Why is the paediatric adrenaline dose the same for anaphylaxis and cardiac arrest?

Why Pediatric Adrenaline Doses Differ Between Anaphylaxis and Cardiac Arrest

The pediatric adrenaline dose is NOT the same for anaphylaxis and cardiac arrest—this is a dangerous misconception that has led to iatrogenic overdoses and life-threatening cardiac complications. 1

Correct Dosing by Indication

Anaphylaxis (Intramuscular Route)

• Dose: 0.01 mg/kg of 1:1000 concentration (maximum 0.3-0.5 mg) 2, 3
• Route: Intramuscular injection into the lateral thigh 2, 4
• Frequency: Repeat every 5-15 minutes as needed 2, 4
• Example: A 20 kg child receives 0.2 mg (0.2 mL of 1:1000 solution) 5

Cardiac Arrest (Intravenous/Intraosseous Route)

• Initial dose: 0.01 mg/kg of 1:10,000 solution (maximum 0.3 mg initially) 2
• Route: Intravenous or intraosseous 2
• Frequency: Repeat every 3-5 minutes during ongoing arrest 2
• Higher doses: 0.1-0.2 mg/kg (1:1000 solution) may be considered for refractory asystole or pulseless electrical activity 2

Why the Doses Differ

The fundamental difference lies in concentration, route, and physiologic goals:

• Anaphylaxis requires α-adrenergic effects to reverse vasodilation and reduce capillary permeability, but the patient has a perfusing rhythm 2, 6
• Cardiac arrest requires higher doses to achieve adequate coronary and cerebral perfusion pressure during chest compressions when there is no spontaneous circulation 2
• Intramuscular absorption from the thigh provides rapid, sustained plasma levels appropriate for anaphylaxis without the risk of cardiac complications 2, 4

Critical Safety Concern: The 1000-Fold Error Risk

A documented pattern of iatrogenic overdoses occurs when physicians confuse anaphylaxis dosing with cardiac arrest dosing. 1

Common Error Pattern:

• Physician intends to give anaphylaxis dose but administers 1 mg IV push (cardiac arrest dose) 1
• This represents a 10-100 fold overdose depending on patient weight 1
• Results in severe systolic dysfunction, potentially lethal cardiac complications 1

Contributing Factors:

• Both indications use "0.01 mg/kg" in pediatrics, but different concentrations (1:1000 vs 1:10,000) 2
• Need for rapid decision-making in critically ill patients amplifies error risk 1
• Many hospitals lack pre-filled, appropriately labeled IM epinephrine syringes 1

Special Considerations for Anaphylaxis Progressing to Cardiac Arrest

If anaphylaxis causes cardiac arrest, immediately switch to cardiac arrest dosing protocols. 2

• Standard resuscitative measures and immediate epinephrine administration take priority 2
• Use high-dose IV epinephrine with rapid progression: 1-3 mg IV over 3 minutes, then 3-5 mg, then 4-10 mg/min infusion in adults 2
• Pediatric cardiac arrest from anaphylaxis: 0.01 mg/kg (0.1 mL/kg of 1:10,000) every 3-5 minutes, with higher doses (0.1-0.2 mg/kg of 1:1000) for refractory arrest 2
• Prolonged resuscitation efforts are encouraged because outcomes are better in young patients with healthy cardiovascular systems 2

Preventing Medication Errors

Hospitals should stock clearly labeled, pre-filled intramuscular epinephrine syringes that are easily distinguished from IV formulations. 1

• The 1:1000 concentration (1 mg/mL) is for IM use in anaphylaxis 2, 4
• The 1:10,000 concentration (0.1 mg/mL) is for IV use in cardiac arrest 2, 4
• Adult epinephrine auto-injectors deliver 0.3 mg; pediatric auto-injectors deliver 0.15 mg 2
• A 0.1 mg auto-injector is available for patients weighing 7.5-15 kg 3

Key Pitfall to Avoid

Never give IV bolus epinephrine for anaphylaxis unless the patient is in cardiac arrest. 7 If IV access is established and the patient remains in shock (but not arrested), use 0.05-0.1 mg IV (1:10,000) or consider continuous infusion at 5-15 μg/min rather than IM dosing 2, 4. This represents only 5-10% of the cardiac arrest dose and requires close hemodynamic monitoring 2, 4.