Bronchiolitis is an inflammatory disease of the small airways caused primarily by Respiratory Syncytial Virus (RSV) in infants under 1 year old. It leads to obstruction of the small airways due to inflammation, mucus production, and edema. Clinically, infants present with rhinorrhea, cough, tachypnea, wheezing and respiratory distress. Chest X-ray may show hyperinflated lungs. Management is supportive with oxygen, hydration and sometimes bronchodilators. Most infants recover within 2 weeks but some may develop long-term wheezing.
3. 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
4.
5. 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
11. Investitigation
• Lymphocytosis
FBC
• To detect RSA antigen in epithelial cell from secretion
• Direct immunofluorescent antibody (IFA) staining or
ELISA, PCR
Nasopharyngeal
swab/ nasal wash
• Hyperinflated lung due to airways obstruction, air
trapping and focal atelectasis (arterial desaturation)
• Increased interstitial marking and peribronchiol cuffing
Chest Xray
• In severe cases show lowered arterial oxygen and raised
CO2 tensionBlood gas analysis
• May display arrhythmias or cardiomegaly
ECG, ECHO
13. 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
Following adenovirus
infection > permanent
airways damage
(bronchiolitis
obliterans)
14. Bronchitis (whooping cough / 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)
Highly infectious caused by bordetella pertussis
•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
Phases
•Culture of nasal swab
•FBC: marked lymphocytosis
Investigation
•Erythromycin for eradicates organism, closed contact and prophylaxis
•Immunisation reduce risk developed pertussis but not 100%
Treatment and management