A cardiac arrest is in progress. CPR is ongoing and the team needs a rapid calculation of the correct adrenaline dose, the amiodarone dose for a shockable rhythm and the volume to draw up from the available stock concentrations before the next rhythm check.
Adrenaline: 1 mg IV/IO every 3–5 min (1:10,000 — 10 mL)
Amiodarone: 300 mg IV/IO bolus after 3rd shock · 150 mg after 5th
Atropine: 3 mg IV/IO (single dose for asystole/PEA — not routine in ALS)
Paediatric adrenaline: 0.01 mg/kg IV/IO (max 1 mg)
Paediatric amiodarone: 5 mg/kg IV/IO (max 300 mg)
1 What this calculator does
Calculates indicative cardiac arrest drug doses for adrenaline (epinephrine), amiodarone and atropine based on patient weight. Distinguishes adult (>=40 kg) and paediatric (<40 kg) dosing. Shows the volume to draw from standard prehospital stock concentrations. All values are for reference only -- follow current ARC/AHA guidelines and agency protocol.
2 Formula & professional reasoning
Adrenaline (epinephrine):
Adult: 1 mg fixed dose -> 10 mL of 1:10,000 (0.1 mg/mL) IV/IO
Paediatric: 0.01 mg/kg -> volume = 0.01 x weight / 0.1 mL of 1:10,000 | Repeat every 3-5 min
Amiodarone:
Adult: 300 mg fixed -> 6 mL of 50 mg/mL IV/IO (after 3rd shock)
Paediatric: 5 mg/kg -> volume = 5 x weight / 50 mL of 50 mg/mL
Atropine:
Adult: 3 mg fixed (max)
Paediatric: 0.02 mg/kg (max 3 mg)
All doses: follow current ARC/ILCOR/AHA guidelines. Confirm with medical direction.
Adult cardiac arrest drug doses are fixed (not weight-based) because variability in adult weight does not significantly change the required dose for the physiological effect targeted. Paediatric doses are weight-based because the range of paediatric weights (3-40 kg) produces clinically significant dose differences. Adrenaline in 1:10,000 concentration (0.1 mg/mL) gives a 10 mL volume for the adult 1 mg dose, making it easy to measure accurately under stress. Amiodarone is given as a bolus for VF/pVT after the third shock, based on the ARREST and AMIO-CAT trials.
3 Worked examples
⚠️ Illustrative example only — not clinical or professional instruction.
Adrenaline: adult fixed 1 mg | Volume: 1/0.1 = 10 mL of 1:10,000 | Amiodarone: adult fixed 300 mg | Volume: 300/50 = 6 mL of 50 mg/mL | Atropine: adult max 3 mg | Volume: 3/0.6 = 5 mL of 600 mcg/mLAdrenaline: 0.01 mg/kg x 18 = 0.18 mg | Volume: 0.18/0.1 = 1.8 mL of 1:10,000 | Amiodarone: 5 mg/kg x 18 = 90 mg | Volume: 90/50 = 1.8 mL of 50 mg/mLFirst adrenaline: given at 3-5 min after first non-shockable rhythm confirmed (or after 3rd shock for shockable) | Second adrenaline: 3-5 min after first | IO route: same dose and concentration as IV | Flush after each drug: 20 mL normal saline flush4 Sanity check
5 Common errors
| Error | Cause | Consequence | Fix |
|---|---|---|---|
| Confusing 1:1,000 and 1:10,000 adrenaline concentrations | Both concentrations are carried on many EMS units for different indications | Administering 1:1,000 (10x concentration) IV in cardiac arrest volume = 10-fold overdose | Or administering 1:10,000 IM for anaphylaxis = one-tenth of the therapeutic dose | 1:10,000 adrenaline (0.1 mg/mL) is the concentration for IV/IO cardiac arrest use. 1:1,000 adrenaline (1 mg/mL) is the concentration for IM use in anaphylaxis. Always read the concentration on the ampoule label before drawing up. Both clinicians confirm the concentration. |
| Interrupting CPR to administer drugs via peripheral IV without flush | Prioritising drug administration over CPR quality | Drug does not reach central circulation -- loss of therapeutic effect | Compromised CPR quality | Drugs should be administered with minimal CPR interruption. Use IO access if IV is not yet established. Follow each drug with a 20 mL saline flush to drive it centrally. CPR quality (rate and depth) must not be compromised for drug administration. |
| Not verifying paediatric drug calculations independently with the second clinician | Time pressure during cardiac arrest | Paediatric dose error -- small weight differences have proportionally larger dose effects than in adults | All paediatric cardiac arrest drug calculations require independent double-check by the second clinician before administration. Use the Broselow tape or Paeds Weight Estimator to confirm the weight estimate. Read the calculated dose and volume aloud before drawing up. |
| Giving amiodarone for non-shockable rhythms (PEA, asystole) | Reaching for amiodarone in any refractory cardiac arrest | No benefit for non-shockable rhythms and potential adverse effects without therapeutic indication | Amiodarone (and lidocaine as an alternative) is indicated for refractory ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT) -- shockable rhythms that have not responded to 3 defibrillation attempts. For PEA and asystole, focus on reversible causes (4Hs and 4Ts) and adrenaline. |
6 Reference & regulatory links
7 Professional workflow
Common tools used alongside this one: