Diagnosis of croup

The diagnosis of laryngotracheitis (laryngotracheobronchitis) is based on features of a hoarse voice or a barking cough and stridor, with or without increased work of breathing (as evidenced by chest-wall retractions). This could be directly observed, or elicited in the history. The child may have the typical brassy ‘sea-lion’ cough, and this is adequate to diagnose croup without stridor or recessions being evident.

Asthma or bronchiolitis with manifestations of lower airway obstruction occasionally co-exist with croup in the same patient, due to the common viral aetiology. If unsure, one clinical manoeuvre to distinguish wheeze from stridor is to move the stethoscope progressively closer to the larynx ? stridor will become louder. Generally, wheeze is expiratory, whereas stridor is inspiratory in timing, but this is not a reliable feature. If the clinical picture is predominantly one of asthma or bronchiolitis more than croup, lower airways disease should be treated as appropriate.

Criteria for oral steroid

These are not clear in the literature at present. Some institutions only use oral steroids when stridor is present; however, the tendency over the last 10-15 years has been towards more liberal use of steroids, since lower doses have been recognised to be equally effective. Side effects from a single dose of dexamethasone or prednisolone are likely to be extremely rare, as demonstrated by previous studies.

Criteria for Nebulised Adrenaline (Epinephrine)

Nebulised adrenaline is an effective short-term treatment for moderate and severe croup, and probably works by causing upper airway vasoconstriction, thereby decreasing mucosal oedema.

Indications are not clearly established in the literature, but most clinicians would use nebulised adrenaline for children with:

• Progressively worsening clinical condition (increasing croup severity)
• Severe croup from the outset (severe retractions)
• Hypoxaemia (SaO₂ less than 92%)
• As a temporary measure prior to intubation

Dose: depends on the type of adrenaline used

• 1:1000 L-adrenaline ampoules (1mg in 1 mL) (normal ‘crash-cart’ adrenaline vials):
  give 0.5mL/kg to max of 5mL, made up to total volume of 4mL with normal saline

or alternatively

• 1% racemic adrenaline solution:
  give 0.05mL/kg to max of 1.5mL, diluted to total 4mL with normal saline

All children who have required a single dose of nebulised adrenaline should be observed for at least three hours. Those who have improved, having received steroids, and with appropriate social supports and no other clinical concerns, may be discharged home.

Criteria for Endotracheal Intubation

This is seldom required in children who have been given steroids and is a clinical decision to be made by an experienced emergency physician, paediatrician, anaesthetist or intensivist. Consider in the child with:

• Exhaustion despite nebulised adrenaline (epinephrine)
• Severe retractions (increased work of breathing) despite nebulised adrenaline (epinephrine)

Intubation should only be performed by the most experienced operator available, preferably a paediatric anaesthetist, where available.

Criteria for Admission to Hospital

The decision to admit a child should be based on the normal practice and policy of the Emergency Department.

One possible approach would be to admit all children who:

• Have stridor at rest, audible without a stethoscope, 2 hours after oral steroid
• Have received nebulised adrenaline and not clearly improved
• Need admission for other reasons, eg remote from hospital / social reasons

Leaving the Emergency Department for admission to the ward

Determining whether a child is ‘stable’ to go to the ward is once again a clinical decision and will depend on local arrangements. Generally, transfer to the ward would be considered safe when:

• Mild retractions only, with normal oxygen saturation on room air and soft stridor only
• No indication for nebulised adrenaline (ie, condition not deteriorating)
• Ward ready and resourced to care for child

Under some circumstances it may be necessary for a doctor to accompany child to the ward.

Discharge from the Emergency Department

Doctors with the appropriate experience could allow a child to go home, typically when:

• No signs of increased work of breathing
• No stridor at rest audible
• Steroid has been administered
• Family and social factors allow

Parents should be advised to return to hospital if the child develops persisting stridor at rest. Stridor may recur when the child is upset, but should not persist once the child calms down.

Related Specialists

• Paediatrician
• Emergency Physician
• General Practitioner (GP)

Related Procedures

• Endotracheal Intubation

Related Tests

• Usually, no tests are necessary

Related Articles

• Croup: Information for Parents

By Dr Colin Parker – Emergency Physician

This article is for informational purposes only and should not be taken as medical advice. If in doubt, HealthEngine recommends consulting with a registered health practitioner.