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LMCC Review Lecture
Pediatric Respiratory Medicine
Joe Reisman MD, FRCP(C), MBA
Pediatric Respirologist
Chief of Pediatrics, CHEO
Professor and Chairman, Department of Pediatrics
Faculty of Medicine, University of Ottawa
Normal Respiratory Rates
Age
Neonates
Infant
1 yr
2 yr
3 yr
Adolescent
Respiratory Rate
(breaths/min)
30-60
20-50
20-40
20-35
15-30
12-18
Asthma Definition
• Asthma is characterized by paroxysmal or
persistent symptoms such as dyspnea, chest
tightness, wheezing, sputum production and
cough associated with variable airflow limitation
and hyperresponsiveness to endogenous or
exogenous stimuli
• Inflammation key to underlying mechanism for
development and persistence of Asthma
“Not All that Wheezes is Asthma”
Differential Diagnosis
• Infections
– Bronchiolitis
– Respiratory viruses
– Pertussis
– Sinusitis
• Inflammatory
– Asthma
– Tuberculosis
– Bronchopulmonary
Dysplasia
– Cystic Fibrosis
“Not All that Wheezes is Asthma”
Differential Diagnosis
• Aspiration
– Gastroesophageal
reflux
– Palatopharyngeal
dyscoordination
– Foreign body
• Congenital
Malformations
– Vascular rings
– Congenital cysts etc.
• Miscellaneous
– Congestive heart
failure
– Vocal chord adduction
– Psychogenic causes
Clinical Features suggestive of an alternative
diagnosis to asthma
History
Symptoms presenting in neonatal period
Requirement of ventilation in newborn period
Wheeze associated with feeding or vomiting
Sudden onset of cough/choking
Steatorrhea
Stridor
Clinical features suggestive of an alternative
diagnosis to asthma
Physical Examination
Failure to thrive
Significant heart murmur
Clubbing
Unilateral signs
Clinical features suggestive of an
alternative diagnosis to asthma
Investigations
No reversibility of airflow obstruction with
bronchodilator
Focal, persistent or atypical radiographic findings
Making the Diagnosis
• History, Physical, Supporting Investigations
• History of recurrent episodes of cough, wheeze,
shortness of breath, chest tightness
• Evidence of Atopy (history, physical, eosinophilia, family
history)
• Evaluate and exclude alternate diagnoses
• Pulmonary function testing (6 years and older)
– FEV1 and response to bronchodilator
Response to Therapeutic Trial
– Short-acting bronchodilators
– Anti-inflammatory agents
Types of Asthma in Young Children
• Early Onset, Transient
– Non-Atopic
– Outgrown in approximately 60% children
• Early Onset, Persistent
– Associated with Atopy
– Personal Atopy
– Family History of Atopy
Guideline Recommendations regarding Diagnosis
• 1. Physicians must obtain appropriate patient and family
history to assist them in recognizing the heterogeneity of
wheezing phenotypes in pre-school aged children (Level
III)
• 2. In children unresponsive to asthma therapy,
physicians must exclude other pathology that might
suggest an alternative diagnosis (Level IV)
• 3. The presence of atopy should be determined
because it is a predictor of persistent asthma (Level III)
Determination of Asthma Severity and Control
• Severity may only be able to be
determined once adequate asthma control
is achieved
• Asthma control should be assessed on a
regular basis (continuity of care)
• Base assessment of control on following
criteria
Criteria for Determining whether Asthma is Controlled
Parameter
Frequency or Value
Daytime Symptoms
< 4 days/week
Night-time Symptoms
<1 night/week
Physical Activity
Normal
Exacerbations
Mild, infrequent
School Absence
None
Beta-2 Agonist need
<4 doses/week
FEV1 or PEF
>90% personal best
PEF diurnal variation
< 10-15%
Therapeutic Goals
• Achieve and maintain acceptable asthma control
• If poor control, identify reasons
– Environment
– Education
– Drug and Dose
– Inhaler technique
– Compliance issues
• Once good control is achieved, gradually reduce
medication to minimum that maintains control, and
reassess over time
General Management of Asthma
• If control is inadequate, reason or reasons should be identified,
maintenance therapy should be modified
• Any new treatment should be considered a therapeutic trial and its
effectiveness should be assessed after 4-6 weeks
• Inhaled corticosteroids should be introduced as initial maintenance
therapy (Level I) even when patient reports symptoms fewer than 3
times per week
• Although less effective than low dose ICSs, (Level I) LTRAs are
alternative if patient can not or will not use ICSs (Level II)
• If control is inadequate on low-dose ICSs, assess reasons for poor
control and consider additional therapy with long-acting B2-agonists
or LTRAs (Level I).
• Severe asthma may require systemic corticosteroids
• Asthma control and maintenance must be assessed regularly
Frequent Reasons for Poor Asthma Control
• Insufficient patient education in terms of what asthma is,
and how it is controlled
• Insufficient use of objective measures of airflow
obstruction (PEF, FEV1), leading to over- or
underestimation of asthma control
• Misunderstanding regarding role and side effects of
medications
• Overuse of B2-agonists
• Insufficient use of anti-inflammatory agents, including
intermittent use, inadequate use, or lack of use
• Inadequate assessment of patient adherence
• Lack of continuity of care
Regularly assess:
Control
Triggers
Compliance
InhalerTechnique
Co-morbidity
Asthma Therapy
Pred
Add-on therapy
Inhaled Corticosteroids
Fast-acting bronchodilator on demand
Environmental control
Education, Written action plan, and Follow-up
Very mild
Mild
Moderate
Moderately
Severe
Severe
First Line Maintenance Therapy
• Physicians should recommend inhaled
corticosteroids (ICSs) as the best option for
anti-inflammatory therapy monotherapy for
childhood asthma (Level I)
• There is insufficient evidence to recommend
leukotriene receptor antagonists (LTRAs) as
first-line monotherapy for childhood asthma
(Level I). For children who can not or will not
use ICSs, LTRAs represent an alternative (Level
II)
ICS Benefits (Budesonide)
• Clinical measures of control strongly
favored Budesonide over Placebo
– Symptoms
– Rescue medication use and
prednisone courses
– Episode-free days
– Hospitalizations and urgent care
– Initiation of beclomethasone or
additional asthma medication
CAMP Study, NEJM Oct 13, 2000
Growth Effects of Budesonide
Budesonide growth effect
• Led to limited, small, and
apparently transient reduction in
growth velocity
• Projected final height by bone
age similar to Placebo
ICS Safety
Other safety issues for Budesonide
• No adverse effect on bone density
• No association with cataracts
• No adverse effect on sexual
maturation
• No adverse effect on psychological
growth
Add-on Therapies
• Long-acting B2-agonists are not recommended
as maintenance monotherapy for asthma (Level
I)
• After reassessment of compliance, control of
environment and diagnosis, if asthma is not
optimally controlled with low doses of ICSs,
therapy should be modified by the addition of a
long-acting B2-agonist (Level I)
• Alternatively, addition of an LTRA or increasing
to a moderate dose of ICS may be considered
(Level1)
Inhalation Devices
• At each contact, health care professionals should work
with patients and their families on inhaler technique
(Level I)
• When prescribing MDIs, physicians should recommend
use of a valved spacer, with mouthpiece when possible,
for all children (Level II)
• Dry powder breath-actuated devices offer a simpler form
of maintenance therapy in children over 5 years of age
(Level IV)
• Children tend to “auto-scale” their inhaled medication
dose and the same dose of maintenance medication can
be used at all ages for all medications (Level IV)
• Physicians, educators and families should be aware that
jet nebulizers are rarely indicated for the treatment of
chronic or acute asthma (Level I)
Prevention Strategies for Asthma
Primary Prevention
• With conflicting data on early life exposure to
pets, no general recommendations can be made
with regard to pets for primary prevention of
allergy and asthma (Level III). Families with biparental atopy should avoid having cats or dogs
in the home (Level II)
• There are conflicting and insufficient data for
physicians to recommend for or against
breastfeeding specifically for the prevention of
asthma (Level III). Due to its many other
benefits, breastfeeding should be recommended
Prevention Strategies for Asthma
Secondary Prevention
• Health care professionals should continue to
recommend the avoidance of tobacco smoke in
the environment (Level IV)
• For patients sensitized to house dust mites,
physicians should encourage appropriate
environmental control (Level V)
• In infants and children who are atopic, but do not
have asthma, data are insufficient for physicians
to recommend other specific preventive
strategies (Level II)
Our Patients and their Parents Still Smoke…..
50% of Children with Asthma are Sensitive to House Dust Mite
Prevention Strategies for Asthma
Tertiary Prevention
• Allergens to which a person is sensitized
should be identified (Level I), and a
systematic program to eliminate, or at
least to substantially reduce, allergen
exposure in sensitized people should be
undertaken (Level II)
EDUCATION
Education and Follow-up
• Asthma control criteria should be assessed at each visit
(Level IV). Measurement of pulmonary function,
preferably by spirometry, should be done regularly (Level
III) in adults and children over 6 years of age
• Socioeconomic and cultural factors should be taken into
account in designing asthma education programs (Level
II).
• School age children may benefit from education
programs separate from their parents
OXYGEN
Asthma Rx
Differential Diagnosis of Croup
• Epiglottitis
• Bacterial Tracheitis
• Foreign Body in Airway or Esophagus
Management of Croup
• Avoid agitation as much as possible
• Mild croup may be managed at home with p.o.
fluids and humidity
• Warn parents croup may be:
• Worse at night
• May clear in cold air outside
Management of Croup cont’d
• Stridor at rest, moderate chest wall retractions,
and an anxious, restless child are all indicators
of moderate to severe disease and signal need
for hospitalization
• Nurse in Oxygen (usually 30-40%)
• If concerned about degree of respiratory failure,
arterial blood gas indicated
Management of Croup cont’d
• Racemic epinephrine 0.5 mL of 2.25% solution
in 3 mL normal saline by inhalation X 1 dose
may provide relief
• Effect may last 30-60 minutes; may repeat q1-2h
• Dexamethasone 0.6 mg/kg (MAX: 12 mg) (PO,
IM, IV) X 1 dose
• A child who has received racemic epinephrine
should be admitted for observation
Management of Croup cont’d
• If there is a question of impending respiratory
failure, obtain arterial blood gases
• A rising respiratory rate correlates well with a
falling PaO2
• Hypercapnea (rising PaCO2) occurs late in
upper respiratory tract obstruction and is a sign
of increasing respiratory failure
Bronchiolitis
•
•
•
•
Affects approximately 50% children < 2 years of age
Peak incidence 6-8 months, winter, spring
RSV accounts for >50% of cases
Parainfluenza type 3, influenza, adenovirus, ?rhinovirus
can also be causes
• Usually viral prodrome with cough, URTI symptoms
• Most often mild disease
• Can affect those with underlying cardiac, lung disease
more severely
Bronchiolitis cont’d
• Wheezing, tachypnea, tachycardia, respiratory distress lasting 5-7
days
• CXray may show hyperinflation, increased peribronchial markings,
areas of atelectasis, linear densities
• NP swab to detect viral etiology (immunofluorescence)
• Oximetry - keep O2 sat > 92% with humidified O2
• Trial of salbutamol or racemic epinephrine
• Admit if persistent tachypnea, respiratory distress, very young
infants, persistent hypoxia
• Antibiotics have no role unless also suspect complicating bacterial
disease
• Consider prophylaxis of those high risk patients (BPD, cardiac
disease etc.) with Palivizumab (monoclonal antibody against RSV)
monthly during RSV season
Management of Pneumonia- Investigations
•
•
•
•
•
•
•
•
CBC, differential count
Blood culture
Sputum for culture (if child is old enough)
Arterial blood gas if respiratory distress
Tuberculin skin test with Candida control
Cold agglutinin titer
Chest X-ray PA and Lat
Diagnostic thoracentesis if significant amount of
pleural fluid
Management of Pneumonia- Treatment
• General supportive care including PO or IV fluids
• O2 as needed
• IV or PO antibiotics appropriate for most likely
etiologic organism or organism cultured
• Admission based on clinical status
• Empyema requires chest tube drainage
• Consider anaerobic coverage if aspiration a
possibility
Pneumonia- Treatment
Pertussis
• Pertussis is an important cause of chronic cough
• The Chinese named Pertussis “the 100 Day
Cough”
• Immunization does not guarantee protection
from Pertussis
• Cough may have classic “inspiratory whoop” in
chronic phase
Chlamydia Pneumonia
Chlamydia Pneumonia
TB remains an important infection!
Measure the induration when performing a
5-TU tuberculin skin test
RDS- Early Changes
BPD- late changes
Case Presentation- Patient L.M.
• 40 day old infant admitted to CHEO January 15 2003,
with 4 day Hx of wheezy illness; RSV +ve
• Hx intermittent cough since 2 weeks of age
• Slow weight gain since birth; B.W. 3640g; weight on
admission 4080g
• Hx of “greasy” stools
• Meconium took about 2 weeks to pass
• Hx of hypo echoic bowel on prenatal ultrasound
• O/E scrawny infant with crackles over left anterior and
lateral chest; wheezes bilaterally
• Sweat Chloride Tests x 2: 82 and 91 mEq/L
Psychosocial Issues
• Both Parents and Patients can present
with a wide array of psychosocial issues
• Coping with a chronic condition
• Compliance Issues
• Adolescence Issues
• Death and Dying Issues
• Issues regarding drug plans and financial
support
Agents Aimed at Altering Properties of CF Mucus
• N-acetylcysteine- no longer used due to bronchial
irritability
• Recombinant Human DNase (dornase alpha)- breaks
down DNA from dead neutrophils; administered as 2.5
mg once daily by aerosol. Studies of sustained
improvement or decreased decline in PFT’s have yielded
mixed results (Ramsey et al, Am Rev Respir Dis, 1993);
(Fuchs et al, NEJM 1994)
• Not an inexpensive therapy