Basics
Description
- Viral infection of the upper respiratory tract
- Most commonly presents in children 6 mo-3 yr:
- Laryngotracheitis/laryngotracheobronchitis
- Inspiratory stridor owing to extrathoracic airway obstruction
- Expiratory wheeze suggests lower airway involvement.
- Inflammatory edema of subglottic region
- Narrowest part of pediatric airway
- May progress to respiratory failure
Etiology
- Parainfluenza types 1, 2, and 3
- Human coronavirus NL63
- Influenza A and B
- Adenoviruses
- Respiratory syncytial virus
- Measles
- Mycoplasma pneumoniae
- Herpes simplex
Diagnosis
Signs and Symptoms
History
- Nonspecific upper respiratory prodrome with or without fever
- Duration of illness
- History of tracheal intubation
- Possibility of foreign body aspiration
- Previous episodes
- History of wheeze
- Immunization status (Haemophilus influenzae type b [HIB]; diphtheria, pertussis, and tetanus [DPT]), influenza
Physical Exam
- Rarely toxic appearing
- Cyanosis (not present in majority of patients. If present, suggests severe disease)
- Prefer upright position
- Quality of cry/voice
- Drooling/trismus/limited neck extension
- Mental status
- Stridor at rest, increased work of breathing
- Hydration status
- Westley croup score (max. total points: 17):
- Stridor (inspiratory or biphasic):
- 0 = None
- 1 = Audible with stethoscope at rest
- 2 = Audible without stethoscope at rest
- Retractions:
- 0 = None
- 1 = Mild
- 2 = Moderate
- 3 = Severe
- Air entry:
- 0 = Normal
- 1 = Decreased
- 2 = Severely decreased
- Cyanosis:
- 0 = None
- 4 = With agitation
- 5 = At rest
- Level of consciousness:
Diagnosis Tests & Interpretation
Lab
- Continuous pulse oximetry
- Other tests are not routinely indicated.
Imaging
Anteroposterior (AP) and lateral neck radiographs: �
- Steeple sign indicates narrowing of subglottic trachea.
- Imaging not routinely indicated, unless atypical presentation or clinical course
- Subject to misinterpretation and should not be used as sole means to exclude epiglottitis
- Should not delay definitive visualization and intubation in OR in child with concern for epiglottitis or bacterial tracheitis
- Monitor child during imaging, if done.
Differential Diagnosis
- Infection:
- Bacterial tracheitis
- Retropharyngeal or parapharyngeal abscess
- Epiglottitis
- Peritonsillar abscess
- Diphtheria
- Foreign body (airway or esophageal)
- Angioedema
- Congenital airway anomaly:
- Laryngomalacia, tracheomalacia, laryngeal cleft
- Acquired subglottic stenosis
- Vocal cord paralysis
- Thermal or chemical injury to upper airway
- Hemangioma
- Laryngeal papillomatosis
- Vocal cord dysfunction (VCD) (adolescents)
Treatment
Pre-Hospital
- Allow child to maintain position of comfort.
- Defer interventions that may distress child such as:
- If severe distress:
- Immediate nebulized epinephrine
Initial Stabilization/Therapy
- Nebulized racemic epinephrine or l-epinephrine if distress or stridor at rest:
- l-epinephrine containing only the active isomer; has been shown to be therapeutically equivalent to racemic epinephrine
- Oxygen (via blow-by) for suspected or documented hypoxia suggesting severe disease
- Mist therapy often used, but no evidence for efficacy
- Dexamethasone:
- Reduces need for intubation, shortens length of stay, and reduces admissions and return visits and may have effects within 30 min
- Effective even in mild croup (Westley croup score ≤2)
- If poor response to nebulized racemic epinephrine or l-epinephrine:
- Consider trial of heliox:
- Heliox, when available, has been used to decrease the work of breathing in patients with an incomplete response to epinephrine.
- If impending or existing respiratory failure despite aforementioned therapy:
- Tracheal intubation by most experienced person available
- Use uncuffed endotracheal tube (ETT) 0.5-1 mm smaller than usual size.
- If epiglottitis or foreign body suspected:
- Ideally, to OR for inhalational anesthesia, direct laryngoscopy, and intubation
- Surgeon standing by for emergent tracheostomy
Ed Treatment/Procedures
See "Initial Stabilization."� �
Medication
- Racemic epinephrine 2.25%: 0.25-0.5 mL nebulized in 2.5 mL NS
- l-epinephrine 1:1,000: 5 mL (5 mg) nebulized
- Dexamethasone: Single dose of 0.6 mg/kg (max. 10 mg) PO (use crushed tablet) or IV preparation (4 mg/mL) PO with flavored syrup. Equally effective when given PO, IV, or IM. Lower doses may be effective.
- Heliox (70% helium: 30% oxygen mixture administered via face mask or tent house)
- Antibiotics: Not indicated
Follow-Up
Disposition
Admission Criteria
- Young infants, pre-existing upper airway obstruction
- Persistent or recurrent stridor at rest unresponsive to nebulized epinephrine, or recurring during 2-3 hr observation
- Pediatric intensive care unit:
- Persistent severe obstruction
- Need for frequent epinephrine treatments and/or heliox
- Tracheal intubation with assisted ventilation
Discharge Criteria
- Normal oxygenation in room air
- No stridor at rest after brief observation
- Children initially given epinephrine who no longer have stridor at rest should be observed for a min. of 2-3 hr
- Reliable caretaker, communication, and transport
Issues for Referral
- Concern for underlying anatomic abnormality (young age, history of intubation, frequent recurrence)
- Infants <1 year with stridor unassociated with laryngotracheobronchitis may require endoscopic evaluation
Follow-Up Recommendations
- Most children with croup do not require specific follow-up.
- Patients who have had prolonged stridor, or acute worsening of stridor should seek care with their primary care physician or return to the ED.
Pearls and Pitfalls
- Beware young infants with stridor
- High incidence of congenital abnormalities
- Mild and early epiglottitis or bacterial tracheitis may mimic croup
Additional Reading
- Bjornson �C, Russell �KF, Vandermeer �B, et al. Nebulized epinephrine for croup in children. Cochrane Database Syst Rev. 2011;16(2):CD006619.
- Cherry �JD. Clinical practice. Croup. NEJM. 2008;358:384-391.
- Cooper �T, Kuruvilla �G, Persad �R, et al. Atypical croup: Association with airway lesions, atopy, and esophagitis. Otolaryngol Head Neck Surg. 2012;147(2):209-214.
- Dobrovoljac �M, Geelhoed �GC. How fast does oral dexamethasone work in mild to moderately severe croup? A randomized double-blinded clinical trial. Emerg Med Australas. 2012;24(1):79-85.
- Russell �KF, Liang �Y, O'Gorman �K, et. al. Glucocorticoids for croup. Cochrane Database Syst Rev. 2011;19(1):CD001955.
- Scolnik �D, Coates �AL, Stephens �D. Controlled delivery of high vs. low humidity vs. mist therapy for croup in emergency departments. JAMA. 2006;295:1274-1280.
- Sung �JY, Lee �HJ, Eun �BW, et. al. Role of human coronavirus NL63 in hospitalized children with croup. Pediatr Infect Dis J. 2010;29(9):822-826.
- Zoumalan �R, Maddalozzo �J, Holinger �LD. Etiology of Stridor in infants. Ann Otolaryng, Rhinology, Laryngology. 2007;116(5):329-334.
See Also (Topic, Algorithm, Electronic Media Element)
Epiglottitis �
Codes
ICD9
- 464.4 Croup
- 464.20 Acute laryngotracheitis without mention of obstruction
ICD10
- J04.2 Acute laryngotracheitis
- J05.0 Acute obstructive laryngitis [croup]
SNOMED
- 71186008 Croup (disorder)
- 275495004 Acute fibrinous laryngotracheobronchitis (disorder)
- 232430006 Recurrent allergic croup (disorder)