Bronchiolitis is an inflammation of the small airways (bronchioles) commonly caused by viral infection, especially respiratory syncytial virus (RSV) in infants under 1 year old. It causes wheezing and difficulty breathing. Clinical features include cough, wheezing, respiratory distress, and feeding difficulties. Chest x-ray may show hyperinflation of the lungs. Diagnosis is usually made clinically based on symptoms and age of the child. Treatment focuses on supportive care and monitoring for signs of worsening respiratory distress.
2. Definition
• Bronchiolitis is a first time wheezing
with a viral respiratory infection.
• It is a common respiratory illness in
children less than 24 months with its
peak incidence between 3 to 6 months
of age.
3. The common causal organisms of
bronchiolitis
• Respiratory syncytial virus (RSV) is
responsible for >50% of cases .
• Other agents include parainfluenza
adenovirus, Mycoplasma, and,
occasionally, other viruses.
• Human metapneumovirus is an
important primary cause of viral
respiratory infection or it can occur
as a co-infection with RSV
4. Epidemiology
• A common respiratory illness especially in
infants aged 1 to 6 months old
• Cyclical periodicity with annual peaks occurs
in November,December and January
.
5. Pathophysiology
1)RSV infection incites a complex immune response.
Eosinophils degranulate and release eosinophil cationic
protein, which is cytotoxic to airway epithelium.
2)Immunoglobulin E (IgE) antibody release may also be
related to wheezing.
3)Other mediators invoked in the pathogenesis of airway
inflammation include
chemokines such as interleukin 8 (IL-8), macrophage
inflammatory protein (MIP) 1α.
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9. • RSV-infected infants who wheeze express higher
levels of interferon-γ in the airway as well as
leukotrienes. RSV co-infection with
metapneumovirus can be more severe than
monoinfection
10. Acute bronchiolitis is characterized by bronchiolar
obstruction with edema, mucus, and cellular debris.
Resistance in the small air passages is increased
during both inspiration and exhalation, but because
the radius of an airway is smaller during expiration,
the resultant respiratory obstruction leads to early air
trapping and overinflation.
If obstruction becomes complete, there will be
resorption of trapped distal air, and the child will
develop atelectasis
11. Clinical features
• Coryzal symptoms precede a sharp,dry
cough,increasing breathlessness
• Wheezing is often:High
pitched,expiratory>inspiratory
• Feeding difficulty associated with increasing
dyspnoea
• Recurrent apnoea
12. •Subcostal and intercostal recession
•Hyperinflation of the chest:sternum
prominent,liver displaced downwards
•Fine end-inspiratory crackles
•Tachycardia
•Cyanosis or pallor
13. Investigations
A chest ray is not routinely required,but
recommended for children with:
1)severe respiratory distress
2)unusual clinical features
3)an underlying cardiac or chronic respiratory
disorder
4)Admission to intensive care
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15. chest X-ray shows
hyperinflation of the
lungs with flattening of
the diaphragm,
horizontal ribs and
increased hilar bronchial
markings. Note: chest X-
ray is rarely helpful in
bronchiolitis.
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16. The diagnosis is clinical,
particularly in a previously
healthy infant presenting with a
first-time wheezing episode
during a community outbreak.
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17. A majority of chidren with viral bronchiolitis has mild illness and
about 1% of these children require hospital admission
Guideline for hospital admission :
Home Management Hospital Management
Age<than 3 months No Yes
Toxic looking No Yes
Chest recession Mild Moderate/severe
Central cynosis No Yes
Wheeze Yes Yes
Crepitations on auscultation Yes Yes
Feeding Well Difficult
Apnoe No Yes
Oxygen saturation >95% <93%
High risk group No Yes
18. Management outline
1)General measures:
•careful assessment of the respiratory status and
oxygenation is critical
•Arterial oxygenation by pulse oximetry Sp02 should be
performed at presentation and maintain above 93%
-administer supplemental humidified oxygen if necessary
•Monitor for signs of impending respiratory failure
-inability to maintain satisfactory Spo2 on inspired
oxygen>40% or a rising pCO2
•Very young infants are at risk of apnoea require greater
vigilance
19. 2)Nutrition and Fluid therapy
Feeding.Infants admitted with viral brochiolitis frequently have poor
feeding are at risk of aspiration and may be dehydrated.Small frequent
feeds as tolerated can be allowed in children with moderate respiratory
distress.Naso gastric feeding maybe useful in these children who refuse
to feed and also to empty the dilated stomach.
Intravenous fluids for children with severe respiratory
distress,cyanosis,apnoea.Fluid therapy should be restricted to
maintenance requirement of 100ml/kg/day for infants.
3)Pharmacotherapy:
•Inhaled β-2 agonists:A trial of nebulised β-2 agonists,given in
oxygen,may be considered in infants with viral
bronchiolitis.Vigilant and regular assessment of the child should
be carried out if such a traetment is provided
•Inhaled steroidsRandomised controlled trials of the use of inhaled
steroids for treatment of viral brochiolitis demonstrated
nomeaningful benefit.
20. 4.Antibiotic
Recommended for all infants with:
• recurrent apnoea and circulatory impairment,
• - possibility of septicaemia
• - acute clinical deterioration�
• - high white cell count
• - progressive infiltrative changes on chest
radiograph
21. Prevention
Passive immunization with humanised RSV
specific monoclonal antibodies (Palivizumab)
prophylaxis is given during the expected
annual RSV outbreak season and is effective
in reducing the incidence of hospitalization
and severe respiratory disease in infants in
the hisk risk categories.
22. Recommended catagories of infants for
passive immunization
1.Chronic lung disease
Children or infants<24 months of age who
requiredmedical treatment in the last 6 months before
the anticipated RSV season.Medical treatment includes
supplementary oxygen,corticosteroids,brochodilators
and diuretic.
2.Premature infants less thyan 32 weeks getation
without chronic lung disease
•Infants less than 28 weeks gestation up to 12 months
of age at the start of the RSV season
•Infants between 28-32 weeks gestation up to 6 months
of age at the start of the RSV season
24. CASE : A CHESTY INFANT
Max is a 3-month-old boy seen in the community by his GP. He
developed a runny nose and bit of a cough 2 days ago but has
become progressively more chesty and has now gone off his
feeds and is having far fewer wet nappies. He has two older
siblings who also have colds. He was born at 34 weeks’
gestation but had no significant neonatal problems and went
home at 2 weeks of age. Both parents smoke but not in the
house.His mother had asthma as a child.
Examination:
Max is miserable but alert. His airway is clear. He is febrile
(37.8C) and has copious clear nasal secretions and a dry
wheezy cough. His respiratory rate is 56 breaths/min with
tracheal tug and intercostal and subcostal recession. On
auscultation, there are widespread fine crackles and expiratory
wheeze. The remainder of the examination is unremarkable.
• What is the most likely diagnosis?
• What is the commonest causative organism?
• What are the indications for referral to hospital?
• What is the management in hospital?