Transcript Component 1

Pediatric asthma
Adel Ahadi, MD
• Asthma is a chronic inflammatory condition of the lung airways
resulting in episodic airflow obstruction
• ETIOLOGY.
• Although the cause of childhood asthma has not been
determined, contemporary research implicates a combination of
• environmental exposures
• inherent biological
• genetic vulnerabilities →More than 22 loci on 15 autosomal
chromosomes
• Respiratory exposures in this causal environment include
• inhaled allergens
• respiratory viral infections
• chemical
• biological air pollutants such as environmental tobacco
smoke
• EPIDEMIOLOGY.
• Asthma is a common chronic disease, causing
considerable morbidity→in 2002,
• 8.9 million children (12.2%) had been diagnosed
with asthma in their lifetime
• 4.2 million children (5.8%) had an asthma attack in
the preceding 12 mo, indicative of current disease
• Boys (14% vs 10% girls)
• children in poor families (16% vs 10% not poor)
• childhood asthma is the most common cause of
• childhood emergency department visits
• Hospitalizations
• missed school days
• A disparity in asthma outcomes links high rates of
asthma hospitalization and death with
• poverty, ethnic minorities, and urban living
• Approximately 80% of all asthmatics report
disease onset prior to 6 yr of age.
• Of all young children who experience recurrent
wheezing→only a minority will go on to have
persistent asthma in later childhood.
Early Childhood Risk Factors for Persistent Asthma
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Parental asthma
Allergy
Atopic dermatitis
Allergic rhinitis
Food allergy
Inhalant allergen sensitization
Food allergen sensitization
Severe lower respiratory tract infection
Pneumonia
Bronchiolitis requiring hospitalization
Wheezing apart from colds
Male gender
Low birthweight
Asthma Predictive Index for Children
• MAJOR CRITERIA
• Parent asthma
• Inhalant allergen sensitization
• Eczema
• MINOR CRITERIA
• Allergic rhinitis
• Wheezing apart from colds
• Eosinophils ≥ 4%
• Food allergen sensitization
 Types of Childhood Asthma.
 Asthma is considered to be a common clinical presentation
of intermittent, recurrent wheezing and/or coughing
 There are 2 main types of childhood asthma:
 (1) recurrent wheezing in early childhood, primarily
triggered by common viral infections of the respiratory
tract
 (2) chronic asthma associated with allergy that persists
into later childhood and often adulthood.
 A 3rd type of childhood asthma typically emerges in
females who develop obesity and early-onset puberty (by
11 yr of age)
 Triad asthma, characteristically associated with
 hyperplastic sinusitis
 nasal polyposis
 hypersensitivity to aspirin and non-steroidal antiinflammatory medications (ibuprofen
 The most common persistent form of childhood asthma is
that associated with allergy
PATHOGENESIS
as well as
airways edema
basement membrane
thickening
subepithelial collagen
deposition
smooth muscle
mucous gland
hypertrophy, and mucus
hypersecretion
—all processes that
contribute to airflow
obstruction
Asthma Triggers
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Common viral infections of the
respiratory tract
Aeroallergens in sensitized
asthmatics
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Animal dander
Indoor allergens
• Dust mites
• Cockroaches
• Molds
Seasonal aeroallergens
• Pollens (trees, grasses,
weeds)
• Seasonal molds
Environmental tobacco smoke
Air pollutants
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Ozone
Sulfur dioxide
Particulate matter
Dust
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Strong or noxious odors or fumes
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Occupational exposures
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hairsprays
Cleaning agents
Farm and barn exposures
Formaldehydes, cedar, paint fumes
Cold air, dry air
Exercise
Crying, laughter, hyperventilation
Co-morbid conditions
• Rhinitis
• Sinusitis
• Gastroesophageal reflux
• CLINICAL MANIFESTATIONS AND DIAGNOSIS.
• the most common chronic symptoms are of asthma
• expiratory wheezing
• Intermittent dry coughing
• nonfocal chest “pain
• Older children and adults will report associated
• shortness of breath
• chest tightness
• Respiratory symptoms can be worse at night
• Daytime symptoms→physical activities or play
• asthma symptoms in children can be subtle and nonspecific,
including
• self-imposed limitation of physical activities
• general fatigue (possibly due to sleep disturbance)
• difficulty keeping up with peers in physical activities
• The presence of risk factors, such as
• a history of other allergic conditions
• allergic rhinitis
• allergic conjunctivitis
• atopic dermatitis
• food allergies
• parental asthma
• symptoms apart from colds, supports the diagnosis of
asthma.
• The chest examination is often normal.
• Deeper breaths
• In clinic, quick resolution (within 10 min)
• Decreased breath sounds in some of the lung fields, commonly
the right lower posterior lobe→regional hypoventilation
• Crackles (or rales) and rhonchi
• The combination of segmental crackles and poor breath→
atelectasis
Differential Diagnosis of Childhood Asthma
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UPPER RESPIRATORY TRACT CONDITIONS
• Allergic rhinitis
• Chronic rhinitis
• Sinusitis
• Adenoidal or tonsillar hypertrophy Nasal foreign body
MIDDLE RESPIRATORY TRACT CONDITIONS
• Laryngotracheobronchitis (e.g., pertussis)
• Laryngeal web, cyst, or stenosis
• Vocal cord dysfunction
• Tracheoesophageal fistula
• Vascular ring
• Foreign body aspiration
LOWER RESPIRATORY TRACT CONDITIONS
• Bronchopulmonary dysplasia (chronic lung disease of preterm
infants)
• Viral bronchiolitis
• Gastroesophageal reflux
• Causes of bronchiectasis→Cystic fibrosis Immune deficiency
• In early life, chronic coughing and wheezing can indicate
• recurrent aspiration
• Tracheobronchomalacia
• a congenital anatomic abnormality of the airways
• foreign body aspiration
• cystic fibrosis
• bronchopulmonary dysplasia
• In older children and adolescents,
• vocal cord dysfunction (VCD) can present as intermittent daytime
wheezing
• the vocal cords close inappropriately, during inspiration and
sometimes exhalation
• producing shortness of breath
• Coughing
• throat tightness
• often audible laryngeal wheezing and/or stridor
• spirometric lung function
• Speech therapy is the treatment of choice for VCD.
• LABORATORY FINDINGS.
• Lung function tests can help to confirm the diagnosis of
asthma and determine disease severity.
• Pulmonary Function Testing
• Forced expiratory airflow measures are helpful
• in diagnosing
• monitoring asthma
• in assessing efficacy of therapy
• Spirometry is helpful as an objective measure of airflow
limitation
• usually feasible in children >6 yr of age
• on 3 attempts, the FEV1 (forced expiratory volume in 1
sec) is within 5%, then the highest FEV1 effort of the 3
is used
• Lung Function Abnormalities in Asthma
• Spirometry (in clinic)
• Airflow limitation
• Low FEV1 (relative to percentage of predicted
norms)
• FEV1/FVC ratio <0.80
• Bronchodilator response (to inhaled β-agonist)
• Improvement in FEV1 ≥12% or ≥200 mL
• Exercise challenge→aerobic exertion or running for
6–8 min
• Worsening in FEV1 ≥15%
• Daily peak flow or FEV 1 monitoring: day to day and/or
AM-to-PM variation ≥20%
• Radiology.
• Chest radiographs (posteroanterior and lateral views) in
children with asthma often appear to be normal,
• aside from subtle and nonspecific findings of
hyperinflation
• peribronchial thickening
• Chest radiographs can be helpful in identifying
• abnormalities that are hallmarks of asthma
masqueraders
• aspiration pneumonitis
• hyperlucent lung fields in bronchiolitis obliterans
• complications during asthma exacerbations
• Atelectasis
• Pneumomediastinum
• Pneumothorax
A 4-year-old boy with asthma. Frontal (A) and lateral (B) radiographs show pulmonary
hyperinflation and minimal peribronchial thickening. No asthmatic complication is
apparent.
The Goals of Asthma Therapy: (Asthma
Control)
• Reducing impairment
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prevent chronic and troublesome symptoms
require infrequent use (≤ 2 days a week) of inhaled SABA
for symptoms
• maintain (near) “normal” pulmonary function
• maintain normal activity levels
• meet patients’ and families’ satisfaction with care
• Reducing risk
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prevent recurrent exacerbations of asthma .
prevent progressive loss of lung function
provide optimal pharmacotherapy
The 4 Components of Asthma Management
• Component 1: Measures of Asthma Assessment and Monitoring
• Component 2: Education for a Partnership in Asthma Care
• Component 3: Control of Environmental Factors and Comorbid
Conditions That Affect Asthma
• Component 4: Medications
 Component 1: REGULAR ASSESSMENT AND MONITORING
 Asthma checkups
 Every 2–4 wk until good control is achieved
 2–4 per yr to maintain good control
 Lung function monitoring
 PEF monitoring is feasible in children as young as 4 yr old
 The green zone (80–100% of personal best) indicates good
control
 the yellow zone (50–80%) indicates less than optimal control
 the red zone (<50%) indicates poor control
 Component 2: Control of Environmental Factors and Comorbid Conditions
That Affect Asthma
 Eliminate or reduce problematic environmental exposures
 Treat co-morbid conditions:
 rhinitisdetected in ≈90%
 sinusitis nasal saline irrigations , intranasal corticosteroids,
2–3 wk course of antibiotics
 gastroesophageal reflux incidence of up to 64%8 to 12 wk
 Annual influenza vaccination (unless egg-allergic)
Indoor Asthma triggers include:
Other triggers include:
Secondhand smoke
Pollen and
outdoor molds
Dust Mites
Activity
Pets
Cold and other
infections
Mold
Weather
Cockroaches
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• Component 3: ASTHMA PHARMACOTHERAPY
• Long-term-control vs quick-relief medications
• Classification of asthma severity for anti-inflammatory
pharmacotherapy
• is based on the following parameters:
• (1) frequency of daytime
• (2) nighttime symptoms
• (3) degree of airflow obstruction by spirometry
• (4) PEF variability
• Step-up, step-down approach
• Asthma exacerbation management
• Component 4: PATIENT EDUCATION
• Provide a two-part care plan
• Daily management
• Action plan for asthma exacerbations
Classification of Asthma Severity
CLASSIFICATION
STEP
DAYS WITH
SYMPTOMS
NIGHTS
WITH
SYMPTOMS
Frequent
FOR ADULTS AND CHILDREN AGE > 5 YEARS
WHO CAN USE A SPIROMETER OR PEAK FLOW
METER
FEV1 or PEF % Predicted
Normal
PEF Variability (%)
60≥
30<
Severe persistent
4
Continua
Moderate
persistent
3
Daily
>1/wk
60< - 80>
30<
Mild persistent
2
>2/wk, but
<1 time/day
>2/mo
80 ≥
20-30
Mild intermittent
1
≤2/wk
<2/mo
80 ≥
< 20
• Step 4 Severe persistent
• Symptoms/Night →continual / frequent
• Preferred treatment
• High-dose inhaled corticosteroids
• Long-acting inhaled β2-agonists
• Step 3 Moderate persistent
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Symptoms/Night → daily / > 1night per Wk
• Preferred treatment —
• Low-dose inhaled corticosteroids+long-acting
inhaled β2- agonists
• Medium-dose inhaled corticosteroids.
• Alternative treatment —
• Low-dose inhaled corticosteroids +
• either leukotriene receptor antagonist or
theophylline
• Step 2 Mild persistent
• Symptoms/Night → > 2per Wk < 1 x daily / > 2night per
mo
• Preferred treatment
• Low-dose inhaled corticosteroid (with nebulizer or
MDI with holding chamber with or without face
mask or DPI)
• Alternative treatment
• Cromolyn (nebulizer is preferred or MDI with
holding chamber)
• leukotriene receptor antagonist.
• Step 1 Mild intermittent Quick Relief All Patients
• Symptoms/Night → ≤ 2 days per Wk /≤ 2 nights / mo
• No daily medication needed.
Spacer devices
(1)decrease the
coordination required to
use MDIs, especially in
young children;
(2)improve the delivery of
inhaled drug to the lower
airways
(3)minimize the risk of
propellant-mediated
adverse effects (thrush).
• INHALED CORTICOSTEROIDS (ICS).
• daily ICS therapy as the treatment of choice for all
patients with persistent asthma
• reduce asthma symptoms
• improve lung function
• reduce AHR
• reduce “rescue” medication use
• most important, reduce
• urgent care visits
• Hospitalizations
• prednisone use for asthma exacerbations by
about 50%
Asthma control
Characteristic
Controlled
Partly controlled
Uncontrolled
Daytime symptoms
Twice or less/week
>Twice/week
3 or more
Limitation of
activity
None
Any
Nocturnal
symptoms
None
Any
Need for reliever
Twice or less/week
>Twice/week
Lung function
Normal
<80%predicted
Exacerbation
None
1 or more/year
One in any week
• Asthma Exacerbation Management (Status Asthmaticus)
• RISK ASSESSMENT ON ADMISSION
• Focused history
• Onset of current exacerbation → during sleep (between
midnight ,8 am)
• Frequency and severity of daytime and nighttime symptoms
and activity limitation
• Frequency of rescue bronchodilator use
• Current medications and allergies
• Potential triggers
• History of systemic steroid courses, emergency department
visits, hospitalization, intubation, or life-threatening episodes
• Clinical assessment
• Physical examination findings: vital signs, breathlessness, air
movement, use of accessory muscles, retractions, anxiety
level, alteration in mental status
• Pulse oximetry
• Lung function (defer in patients with moderate
• Risk factors for asthma morbidity and death
• Risk Factors for Asthma Morbidity and Mortality
• BIOLOGIC
• Previous severe asthma exacerbation
• Severe airflow obstruction
• History of rapidly occurring attacks
• Severe airways hyperresponsiveness (AHR)
• Increasing and large diurnal variation in peak flows
• Decreased chemosensitivity and perception of dyspnea
• Poor response to systemic corticosteroid therapy
• Male gender
• Low birthweight
• Nonwhite (especially black) ethnicity
• ENVIRONMENTAL
• Allergen exposure
• Environmental tobacco smoke exposure
• Air pollution exposure
• Urban environment
• ECONOMIC AND PSYCHOSOCIAL
• Poverty
• Crowding
• Mother <20 yr old
• Mother with less than high school education
• Inadequate medical care
• Inaccessible
• Unaffordable
• No regular medical care (only emergent)
• No care sought for chronic asthma symptoms
• Delay in care of asthma exacerbations
• Inadequate hospital care for asthma exacerbation
• Psychopathology in the parent or child
• Family problems
• Alcohol or substance abuse
• Home Management of Asthma Exacerbations.
• A written home action plan can reduce the risk of asthma death by
70%.
• immediate treatment with “rescue” medication (inhaled SABA, up to
3 treatments in 1 hr).
• A good response is characterized by
• resolution of symptoms within 1 hr,
• no further symptoms over the next 4 hr,
• improvement in PEF to at least 80% of personal best.
• The child's physician should be contacted for follow-up
• If bronchodilators are required repeatedly over the next 24–48
hr.
• If the child has an incomplete response to initial treatment with
rescue medication
• a short course of oral corticosteroid therapy (prednisone 1–2
mg/kg/day [not to exceed 60 mg/day] for 4 days)
• Emergency Department Management of Asthma Exacerbations.
• the primary goals of asthma management include
• correction of hypoxemia
• rapid improvement of airflow obstruction
• prevention of progression or recurrence of symptoms.
• Indications of a severe exacerbation include
• breathlessness, dyspnea, retractions, accessory muscle use
• tachypnea or labored breathing cyanosis
• mental status changes
• a silent chest with poor air exchange
• severe airflow limitation (PEF or FEV1 <50% )
• Initial treatment includes
• supplemental oxygen
• inhaled β-agonist every 20 min for 1 hr
• if necessary, systemic corticosteroids given either orally or
intravenously
• Inhaled ipratropium
• An intramuscular injection of epinephrine
• The patient may be discharged to home
• if there is sustained improvement in symptoms
• normal physical findings
• PEF >70% of predicted or personal best
• an oxygen saturation >92% on room air for 4 hr
• Discharge medications include administration of
• an inhaled β-agonist up to every 3–4 hr plus
• a 3–7 day course of an oral corticosteroid
• Management of Asthma During Surgery.
• Patients with asthma are at risk from disease-related complications
from surgery such as
• bronchoconstriction
• asthma exacerbation
• Atelectasis
• impaired coughing
• respiratory infection
• latex exposure
• A systemic corticosteroid course may be indicated for patients
• who are having symptoms
• FEV1 or PEF <80% of the patient's personal best
• who have received more than 2 wk of systemic corticosteroid
• moderate-to-high dose ICS therapy →intraoperative adrenal
insufficiency.
• PROGNOSIS.
• Recurrent coughing and wheezing occurs in 35% of
pre–school-age children.
• Of these, ⅓ continue to have persistent asthma into
later childhood, while ⅔ improve on their own through
the preteen years.
• Asthma severity by the ages of 7–10 yr of age
• Children with moderate to severe asthma and with
lower lung function measures