Definition
Asthma is a chronic inflammatory disease of the
airways that is characterized by bronchial hyperactivity
and variable airway obstruction which results in
recurrent episodes of wheezing, breathlessness, chest
tightness and/or coughing that can vary over time and
in intensity.
Early-Phase Response
•Peaks 30-60 minutes post exposure, subsides 30-90
minutes later
• Characterized primarily by bronchospasm
•Increased mucous secretion, edema formation, and
increased amounts of tenacious sputum
•Patient experiences wheezing, cough, chest tightness,
and dyspnea
Late-Phase Response
•Characterized primarily by inflammation
•Histamine and other mediators set up a self-
sustaining cycle increasing airway reactivity causing
hyper responsiveness to allergens and other stimuli
•Increased airway resistance leads to air trapping in
alveoli and hyperinflation of the lungs
•If airway inflammation is not treated or does not
resolve, may lead to irreversible lung damage
Triggers
• Allergens
Outdoors: trees, shrubs, weeds, grasses, molds,
pollens, air pollution, spores
Indoors: dust, mites, mold, cockroach antigen
• Irritants tobacco smoke, wood smoke, odors, sprays
• Exposure to occupational chemicals
• Exercise
• Cold air
• Changes in weather or temperature
• Colds & infections
Clinical Features
• Coughing and wheezing are the most common
symptoms of childhood Asthma
• Breathlessness, chest tightness or pressure, and
chest pain also are reported
• Poor school performance and fatigue may indicate
sleep deprivation from nocturnal symptoms
Cough
•Nocturnal cough, recurring seasonal cough, or cough
in response to specific exposures
•Although wheezing hallmark of asthma, cough is often
sole presenting complaint
•Most common cause of chronic cough in children
older than 3 years is asthma
Wheeze
•Wheezing is a high-pitched, expiratory sound
produced when air forced through narrow airways
•Asthma wheeze tends to be polyphonic (varied in
pitch)
•When airflow obstruction severe, can appreciate
wheeze with inspiration and expiration.
Other asthma symptoms in children can be
subtle and nonspecific, including self-imposed
limitation of physical activities, general fatigue
(possibly resulting from sleep disturbance), and
difficulty keeping up with peers in physical activities.
Diagnostic Studies
• Detailed history and physical exam
• Chest X-ray
• Peak flow monitoring
• Pulmonary function tests (Age ≥ 6 years)
• ABGs
• Pulse Oximetry
• Allergy testing
• Blood levels of Eosinophils
• Sputum culture and sensitivity
Management
Management of asthma should have the following
components:
(1)assessment and monitoring of disease activity
(2) education to enhance patient and family knowledge
and skills for self-management
(3) Identification and management of precipitating
factors and comorbid conditions that worsen asthma
(4) appropriate selection of medications to address
the patient’s needs.
Case
Abdul hamid is a 7-year-old boy who presents to
an Emergency Department with cough and trouble
breathing typical of his usual asthma exacerbation.
This episode began 2 days ago and has been
accompanied by a runny nose and a low-grade fever
without any other symptoms. Several family members
are also ill with upper respiratory infections. His
mother has been treating him with ventolin by a
nebulizer every 4 hours, but he has become more short
of breath this evening prior to coming to the ED.
Past medical history is notable for asthma since
infancy, with multiple prior hospitalizations. Other
problems on review of systems include eczema and
environmental allergies. Multiple family members also
have asthma. On social history, his mother mentions
that he is in 2nd
class but has missed at least 10 days of
school this year due to his asthma. His only current
medication is salbutamol.
On physical examination he appears in moderate
respiratory distress with suprasternal and intercostal
retractions. His vital signs are
Temp 100°F
Resp Rate 40 BrPM
Heart rate 120 BPM
Pulse oximetery 95% on room air.
Lung exam is notable for diffuse symmetrical wheezes,
a prolonged expiratory phase and diminished aeration.
His nasal mucosa is erythematous with boggy
turbinate and clear mucus. The remainder of the
examination is unremarkable.
Approach
History
The following areas should be covered unless previously recorded:
Acute presenting history
Triggers
Treatment already given and response
Past asthma history
When diagnosed
Previous admissions including to ICU
Known triggers
Interval symptoms
Smoking exposure
Current and past treatment including compliance and devices
Other atopic conditions including food allergies
Family history of atopic conditions
If previously diagnosed
Who currently manages the child’s asthma
Dates of last review & next planned review
Standard history as per any other patient
Past medical history
Family history
Immunizations
Medications and allergies
Psychosocial history
Developmental history
Examination
Key points to be noted include
Degree of respiratory distress
Respiratory rate
Use of accessory muscles and recession
Posture or position
Oxygen saturation if available
Ability to talk in phrases, sentences or words
Ability to feed
Any clinical signs of major atelectasis or pneumothorax
Mental state (alertness and responsiveness)
Heart rate
Pulse oximetery should be performed if available. A
small decrease in oxygen saturations commonly occurs
after initial bronchodilator treatment and should be put
into the context of the child’s clinical condition and
response to treatment. Significant hypoxia is an indicator
of more severe asthma.
Peak flow has little use in acute asthma and
clinical assessment is the best indicator of severity.
Admission Criteria
Bronchodilator requirement more frequently than 3
hourly
Oxygen requirement
Other factors make discharge unsafe (e.g. social
issues, lack of understanding, lack of ability to re-
present if worsens).
Consider admission to HDU/PICU
Signs of critical asthma severity
Requiring continuous nebulizers for >1 hour without
improvement
Requiring Salbutamol more frequently than every 30
minutes after 2 hours
Hypoxia despite maximal oxygen or raised CO2.
Investigations or Tests
1. Spirometery in Children Aged ≥ 6 years
Forced expiratory volume in 1 second
(FEV1)/forced vital capacity (FVC) < 80% with a 12%
improvement in FEV1 after SABA is specific for the diagnosis of
Asthma.
Performing spirometery is an important part of the
diagnostic process to ensure an accurate diagnosis as 30% of
patients with a diagnosis of asthma have been found not to
have asthma when lung function testing was done.
Spirometery is used as part of asthma control
assessment, as patients with poor lung function are at risk for
remodeling despite having well-controlled symptoms.
2. Peak flow monitoring
•Not recommended for diagnosing asthma in children.
•Can be used in patients with an asthma diagnosis who
are poor perceivers of their asthma symptoms, as part
of an asthma management plan.
•Given the variability of normal values, determine a
patient’s personal best peak flow when well to
establish a baseline.
3. Chest x-ray
4. ABGs
Discharge criteria
Patients may be discharged home if:
•Tolerating 3 hours between bronchodilator
doses
•Normal saturations in room air
•Sensible carers and easy access to medical
care in the event of an acute deterioration.
Discharge medications
Salbutamol initially 3-4 hourly with a weaning
plan over the next 3-4 days.
Continue oral Prednisolone to finish 3-5 days
(no need for a weaning dose for courses less
than 5 days).
Inhaler device and spacer technique should
be checked before discharge.
Patient Education
All patients & families should have their level of
asthma knowledge reviewed and appropriate education
given.
• Ensure that the patient device technique is
correct.
• If parents/carers smoke, ensure they are aware
of the importance of a non-smoking environment and
offer information on quitting if possible.
• Patients and families should go home with
written education material including an action and
discharge plan.
• How to take their medication properly (have
patient demonstrate this, not just describe it).
• The difference between a reliever and controller
medication.
• What triggers their asthma and how to avoid
their triggers when appropriate.
• Recommend annual influenza vaccination for the
patient and their family. Asthma patients should also
receive pneumococcal vaccines as appropriate for
their age.
Assessment of Asthma Control
Assess asthma control and risk factors for asthma
attacks at the time of diagnosis, when creating/ modifying
a treatment plan and when monitoring treatment
outcomes.