How is the Westley croup score calculated and what treatment is recommended for each severity level?

Westley Croup Score Calculation and Treatment Algorithm

Westley Croup Score Components

The Westley croup score is calculated using five clinical parameters, with a maximum total score of 17 points:

• Level of consciousness: Normal (0), Altered (5)
• Cyanosis: None (0), With agitation (4), At rest (5)
• Stridor: None (0), With agitation (1), At rest (2)
• Air entry: Normal (0), Decreased (1), Markedly decreased (2)
• Retractions: None (0), Mild (1), Moderate (2), Severe (3)

Retraction and air entry are the most clinically significant components for predicting outcomes, while cyanosis and altered consciousness rarely occur even in severe cases 1.

Severity Classification

• Mild croup: Westley score 0-2
• Moderate croup: Westley score 3-7
• Severe croup: Westley score ≥8

Treatment Recommendations by Severity

Mild Croup (Westley Score 0-2)

Patients with Westley scores of 1-2 can be safely treated at home 1. Treatment consists of:

• Dexamethasone 0.15 mg/kg PO (single dose) - this lower dose is as effective as 0.60 mg/kg and works within 30 minutes 2, 3
• Alternative: Betamethasone 0.4 mg/kg PO 4
• Fresh/cold air exposure
• Discharge home after observation

Moderate Croup (Westley Score 3-7)

Patients with initial Westley scores ≥5 require hospitalization or extended ED observation 1. Treatment protocol:

1. Dexamethasone 0.15-0.60 mg/kg PO/IM (single dose)
2. Nebulized L-epinephrine: 0.1 mg/kg (maximum 1 mg) is as effective as the conventional 0.5 mg/kg dose (maximum 5 mg) 5
3. Observe for 2 hours after each epinephrine dose
4. Admission criteria: Consider admission after 3 total doses of racemic epinephrine 6

The evidence shows that 71.3% of patients receiving 2 doses of epinephrine were historically hospitalized, yet only 16.9% actually required additional treatment 6. Modern guidelines recommend observing up to 2 hours after the second epinephrine dose before deciding on admission, which has reduced admission rates by over 50% without increasing adverse outcomes 6.

Severe Croup (Westley Score ≥8)

Patients with Westley scores ≥6 require hospital admission 1. Treatment includes:

1. Dexamethasone 0.60 mg/kg (consider higher dose for severe cases) 3
2. Nebulized L-epinephrine (may require multiple doses)
3. Hospital admission for continuous monitoring
4. Consider ICU admission if requiring >3 epinephrine doses or showing signs of respiratory failure

Key Clinical Pearls

Timing of steroid effect: Dexamethasone 0.15 mg/kg shows benefit by 30 minutes, not the 4-6 hours previously suggested 2. This should encourage earlier treatment and less concern about delayed benefit.

Age correlation: Every year increase in age reduces the average Westley score by 21.2% 7, meaning younger children typically present with more severe disease.

Avoid unnecessary imaging: Lateral neck radiographs should be avoided unless the patient fails to respond to epinephrine, raising concern for croup-mimicking conditions like bacterial tracheitis or foreign body 6.

Rebound rate: Only 7-10% of patients experience symptom recurrence within 72 hours 7, indicating that appropriate initial treatment is highly effective.

Common Pitfalls

• Over-admitting patients after 2 doses of epinephrine: The evidence strongly supports observing these patients for 2 hours before deciding on admission 6
• Using excessive steroid doses: 0.15 mg/kg dexamethasone is likely as effective as 0.60 mg/kg for most cases 3
• Delaying steroid administration: Steroids work within 30 minutes, so early administration is critical 2
• Obtaining unnecessary radiographs: Only indicated when diagnosis is uncertain or patient fails standard therapy 6