What oral corticosteroid and dose should be given to a 40 kg child with an asthma exacerbation?

Oral Corticosteroid Dosing for a 40 kg Child with Asthma Exacerbation

For a 40 kg child with an asthma exacerbation, give prednisolone or prednisone 40–60 mg orally once daily (or divided into two doses) for 3–10 days without tapering. 1, 2

Recommended Dosing Algorithm

Standard Weight-Based Calculation

• The guideline recommendation is 1–2 mg/kg/day with a maximum of 60 mg/day regardless of weight. 1, 2, 3
• For a 40 kg child, this calculates to 40–80 mg/day, but the dose is capped at 60 mg/day maximum. 1, 2, 3
• Therefore, prescribe 60 mg daily as the appropriate dose for this child. 2, 3

Severity-Based Dosing Refinement

• For mild-to-moderate exacerbations (child can speak in sentences, SpO₂ > 92% on room air, peak flow > 50% predicted): use 1 mg/kg/day = 40 mg daily. 2
• For severe exacerbations (difficulty speaking, SpO₂ < 92%, peak flow < 50% predicted, poor response to initial bronchodilators): use 2 mg/kg/day capped at 60 mg daily. 2
• Using the higher 2 mg/kg dose in mild-to-moderate cases increases behavioral side effects (anxiety, hyperactivity, aggression) without additional clinical benefit. 2, 4

Route of Administration

• Oral administration is strongly preferred and equally effective as intravenous therapy when the child can tolerate oral intake and has intact gastrointestinal absorption. 2, 5, 6
• Reserve intravenous hydrocortisone (4–7 mg/kg every 8 hours) only for children who are actively vomiting, severely ill, or unable to swallow. 2

Duration and Tapering

• Continue treatment for 3–10 days until peak expiratory flow reaches ≥70% of predicted or the child's personal best; a typical outpatient course is 5 days. 1, 2, 3
• No tapering is required for courses shorter than 7–10 days, especially when the child is already on inhaled corticosteroids. 1, 2
• Tapering short courses is unnecessary and may lead to under-dosing during the critical recovery period. 2

Concurrent Essential Therapy

• Administer systemic corticosteroids immediately upon recognition of a moderate-to-severe exacerbation; anti-inflammatory effects require 6–12 hours to become clinically apparent. 2
• Nebulized salbutamol 5 mg (or 4–8 puffs via metered-dose inhaler with spacer) every 20 minutes for three doses, then every 1–4 hours as needed. 1, 2
• Supplemental oxygen to maintain SpO₂ > 92%. 1, 2
• Add ipratropium bromide 0.25–0.5 mg to nebulized salbutamol for severe exacerbations. 1, 2

Monitoring Response

• Measure peak expiratory flow 15–30 minutes after initial treatment and reassess clinical status. 1, 2
• If no improvement within 15–30 minutes, increase nebulized β-agonist frequency to every 30 minutes and consider escalation of care. 1, 2

Critical Pitfalls to Avoid

• Never postpone systemic corticosteroids while delivering repeated bronchodilator doses alone; under-use of corticosteroids is a documented cause of preventable asthma deaths. 1, 2
• Do not use weight-based dosing that exceeds 60 mg/day; higher doses provide no additional benefit and increase adverse effects. 1, 2, 3
• Never use sedatives in a child with acute asthma; they are contraindicated and may be fatal. 2
• Do not rely solely on clinical impression; objective measurement of peak expiratory flow is required to assess severity and response. 1, 2

Discharge Planning

• Ensure the child has been stable on discharge medications for at least 24 hours with PEF > 75% of predicted and diurnal variability < 25%. 1, 2
• Provide a written asthma action plan, verify correct inhaler technique, and prescribe a peak flow meter. 1, 2
• Arrange follow-up with primary care within 1 week and a respiratory specialist within 4 weeks. 1, 2