood of recurrence of severe airflow
obstruction by intensifying therapy: Often, a short course of
systemic corticosteroids is helpful.
Asthma attacks require prompt
treatment
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Oxygen is given at health centers or
hospitals if the patient is hypoxemic
Inhaled rapid-acting b2-agonists in
adequate doses are essential
Oral glucocorticosteroids (0.5 to 1
mg of prednisolone/kg or equivalent
during a 24-hour period) introduced
early in the course of a moderate
or severe attack help to reverse the
inflammation and speed recovery.
Methylxanthines are not
recommended if used in addition to
high doses of inhaled 2-agonists.
However, theophylline can be used
if inhaled 2-agonists are not
available.
Controller Medications
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Inhaled corticosteroids - ICS
Systemic corticosteroids - SCS
Leukotriene modifiers
Sodium cromoglycate (cromolyn sodium)
Nedocromil sodium
Methylxanthines
Long-acting inhaled 2-agonists,
Long-acting oral 2-agonists.
Classification of asthma by level of control is more
relevant and useful
Levels of Asthma Control
Characteristic
Controlled (All of
the following)
Partly Controlled - Any
measure present in any week
Uncontrolled
None
One or more/year
Daytime
symptoms
None (twice or
less/week)
More than twice/week
One in any
week
Limitations of
activities
None
Any
Nocturnal symptoms/awakening
None
Any
Need for reliever
/rescue treatment
None (twice or
less/week)
More than twice/week
Exacerbations
Lung function
(PEF or FEV1)
Normal
< 80% predicted or
personal best (if known)
Three or more
features of
partly
controlled
asthma
present in any
Week
Mild persistent asthma
 Long-term control: Anti-inflammatory treatment
in the form of low-dose inhaled corticosteroids or
nonsteroidal agents (cromolyn, nedocromil) is
preferred.
– Some evidence suggests that leukotriene antagonists
may be useful as first-line therapy in children.
Quick relief: Short-acting bronchodilators in the
form of inhaled beta2-agonists (SABA) should be used as
needed for symptom control. Use of short-acting inhaled
beta2-agonists on a daily basis or increasing use indicates
the need for additional long-term therapy.
Moderate persistent asthma
– Long-term control:
Daily anti-inflammatory treatment in the form of inhaled
corticosteroids (medium dose) is preferred. Otherwise, low- or
medium-dose inhaled corticosteroids combined with a longacting bronchodilator or leukotriene antagonist can be used,
especially for the control of nocturnal or exercise-induced
asthmatic symptoms.
– Quick relief:
Short-acting bronchodilators in the form of inhaled beta2agonists (SABA) should be used as needed for symptom
control. The use of short-acting inhaled beta2-agonists on a
daily basis or increasing use indicates the need for additional
long-term therapy.