Overview
Definition:
Croup, also known as acute laryngotracheobronchitis, is a common childhood respiratory illness characterized by inflammation of the upper airway, primarily the larynx and trachea
This inflammation leads to characteristic symptoms such as a barky cough, stridor, and hoarseness
Inpatient care is typically reserved for moderate to severe cases requiring airway support or close monitoring.
Epidemiology:
Croup is most common in children aged 6 months to 3 years, with a peak incidence between 6 and 18 months
It is predominantly a viral illness, with parainfluenza viruses being the most frequent causative agents, followed by respiratory syncytial virus (RSV), adenovirus, and influenza
Seasonal variations are observed, with a higher incidence in fall and winter.
Clinical Significance:
While most cases of croup are mild and self-limiting, severe presentations can lead to significant respiratory distress and airway obstruction, necessitating prompt medical intervention
Understanding inpatient management strategies, particularly the appropriate use and weaning of racemic epinephrine, is crucial for pediatric residents preparing for DNB and NEET SS examinations
Effective management prevents progression to respiratory failure and reduces hospital stay.
Clinical Presentation
Symptoms:
Typically begins with upper respiratory tract infection symptoms: rhinorrhea, mild fever, and cough
Progresses to a distinctive barky (seal-like) cough, hoarseness, and inspiratory stridor
Symptoms are often worse at night and may improve spontaneously during the day
Severe cases present with increased work of breathing, retractions, tachypnea, and cyanosis.
Signs:
Inspiratory stridor is the hallmark sign
Barky cough
Hoarseness
Mild to moderate respiratory distress with tachypnea and subcostal, intercostal, or suprasternal retractions
Nasal flaring
Accessory muscle use
In severe cases, observe pallor, lethargy, and potential cyanosis.
Diagnostic Criteria:
Diagnosis is primarily clinical, based on the characteristic history and physical examination findings
There are no specific laboratory or imaging criteria for diagnosis
Westley croup severity score is a validated tool to objectively assess severity and guide management decisions.
Diagnostic Approach
History Taking:
Key questions include: onset and duration of cough and stridor, presence of fever, preceding URI symptoms, exposure to sick contacts, history of prematurity or underlying respiratory conditions, and any previous episodes
Red flags include rapid onset of severe distress, drooling, inability to swallow, tripod positioning, and absence of a barky cough (suggesting epiglottitis).
Physical Examination:
Assess general appearance, level of consciousness, and hydration status
Focus on respiratory effort: respiratory rate, presence and severity of retractions, accessory muscle use, nasal flaring, and stridor (inspiratory, expiratory, or both)
Auscultate lungs for air entry and presence of wheezes or crackles
Evaluate for signs of distress like pallor or cyanosis.
Investigations:
Generally, no investigations are required for mild to moderate croup
For severe cases or when differential diagnoses are considered, lateral neck X-ray may show the characteristic "steeple sign" (narrowing of the tracheal lumen)
However, this is often unnecessary and can delay treatment
Arterial blood gas (ABG) may be indicated in severe distress to assess oxygenation and ventilation
Complete blood count (CBC) and viral studies are rarely helpful in routine management.
Differential Diagnosis:
Bacterial tracheitis (more toxic appearing, higher fever, purulent secretions, unremitting cough)
foreign body aspiration (sudden onset, often witnessed event, localized findings)
anaphylaxis (rapid onset, urticaria, bronchospasm)
laryngeal foreign body
retropharyngeal or prevertebral abscess (neck stiffness, severe sore throat, difficulty swallowing).
Management
Initial Management:
Assess airway patency and severity using the Westley score
Provide supplemental oxygen if hypoxic (SpO2 <92%)
Calm the child to reduce anxiety and airway resistance
Cool mist or humidified air may provide symptomatic relief
For moderate to severe croup, administer racemic epinephrine.
Medical Management:
Racemic epinephrine: Administered via nebulizer
Dilution: 0.05 mg/kg (maximum 5 mg) of racemic epinephrine in 3 mL of normal saline
Onset of action is rapid, providing temporary relief for 2-4 hours
Steroids: Dexamethasone 0.6 mg/kg (maximum 10 mg) IM or PO is recommended for moderate to severe croup, to reduce airway inflammation
It does not provide immediate relief but reduces the need for hospitalization and re-treatment
Antibiotics are not indicated as croup is typically viral.
Surgical Management:
Rarely indicated for croup
Tracheostomy may be considered in extremely severe, refractory cases with impending respiratory arrest that do not respond to medical management
This is an uncommon scenario.
Supportive Care:
Continuous cardiorespiratory monitoring: including pulse oximetry, heart rate, and respiratory rate
Maintain adequate hydration: offer oral fluids frequently if tolerated, or intravenous fluids if significant dehydration or work of breathing prevents oral intake
Monitor for signs of worsening respiratory distress and response to treatment
Isolation may be considered in cases of known influenza or RSV infection.
Racemic Epinephrine Weaning
Indications For Administration:
Moderate to severe croup (Westley score > 2)
significant stridor at rest
increased work of breathing
hypoxia.
Monitoring Response:
Observe for reduction in stridor, decreased work of breathing, improved oxygen saturation, and increased activity level
Improvement is typically temporary (2-4 hours), requiring re-evaluation
Observe for rebound phenomenon or paradoxical worsening of symptoms after the initial response.
Weaning Criteria:
Signs of sustained improvement: minimal or no stridor at rest
normal respiratory rate for age
normal oxygen saturation (>94% on room air)
child is calm and playful
able to tolerate oral intake
Dexamethasone should have been administered for at least 4 hours to allow its anti-inflammatory effects to develop.
Weaning Protocol:
After initial improvement with racemic epinephrine, monitor closely
If the child remains clinically stable for a period (e.g., 2-4 hours) without significant stridor or distress on room air, a trial without further epinephrine can be initiated
If symptoms return or worsen, repeat doses of racemic epinephrine may be necessary, but prolonged or frequent use is generally discouraged due to rebound effects and potential for myocardial irritation
Discontinuation is based on sustained clinical improvement and absence of significant stridor at rest.
When To Resume Treatment:
If stridor returns to baseline or worsens, or if signs of respiratory distress reappear after discontinuation, repeat doses of racemic epinephrine may be indicated, up to a certain limit (e.g., 2-3 doses over several hours) with careful monitoring
Continuous observation is paramount.
Complications
Early Complications:
Respiratory failure requiring intubation
bacterial superinfection (e.g., bacterial tracheitis, pneumonia)
otitis media
pneumonia.
Late Complications:
Rarely, prolonged intubation can lead to subglottic stenosis
Recurrent croup can occur in some children.
Prevention Strategies:
Prompt recognition and management of moderate to severe croup
appropriate use of steroids and racemic epinephrine
close monitoring for signs of deterioration
aggressive management of any signs of secondary bacterial infection.
Prognosis
Factors Affecting Prognosis:
Severity of initial presentation
presence of comorbidities (e.g., prematurity, congenital airway anomalies)
timeliness and appropriateness of medical intervention
Most children with mild croup recover completely within a week.
Outcomes:
With timely and appropriate inpatient management, most children with moderate to severe croup have a good prognosis and are discharged within 24-72 hours
Intubation is required in a small percentage of cases.
Follow Up:
Follow-up is generally not required for uncomplicated cases of mild croup
For children who required hospitalization or significant intervention, follow-up with their pediatrician may be recommended to ensure complete recovery and address any persistent symptoms or concerns about recurrent episodes.
Key Points
Exam Focus:
Differentiating croup from bacterial tracheitis and epiglottitis
Understanding the indications, dosage, and monitoring for racemic epinephrine
Recognizing the role and timing of dexamethasone
Knowing the criteria for racemic epinephrine weaning.
Clinical Pearls:
Always assess the child's temperament and ability to tolerate oral intake before making decisions about hydration and oral medications
A child who is calm and playful is less likely to have severe airway compromise
The "steeple sign" on X-ray is suggestive but not diagnostic, and performing X-rays should not delay necessary treatment
Rebound phenomenon after racemic epinephrine is common and requires careful observation.
Common Mistakes:
Over-reliance on X-ray findings, delaying treatment
Underestimating the severity of respiratory distress
Inappropriately using antibiotics
Inadequate monitoring of children receiving racemic epinephrine
Premature discontinuation of racemic epinephrine without sustained clinical improvement.