bronchiolitis in paediatrics
TRANSCRIPT
Bronchiolitis in Paediatrics
Prepared bymalek ahmad
University of malaya
Introduction Acute infectious inflammatory disease of the URT and LRT that result in obstruction of the small airways
Occur in all age gp, larger airways of older children and adults better accommodate mucosal edema, severe respiratory symptoms limited to young infants
90% are aged 1-9 months (rare after 1 year of age), boys affected more than girls
Major concern not only the acute effects bronchiolitis but the possible development of chronic airway hyperreactivity (asthma)
Infants a affected most often because of their small airways, high closing volumes, and insufficient collateral ventilation
Aetiological agents
• Isolated agent in 75% of children younger than 2 years and highly contagious• Enveloped RNA virus that belongs to the Paramyxoviridae family within the
Pneumovirus genus• Two RSV subtypes A (severe) and B (structural variations in the G protein)• Viral shedding in nasal secretions for 6-21 days after symptoms develop. IP
=2-5 days• Complex immunologic mechanisms play a role in RSV bronchiolitis. Type I
allergic reactions mediated by the IgE antibody account for significant bronchiolitis thus breastfed babies (colostrum-IgA) relatively protected
Respiratory Syncytial Virus (RSV)
Human metapneumovirus, parainfleunze, influenza, rhinovirus, adenovirus
• accounts for 5-15% particularly among older children and adults
Mycoplasma pneumoniae
Risk factors
Low birth weight (PREM)
Lower socioeconomic gp Parental smoking
Crowded condition, daycare
Chronic lung disease-
bronchopulmonary dysplasia
CHD + pulmonary hypertension
<3 months old Aiways anomalies
Congenital/ acquired
immunedeficiency disease
Pathophysiology Acquisition of infection
Necrosis of respiratory
epithelium (<24h)
Proliferation of goblet cells > excessive
mucus production
Nonciliated epithelium cell regeneration > impaired
secretion elimination (removed by macrophages)
Lymphocytic infiltration >
submucosal edema
Cytokine and chemokines released >
Increased cellular recruitment
Obstruction due to inflammatory cells debris +
fibrin + mucus + edema fluid (not due to
bronchoconstriction)
Bronchioles obstruction lead to hyperinflation +
increase airways resistance + atelactasis + V/Q
mismatch
Recovery with bronchiolar epithelium regeneration after 3-4
days
Clinical presentationHistory Coryza
– rhinorrhea, fever
Dry cough
Progressive
breathlessne
ss
Wheezing Feedi
ng difficu
lty
Hypothermic (<1
month)
Respiratory distress- tachypnea, nasal flare, recession, irritability
and cyanosis
Physical Sharp and dry cough
Tachypnoea and tachycardia Recession
Hyperinflated chest – sternum prominent +
liver displaced
Fine end inspiratory
crackles
High pitched wheezes- expiratory
> inspiratory
Cyanosis / pallor
Differential diagnosis
Aspiration syndrome Asthma
Pertussis (bronchitis) Pneumonia
Investitigation
FBC •Lymphocytosis
Nasopharyngeal swab/ nasal wash
•To detect RSA antigen in epithelial cell from secretion•Direct immunofluorescent antibody (IFA) staining or ELISA, PCR
Chest Xray •Hyperinflated lung due to airways obstruction, air trapping and focal atelectasis (arterial desaturation)•Increased interstitial marking and peribronchiol cuffing
Blood gas analysis •In severe cases show lowered arterial oxygen and raised CO2 tension
ECG, ECHO •May display arrhythmias or cardiomegaly
A chest radiography
revealing lung hyperinflation
with a flattened diaphragm and
bilateral atelectasis in
the right apical and left basal
regions in a 16-day-old infant
with severe bronchiolitis
Management Supportive (viral) provide adequate fluid (NG/IV) to maintain hydration and monitor for apnea (infant)
Humidified O2 delivered via nasl cannulae determined by pulse oximetry
Mist/ antibiotics/ steroids not helpful
Nebulised bronchodilator (salbutamol/ipratropium) often used but not reduce severity / illness duration
Prophylaxis- good hand hygiene and monoclonal antibody prophylaxis (im palivizumab)
Prognosis Recover with 2w
Half will have recurrent cough
+ wheeze
Bronchitis (whooping cough / pertussis) Highly infectious caused by bordetella pertussis
• Inflammation of brochi produce mixture of wheeze and coarse crackles• Main symptoms: cough(<2w if >2w caused by pertussis/ mycoplasma) and fever• Complication: pneumonia, convulsion, bronchiectasis and death (infants with apnea)
Phases
• Catarrhal phase (1w): coryza• Paroxysmal phase (3-6w): paroxysmal/spasmodic cough then inspiratory whoop, cough worse at night + vomit, can go red/blue, mucus flow from nose and mouth, apnea (infant), epistaxis (nosebleed)
and sunconjuctival haemorrhage• Convalescent phase (persist months): symptoms decrease
Investigation
• Culture of nasal swab• FBC: marked lymphocytosis
Treatment and management
• Erythromycin for eradicates organism, closed contact and prophylaxis• Immunisation reduce risk developed pertussis but not 100%