Croup Flashcards
Croup introduction?
Laryngotracheobronchitis, commonly known as croup, is an upper respiratory tract infection commonly caused by a viral infection.
Croup occurs in younger children aged 6 months to 3 years old and presents with a characteristic barking cough, inspiratory stridor, and respiratory distress.
Causes of Croup?
The common causes for croup are:
- Parainfluenza 1 and 2
- Influenza
- Adenovirus
- Respiratory Syncytial Virus (RSV)
Croup used to be caused by diphtheria. Croup caused by diphtheria leads to epiglottitis and has a high mortality.
Laryngo-tracheo-bronchitis. Herpes, measles or other virus. Diphtheria. Foreign body. Haemophilus Influenza epiglottitis. Laryngomalacia and URT infection. Retropharyngeal abscess (dysphagia).
Risk factors
Risk factors for croup include:
- Age: croup most commonly occurs in children aged 6-36 months.
- Family history
- Male (the male: female ratio is approximately 1.4:1)
- Congenital airway narrowing
- Hyperactive airways
- Acquired airway narrowing
Clinical features (Symptoms)?
Typical symptoms of croup include:
- Hoarse voice
- Barking cough (often described as ‘seal-like & is worse at night)
- Inspiratory stridor
- Fever
Clinical findings (Signs)?
Typical clinical findings in croup include: STRIDOR 1. Increased work of breathing: intercostal and sternal recession 2. Agitation: in severe croup 3. Lethargy: in severe croup 4. Cyanosis: in severe croup 5. Tachypnea 6. Tachycardia 7. Pulsus paradoxus
Assessment of severity of Croup
- Mild croup: no stridor at rest (may develop stridor with crying), barking cough, hoarse cry and no or mild work of breathing (recessions).
- Moderate croup: moderate stridor at rest with mild work of breathing with little or no agitation.
- Severe croup: significant stridor at rest (though this may become more silent as the obstruction worsens) with severe respiratory distress including sternal recession. The child may appear anxious, pale and tired.
- Impending respiratory failure: reduced consciousness, fatigue, listlessness, marked retractions, absent respiratory sounds, tachycardia and cyanosis/pallor.
DDx
Important differential diagnoses to consider include:
- Epiglottitis: commonly caused by Haemophilus influenzae and presents without the barking cough seen in croup. The child will appear anxious, pale and ‘toxic’. The difficulty swallowing is associated with increased drooling, fever, and typically patients sit in an upright position. Children with suspected epiglottitis should have minimal handling, do not examine the mouth or upset the child as this may precipitate airway complete obstruction.
- Upper airway abscess (such as peritonsillar, parapharyngeal and retropharyngeal): presents with fevers, stiff neck, torticollis, drooling and ‘hot potato voice’. There is an absence of the barking cough.
- Foreign body inhalation: sudden onset stridor and respiratory distress often with a history of choking. May also present with a barking cough and stridor depending on the location of the obstruction. Importantly, there will be no fever.
Diagnostic investigation
- Clinical findings
- Lateral x-ray: A chest X-ray in croup will demonstrate the “Steeple sign” due to subglottic narrowing.
REMEMBER: A lateral airway X-ray in children may be considered to rule out foreign body inhalation. CXR may identify Radio-opaque
General Management of Croup
General and supportive:
- Monitor oxygen saturation, heart rate, and respiratory rate
- Monitor nutritional status and fluid requirements
- Keep child calm- crying aggravates airway obstruction
- Depending on the severity, admit the child to high care or intensive ward.
Management of Grade 1: inspiratory stridor only
- Prednisone, oral, 2mg/kg, immediately as a single dose or Dexamethasone, IV/IM 0.5mg/kg as a single dose. Avoid steroids in patients with measles or herpes infection
Management of Grade 2: inspiratory and expiratory stridor
- Steroids Prednisone, oral, 2mg/kg, immediately as a single dose or Dexamethasone, IV/IM, 0.5mg/kg as a single dose. Avoid steroids in patients with measles or herpes infection.
- (Adrenaline) Epinephrine, 1:1000, diluted in sodium chloride 0.9% nebulized, immediately
- Dilute 1ml of 1:1000 epinephrine with 1ml sodium chloride 0.9% and nebulise with 100% warm humidified oxygen.
- Repeat every 15-30 min until expiratory stridor disappears
Management of Grade 3: inspiratory and expiratory stridor with active expiration, using abdominal muscles
> > Treat as (grade 2), but nebulized Adrenaline continuously
Require intensive care as they have critical airway obstruction. If no improvement within an hour, refer urgently. Intubate (preferably under general anesthesia) before referral if possible
Management of Grade 4: Cyanosis, apathy, marked retractions, impending apnoea
> Continue steroids as above
>Continue Adrenaline (Epinephrine) nebulisation with 100% warm humidified oxygen.
>Emergency Intubation or intubation under general anesthesia (if available)
>If unable to intubate, bag and mask ventilate and Refer urgently
Complications of Croup
- Atelectasis: a collapsed or airless state of the lung, which may be acute or chronic and may involve all or part of the lung
- Pneumothorax
- Secondary bacterial infection
- Otitis media
Diagnostic criteria
- A previously healthy child who, a day or two after the onset of an URTI, develops progressive airway obstruction with Stridor and Barking cough.
- Mild fever may be present
- Stridor becomes softer as airway obstruction becomes more severe.