Acute Viral Laryngotracheobronchitis (Croup)
Paediatrics - Acute Viral Laryngotracheobronchitis (Croup)
General and Supportive Measures
Not all stridor is acute laryngotracheobronchitis (CROUP). Features of croup are: Age 6mo - 2 years of age, previously well child, fully immunised, with preceding upper respiratory tract infection, develops mild fever, barking cough and gradually progressive inspiratory obstruction and is otherwise well.
| Features of other diagnoses that are not CROUP | |
| < 4 months | Underlying congenital abnormality |
| Sudden onset severe obstruction | Foreign body |
| Incomplete immunization | Diphtheria |
| Dysphagia or sitting forwards | Epiglottitis, retropharyngeal abscess |
| Systemic toxicity, pyrexial | Epiglottitis, peritonsillar or retropharyngeal abscess, Staph Aureus bacterial tracheitis |
| Oral ulcers or severe oral thrush | Herpes or Candida infection |
| Aphonia and preceding hoarse voice | Laryngeal papillomatosis |
| History of previous intubation | Post-intubation injury with stenosis |
| Repeated episodes | Spasmodic croup, anatomical / functional abnormality, gastro-oesophageal reflux |
GRADING OF CROUP SEVERITY
NOTE: Grade croup only, NOT stridor from other causes. The grading implies a predictable course / prognosis, and other causes of stridor will not behave as predictably as the obstruction from croup. Grade the obstruction, not the noise, as a softer stridor may be due to either resolution OR increasing obstruction with decreased air flow!
| Severity | Inspiratory obstruction (Stridor) | Expiratory Obstruction (Stridor) | Pulsus paradoxus |
| Grade 1 | + | ||
| Grade 2 | + | + passive expiration | |
| Grade 3 | + | + active expiration using abdominal muscles | + |
| Grade 4 | cyanosis, apathy, marked retractions, impending apnoea | ||
DIAGNOSIS AND INVESTIGATIONS:
- Diagnosis is made clinically
- X-ray AP and lateral neck only helpful in excluding other diagnoses (epiglottitis, retropharyngeal abscess, foreign body). It is unnecessary in those who fit the description for viral croup and need not be done routinely. It must never delay institution of emergency treatment.
- Routinely check oxygen saturation by pulse oximetry, blood gas is not indicated and is unhelpful.
- No routine bloods, only if suspect alternative diagnosis to viral croup (Blood culture, FBC in suspected bacterial tracheitis, high fever etc)
GENERAL AND SUPPORTIVE MEASURES
- Monitor oxygen saturation, heart rate and respiratory rate.
- Monitor the nutritional status and fluid requirements.
- Avoid arterial blood gas estimations, clinical criteria are more effective in determining severity.
- Depending on severity, admit child to high care or intensive care ward.
- Keep child as happy as possible as crying aggravates airway obstruction. Encourage parents to stay with child at all times. Avoid suctioning or chest physiotherapy.
MEDICAL TREATMENT
| MEDICAL TREATMENT OF CROUP | |
| Grade 1 |
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| Grade 2 |
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| Grade 3 |
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| Grade 4 |
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Antimicrobials are not routinely indicated in viral croup. If another diagnosis is considered:
- Suspected herpes: Aciclovir IV, 10–15 mg/kg/dose 8 hourly for 5–7 days.
- Suspected pneumonia:
- Children < 20 kg: Ampicillin, IV, 12.5–25 mg/kg/dose 6 hourly
- Children > 20 kg: Ampicillin, IV, 250–500 mg, 6 hourly
- Suspected bacterial tracheitis: Cloxacillin, IV, 50 mg/kg/dose 6 hourly for 7 days.
Note:
Intubate all children with grade 3 and 4 airway obstruction not responding within one hour to adrenaline nebulisations before referral.
Refer children with an uncertain diagnosis.
Children can be discharged 6 hours after they last required an adrenaline neb to keep them Grade 1.
All children who do not have classical viral croup where another diagnoses are considered, refer to Respiratory team or ENT.