Preparing 1:10,000 Adrenaline for Cardiac Arrest vs. Anaphylaxis
Critical Distinction: DO NOT Prepare 1:10,000 for Anaphylaxis
For anaphylaxis, you should NEVER dilute your 1:1000 ampule to 1:10,000 concentration—use the 1:1000 concentration intramuscularly as supplied. 1, 2 The 1:10,000 dilution is exclusively for intravenous use in cardiac arrest, not for anaphylaxis treatment. 1, 3
Patient 1: Cardiac Arrest
Preparation of 1:10,000 Solution
- Take 1 mL of 1:1000 adrenaline (1 mg) and dilute it with 9 mL of normal saline to create 10 mL of 1:10,000 solution (0.1 mg/mL). 1
- Each 1 mL of this diluted solution now contains 0.1 mg (100 mcg) of adrenaline. 1
Dosing for Cardiac Arrest
- Administer 1 mg (10 mL of 1:10,000 solution) intravenously every 3-5 minutes during ongoing cardiac arrest. 1, 4
- For refractory cardiac arrest, consider escalating to 3-5 mg administered intravenously over 3 minutes, followed by 4-10 mg/min infusion if needed. 1
- Prolonged resuscitation efforts are encouraged in anaphylaxis-induced cardiac arrest, as patients are often young with healthy cardiovascular systems. 1
Patient 2: Anaphylaxis (NOT in Cardiac Arrest)
DO NOT Dilute—Use 1:1000 Intramuscularly
- Administer 0.5 mL of 1:1000 adrenaline (0.5 mg) intramuscularly into the vastus lateralis (anterolateral thigh) immediately. 1, 2
- The intramuscular route achieves peak plasma concentrations in 8±2 minutes compared to 34±14 minutes with subcutaneous injection. 2
- Repeat the same dose every 5 minutes if symptoms fail to resolve or worsen. 2
- There is no maximum number of intramuscular doses—continue every 5 minutes until symptoms resolve, with most patients requiring 1-2 doses but some needing more. 2
When to Consider Intravenous Adrenaline in Anaphylaxis
- Only consider intravenous adrenaline if the patient fails to respond to multiple intramuscular doses and has severe refractory hypotension or bronchospasm. 1, 5
- If intravenous administration is necessary, use 50 mcg (0.5 mL of 1:10,000 solution) as an initial adult dose, titrated carefully to response. 1
- Intravenous adrenaline carries significant risk of dilution/dosing errors and serious cardiac adverse effects—the intramuscular route is safer and preferred for first-line treatment. 2, 3
Critical Safety Points
Common Fatal Error to Avoid
- Never administer 1:1000 concentration intravenously—this represents a 10-fold overdose and can cause severe cardiac complications including ventricular arrhythmias, myocardial dysfunction, and death. 3, 6
- Confusion between 1:1000 (for IM use) and 1:10,000 (for IV use) is a well-documented cause of iatrogenic overdose. 3
- Clearly label all syringes with concentration, route, and indication to prevent medication errors. 3
Concurrent Management for Anaphylaxis
- Position the patient supine with legs elevated—never allow standing or walking, as this increases mortality risk. 2
- Administer normal saline bolus of 1000-2000 mL for adults with hypotension. 2
- Call for emergency assistance immediately, even if symptoms initially improve. 2
- Consider adjunctive therapy with antihistamines (chlorphenamine 10 mg IV) and corticosteroids (hydrocortisone 200 mg IV) after adrenaline administration. 1
Monitoring Requirements
- For intravenous adrenaline administration, monitor blood pressure and pulse every minute with continuous electrocardiographic monitoring if available. 1
- Watch for signs of excessive vasoconstriction including cold extremities and decreased urine output. 7
Summary Algorithm
Cardiac Arrest Patient:
- Dilute 1 mL of 1:1000 adrenaline with 9 mL saline → 10 mL of 1:10,000
- Give 10 mL (1 mg) IV push every 3-5 minutes
- Continue until return of spontaneous circulation
Anaphylaxis Patient (NOT in arrest):
- DO NOT dilute—use 1:1000 as supplied
- Give 0.5 mL (0.5 mg) IM into thigh immediately
- Repeat same dose every 5 minutes if needed
- Only consider IV route if multiple IM doses fail (use 1:10,000 dilution, 50 mcg initial dose)