Steroid Injection for Asthma Flare-Up
For patients with acute asthma exacerbations, intravenous hydrocortisone 200 mg should be administered immediately, followed by 200 mg every 6 hours if the patient is vomiting, severely ill, or unable to tolerate oral medications. 1, 2
Route Selection Algorithm
Oral corticosteroids are the preferred first-line treatment and are equally effective as intravenous therapy when gastrointestinal absorption is intact. 2, 3, 4 Injectable steroids should be reserved for specific clinical scenarios:
When to Use Injectable Steroids:
- Patient is actively vomiting 1, 2
- Severe illness preventing oral intake 1, 2
- Life-threatening features present (SpO2 <92%, silent chest, exhaustion, altered consciousness) 1
- Inability to swallow or maintain oral medications 2
When Oral Steroids Are Appropriate:
- Patient can tolerate oral intake 2
- Gastrointestinal function is intact 2
- Moderate exacerbations without life-threatening features 1
Injectable Steroid Options and Dosing
Intravenous Hydrocortisone (Preferred Injectable Route):
- Initial dose: 200 mg IV immediately 1, 2
- Maintenance: 200 mg IV every 6 hours 1, 2
- Continue until patient can tolerate oral medications 2
- Transition to oral prednisone 40-60 mg daily within 24-48 hours once oral intake is tolerated 2
Intramuscular Options (Alternative):
- Methylprednisolone acetate 40-250 mg IM can be used 1, 5
- IM route shows similar efficacy to oral steroids for preventing relapse 6
- IM dexamethasone is an alternative, though specific dosing for acute asthma is less well-established in guidelines 6
Important caveat: There is no advantage to IV or IM administration over oral therapy when GI absorption is intact, and oral administration is strongly preferred due to lower cost, less invasiveness, and equivalent efficacy. 2, 3, 4
Concurrent Essential Therapy
Injectable steroids must be combined with:
- High-dose nebulized beta-agonists (salbutamol 5 mg or terbutaline 10 mg) via oxygen-driven nebulizer 1, 2
- High-flow oxygen 40-60% to maintain SpO2 >92% 2
- Ipratropium bromide 0.5 mg added to beta-agonist if life-threatening features present 1
Monitoring Response
- Measure peak expiratory flow 15-30 minutes after starting treatment 1, 2
- Continue monitoring every 15-30 minutes initially if not improving 1, 2
- Maintain continuous pulse oximetry with SpO2 target >92% 2
- Repeat blood gases within 2 hours if initial PaO2 <8 kPa (60 mmHg) or if patient deteriorates 2
Transition to Oral Therapy
Switch from IV to oral steroids within 24-48 hours once the patient tolerates oral intake: 2
- Oral prednisone 40-60 mg daily until peak expiratory flow reaches 70% of predicted 2
- Total course typically 5-10 days 2
- No tapering necessary for courses <7-10 days, especially if on inhaled corticosteroids 2
Critical Pitfalls to Avoid
- Do not delay steroid administration - anti-inflammatory effects take 6-12 hours to become apparent, making early administration crucial 2
- Do not use unnecessarily high doses - doses >80 mg/day methylprednisolone equivalent show no additional benefit 7
- Do not use IM/IV route when oral is feasible - oral administration is equally effective and substantially less expensive (approximately 10 times cost difference) 4
- Do not give injectable steroids alone without concurrent bronchodilators - beta-agonists remain the cornerstone of acute treatment 1, 2
Evidence Quality Note
The recommendation for hydrocortisone 200 mg IV every 6 hours comes from the British Thoracic Society guidelines 1 and is reinforced by more recent guideline summaries 2. Research evidence demonstrates no superiority of IV over oral routes when GI function is intact 3, 4, supporting the preference for oral therapy whenever possible.