Bronchiolitis

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Bronchiolitis\: common respiratory condition in infancy, characterised by narrowing of lower respiratory tract due to
in
Incidence\: higher in winter; episodes typically last 7-10 days.
Aetiology\: usually viral; 80% caused by RSV, others include parain
metapneumovirus.
Risk factors for severe disease\: chronic lung disease, congenital heart disease, age \<3 months, prematurity, Down's
syndrome, cystic
Symptoms\: persistent cough, wheeze, shortness of breath, prodrome of URT symptoms (fever, runny nose), apnoea in
young infants, poor feeding, dehydration signs in severe cases.
Examination
prolonged capillary re
Di
wheeze, history of atopy, salbutamol responsive), pertussis (characteristic cough, unvaccinated), GERD (chronic cough, poor
weight gain), foreign body aspiration (history of choking, monophonic wheeze), chronic heart disease (cyanosis,
hepatomegaly, murmurs).
Diagnosis\: clinical; coryzal symptoms for 3 days, followed by persistent cough, tachypnoea or chest recession, and wheeze
or crackles on auscultation.
Investigations\:
Pulse oximetry\: admit if oxygen saturation \<92%.
Chest X-ray\: not routine; used to rule out pneumonia or pneumothorax if indicated.
Management\: supportive; criteria for admission include apnoea, O2 saturation \<92%, reduced oral intake, persistent
respiratory distress, presence of risk factors, di
Supportive care\: oxygen supplementation, positive pressure (high
NG tube, IV
Complications\: dehydration, SIADH and hyponatraemia, apnoea, respiratory failure.
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Introduction

Bronchiolitis is characterised by narrowing of the lower respiratory tract due to in
up of mucus. It is a common respiratory condition in infancy. Around a third of infants develop bronchiolitis before the age
of 1, with a peak incidence around 3 to 6 months of age.
1
The incidence of bronchiolitis is linked with the winter period. Typically, children present during this time with episodes of
bronchiolitis lasting for 7-10 days.
2,3Aetiology
Bronchiolitis is usually caused by a viral infection. About 80% of cases are caused by the respiratory syncytial virus (RSV).
The other less common viral causes of bronchiolitis include\:
Parain
Rhinovirus
Adenovirus
In
Human metapneumovirus
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Risk factors

Risk factors for admission to hospital with a severe episode of bronchiolitis include\:
Chronic lung disease
Congenital heart disease
Younger than 3 months old
Prematurity
Down's syndrome
Cystic
Neuromuscular disease
2,4

Clinical features

History
Typical symptoms of bronchiolitis include\:
Persistent cough
Wheeze
Shortness of breath
A prodrome of upper respiratory tract features - fever, runny nose, cold
Symptoms typically worsen during the 2 nd rd
or 3 night of illness
Other symptoms can include\:
Apnoea – in infants younger than 6 weeks of age, also typically seen with RSV
Poor feeding – young children are obligate nasal breathers, making it di
during bronchiolitis
Symptoms of dehydration in severe disease – reduced urine output or fewer wet nappies
Other important areas to cover in the history include\:
Past medical history including birth history – ask about known risk factors for severe bronchiolitis, as listed above
Medications/allergies – this information may be useful if there are other possible di
Family history – ask if anyone in the family has been unwell, this may point towards other di
to ask about any family history of atopic conditions
Social history – ask about parental smoking, as this will exacerbate symptoms of bronchiolitis. Also ask about the child’s
situation at home (e.g. where they live, who is at home with them, the involvement of social services), as di
circumstances will reduce the threshold for admission.
Clinical examination
Typical clinical
Bilateral polyphonic expiratory wheezeTachypnoea
Tachycardia
o
Low-grade fever (\<39 )
Irritability
Other clinical
Prolonged capillary re
Cyanosis
Signs of dehydration - dry mucous membranes, sunken fontanelle in young babies
5
Reduced conscious level
6
Recessions (intercostal, subcostal or sternal) – this is a result of children having a compliant rib cage, which makes an
increased work of breathing clearly visible externally.
Figure 1.Intercostal recessions in a newborn with breathing di
7

Di

Table 1. Di
DiPneumonia
Features di
Fever >39
o
Focal crackles
Viral-induced wheeze
Persistent wheeze without crackles
Recurrent wheeze associated with a viral illness
Personal or family history of atopy
>1-year-old
Responsive to salbutamol treatment
Early-onset asthma
Persistent wheeze without crackles
Recurrent wheeze associated with triggers
Personal or family history of atopy
>1-year-old
Responsive to salbutamol treatmentB o r d e t e l l a p e r t u s s i s
or
whooping cough
Coryza
Characteristic hacking cough followed by an
inspiratory ‘whoop’
Unvaccinated
Gastro-oesophageal
re
Chronic cough
Poor weight gain
Foreign body
aspiration
Chronic heart disease
or failure
May have a history of choking
Monophonic wheeze.
8
Cyanosis
Shortness of breath
Hepatomegaly
Murmurs

Investigations

Children are diagnosed clinically with bronchiolitis if they present with coryzal symptoms lasting up to 3 days, followed by\:
1. Persistent cough and
2. Tachypnoea or chest recession and
3. Wheeze or crackles on chest auscultation.
4
Investigations do not in
Bedside investigations
Pulse oximetry\: children should be admitted if oxygen saturation is \<92%
4
Laboratory investigations
Blood tests (including arterial blood gases)\: these are not routinely performed
Imaging
Chest X-ray\: not routinely performed, but if there is an area of the lung with reduced air entry or focal crackles, this can
be used to rule out pneumonia or pneumothorax.
2

Management

Bronchiolitis is typically self-limiting. Not all children with bronchiolitis will require admission to hospital. If a child does not
require admission, it is important to provide safety netting to the parents or guardians to return if symptoms get worse.
The criteria for admission to secondary care depends on several factors including\:
Apnoea
Reduced oxygen saturation\: \<92%
Reduced oral intake\: \<50-75% of normal
Persistent respiratory distress\: signi
Presence of risk factors for severe disease, as mentioned earlier
Di
4
The management of bronchiolitis is supportive\:
Oxygen supplementation if saturations are persistently \<92%.
Positive pressure such as high
intubation and ventilation may be required.Nutritional and
bronchiolitis, a stepwise approach may be considered\:
Small and frequent oral feeds,
NG tube placement with small and frequent NG bolus feeds,
Continuous NG feeds,
IV
Support parents/guardians with smoking cessation.
Important points to note\:
Bronchodilators are not e
Antibiotics are also not e
4,5

Complications

If bronchiolitis is not diagnosed and treated, complications can include\:
Clinical dehydration
Syndrome of inappropriate antidiuretic hormone (SIADH) and subsequent hyponatraemia. Because of the risk of SIADH,
some guidelines will advocate for 2/3 maintenance NG/IV
Apnoea and respiratory failure requiring intubation and ventilation.
6

References

Patient. B r o n c h i o l i t i s . Published in 2018. Available from\: [LINK].
Goldstein H. Published in 2013. Available from\: [LINK].
Spottingthesickchild. S y m p t o m s \: D i LINK].
NICE Guidelines. B r o n c h i o l i t i s i n c h i l d r e n \: d i a g n o s i s a n d m a n a g e m e n t . Published B r o n c h i o l i t i s ( a n d R S V ) i n i n f a n t s a n d c h i l d r e n ( B e y o n d t h e B a s i c s ) . Published in in 2019. 2015. Available Available from\: from\: [LINK].
[LINK].
West Sussex Children & Young People’s Urgent Care Network. B r o n c h i o l i t i s P a t h w a y a n d A s s e s s m e n t i n A c u t e S e t t i n gs f o r
C h i l d r e n 0-2 y e a r s . Published in 2011. Available from\: [LINK].
Wikimedia Commons. I n t e r c o s t a l r e c e s s i o n s i n a n e w b o r n w i t h b r e a t h i n g d i CC BY-SA]. Available from\:
[LINK].
B r o n c h i o l i t i s i n I n f a n t s a n d C h i l d r e n \: C l i n i c a l F e a t u r e s a n d D i a gn o s i s . Published in 2020. Available from\: [LINK].

Reviewer

Dr Hannah Murch
Paediatric Emergency Medicine Consultant

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