IM Adrenaline in Near-Fatal Asthma: BTS Guidelines
The 1993 BTS guidelines do NOT recommend intramuscular adrenaline as part of standard management for near-fatal asthma, but reserve subcutaneous adrenaline specifically for catastrophic sudden severe (brittle) asthma in select high-risk patients with a pre-arranged management plan. 1
Standard Management for Life-Threatening Asthma
The BTS guidelines clearly outline immediate management for life-threatening asthma without including IM adrenaline:
First-line therapy includes:
- High-flow oxygen (40-60%) 1, 2
- Nebulised beta-agonists (salbutamol 5 mg or terbutaline 10 mg) via oxygen 1
- Systemic corticosteroids (prednisolone 30-60 mg orally OR hydrocortisone 200 mg IV) 1, 2
For life-threatening features (PEF <33%, silent chest, cyanosis, bradycardia, confusion, exhaustion):
- Add nebulised ipratropium 0.5 mg 1
- Give IV aminophylline (250 mg over 20 minutes) OR IV salbutamol/terbutaline (250 µg over 10 minutes) 1
The Exception: Catastrophic Sudden Severe (Brittle) Asthma
IM/subcutaneous adrenaline is ONLY mentioned for a specific subset of patients:
The BTS guidelines describe an "unusual but important group" at risk of sudden death whose asthma becomes severe within minutes to hours. 1
For these pre-identified high-risk patients with a mutually agreed management plan:
- A syringe preloaded with adrenaline (0.5 mg) for subcutaneous injection may be kept at home 1
- This is considered only if previous standard management has failed 1
- The patient or relative must be trained in its use under supervision 1
- These patients should wear Medic-Alert bracelets and be under constant respiratory physician review 1
Important Clinical Context
The absence of IM adrenaline from standard BTS protocols is notable because:
- The guidelines explicitly list "unhelpful treatments" but do not include adrenaline in this category 1
- However, adrenaline is conspicuously absent from the stepwise management algorithm for acute severe and life-threatening asthma 1
- More recent evidence suggests IV adrenaline may be considered in acute fulminant asthma (1-10 µg/min infusion) in ICU settings, though this represents evolution beyond the 1993 BTS guidelines 3
Research evidence shows:
- Nebulised adrenaline has similar bronchodilator efficacy to salbutamol in acute severe asthma 4
- IV adrenaline appears safe in younger adults with life-threatening asthma 5
- However, current international guidelines recommend against routine epinephrine use except with concomitant anaphylaxis or angioedema 6
Critical Pitfalls to Avoid
- Do not delay first-line therapy (oxygen, nebulised beta-agonists, systemic steroids) while considering adrenaline 1, 2
- Do not use IM adrenaline routinely in standard acute severe asthma—it is not part of the BTS algorithm 1
- Do not confuse asthma management with anaphylaxis management, where IM adrenaline IS first-line therapy 7
- Recognize that IV adrenaline requires ICU-level monitoring and should only be used by experienced clinicians in life-threatening cases unresponsive to standard therapy 3, 5