1
Fifth stage
Pediatric
كتابة الطالب
.د
فارس
13/10/2015
Asthma
General notes:
10-15% of school age children have by asthma.
It is the commonest chronic disease in children.
It is a common cause of hospital admission, emergency admission, absent from school,
doctor visit, and have high risk of death.
Asthma is chronic inflammatory condition of airway lead obstruction of airways due to
hyper-responsiveness to trigger factors (allergens).
The word asthma give bad impression to the parents ((so don’t say asthma)).
Etiology:
It is multifactorial disease:
Genetic, biological, environmental.
Family history of asthma in one or both of parents or any other allergic conditions: allergic
rhinitis, eczema, frequent sneezing, atopy.
Triggers of asthma:
o exercise
o stress
o crying
o laughter
o hyperventilation
o Viral infection: RSV commonest trigger is viral infection.
o inhalant allergens (animal danders, pollens, house dust mites)
o Tobacco smoke
o Cold air dry exposure.
o Air pollutants.
o Strong odors.
o Anxiety.
Conditions worse asthma (precipitate the attack):
o Sinusitis.
o Allergic rhinitis.
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o GERD :which is very common in children & renders the management difficult, the
mechanism explain this as follows:-
1. Recurrent emesis aspiration.
2. Vagally stimulated bronchospasm (reflux).
Pathology:
Inflammation.
Allergic condition IgE and eosinophilis.
Edema.
Thick secretion.
Collagen deposition.
All lead to airway obstruction.
Clinical features:
1. Cough.
2. wheeze (intermittent, inspiratory and expiratory)
3. Dyspnea.
4. Chest tightness.
All the above features are worse at night.
In the day, the symptoms are more in physical activity (exertion).
Clinical exam:
Tachypnea.
Retractions.
Decrease breath sounds.
Inspiratory & expiratory wheeze.
Silent chest
Crackles (because of increased production of secretion due to mucus gland hypertrophy).
Note no clubbing in asthma (but in CF there is clubbing).
In asthma hyperventilation (acidosis) and hypoventilation (alkalosis)
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Signs of severity:
Tachypnea
Tachycardia
Inability to talk
Diaphoresis
Pulsus paradoxus (may be absent)
Tripod position
Altered mental state
Cyanosis
Wheezy chest or silent chest.
Diminished breath sounds.
No air entry or exchange.
Investigations:
Chest X-ray (CXR):
o Is indicated in:
1- First attack to exclude other DDx (no need to repeat CXR in the other attack).
2- If we treating the patient with his good compliance but the patient condition still
NOT stable, perform CXR to diagnose complications or to exclude other Diseases.
o Findings like pneumothorax, atelectasis, mediastinum widening
Peak expiratory flow (PEF):
o Very important but is indicated in children who are 6 years old age or greater,
because it needs cooperation.
o Told to child to blow forcefully and take the highest readings after 3 attempts, and
Compare the results according to AGE, SEX, and ETHINICITY.
o PEF test easy, cheap, done at home.
o FEV1/FVC must be >80% it means good control of asthma.
o If between 60-80 it is fairly controlled.
o If <60% poorly controlled (severe attack).
o FEV1 is important to change the treatment.
Complete blood picture (CBP): eosinophils >4% is heralded for persistent asthma.
Sputum (for eosinophils) not necessary
Blood culture (it is NOT so necessary to be done)
Prick skin test important test for children, any suspected allergens injected SC on
forearm, till development of wheal (positive test).
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Measuring of IgE by RAST test (radio allergo sorbent test).
Electrolyte and blood gases done in severe asthma.
Differential Diagnoses:
GERD.
TEF (H-type).
Foreign body inhalation.
Bronchiolitis.
Interstitial lung disease.
Broncho-pulmonary dysplasia (or mycosis).
Cystic fibrosis (rare).
Treatment of asthma:
1- Checkup asthma every 2-4 weeks until you achieve good control then do checkup 2-4
times per year.
2- Control of triggers precipitating factors and co-morbidity (treat them).
3- Pharmaco-therapy long term control therapy (controller) – quick relief therapy
(reliever or
rescue
).
4- Education of child and parents, action plan, how to take steroid at home, how to use
drugs, house cleaning.
Types of inhalers:
Metered dose inhaler suitable for older children.
Spacer for younger children.
Dry powder inhaler
Nebulizer (the best one but needs electricity).
Long term control therapy (controller):
1- Inhaled corticosteroids:
Examples: beclomethasone, fluticasone, budesonide.
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Good ant-inflammatory agents.
Good in control of acute attacks.
After use of inhaled corticosteroids wash child mouth to get loss side effect like
dysphonia and oropharyngeal candidiasis (for low dose) and systemic steroid side
effects (for high dose).
2- Inhaled long acting B agonist (LABA):
Salmeterol (delayed onset of action) and formoterol (start after 10 min)
Formoterol is better.
Duration of action 12 hours.
Not use in acute attacks.
Give it twice daily.
3- Theophylline:
Old drug, out of use.
Narrow therapeutic window.
Variation of effects.
A lot of side effects (hypotension, seizure).
Use sustained release theophylline.
Has bronchodilator and anti-inflammatory effects.
4- NSAID:
Like cromolyn and sodium nedochrolene and Ental.
2-5 times per day.
No side effects.
5- Leukotrienes antagonists (modifier):
Montelukast above 1 year age.
Zafirlukast above 5 years age.
Ziluten above 10 years age.
All give as chewable tablets (4-5 mg/day) at night.
6- Anti-IgE:
Like Omalizumab.
May produce anaphylaxis.
They are monoclonal antibodies against IgE block IgE binding site.
Is given for those >12yrs old.
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It is expensive and NOT available.
May produce anaphylaxis.
7- Anti-
interleukin 5:
It is monoclonal antibodies.
Like mepolizumab.
Quick relief therapy (reliever or rescue):
1- Short acting B agonist (SABA).
Inhaled Side effects less than oral one.
Side effects like tachycardia, hyperkalemia, tremor.
It is bronchodilator.
Like salbutamol, albuterol.
0.5 ml for less than 5 years // 1 ml for more than 5 years ((only ml, not ml/kg)
Very effective.
Give it with 2 ml of normal saline use nebulizer.
Oral is as effective as parenteral.
2- Systemic steroids:
Used in severe or moderate asthma.
Give short course 3-10 days or 5-7 days.
No need for tapering.
They are the best anti-inflammatory.
You can give corticosteroids for 2 weeks without tapering.
Side effects hypertension, short stature, weight gain, hypokalemia, cataract,
glaucoma, reduced immunity.
Under-utilization of steroids lead to bad prognosis.
3- Inhaled anti-cholinergic:
Like ipratropium bromide.
Used with SABA.
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Stages of asthma:
Mild intermittent:
o Less than 2 days symptoms / week.
o Less than 2 bad nights / month.
o Rescue treatment only, no need for controllers.
Mild persistent:
o More than 2 days symptoms / week.
o More than 2 bad nights / month.
o Rescue treatment + one controller agent (low dose inhaled CS).
Moderate persistent:
o Daily symptoms / week.
o More than 1 bad night / week.
o Rescue treatment + 2 controllers (inhaled CS & theophylline).
Severe persistent:
o Frequent night & days symptoms.
o Rescue treatment + 3 controllers (High dose inhaled CS + LABA +/- systemic steroids).
Prognosis:
Asthma is recurrent disease.
Two third of child treat completely.
One third of child still with adult asthma.
Normal PaCO2 is bad ominous sign that indicates respiratory failure (normal PaCO2
should be<40).
Status asthmaticus:
History of severe attacks.
Low birth weight.
Occur in male gender.
Treatment:
Admission to ICU Monitoring two rescue treatment Inhaled and systemic
corticosteroids aminophylline infusion Mg sulfate (IV 75 mg/kg) ipratropium
bromide terbutaline adrenaline (0.01 mg/kg) SC or IM (very painful) Ventilator.
No need for Oral beta 2 agonist / Ketotifen (anti-histamine) / Antibiotics /Oral
bronchodilators (side effects).