European Resuscitation Council (ERC) and Resuscitation Council UK Guidelines:
standard protocols for the management of cardiac arrest. The primary drugs recommended include epinephrine (adrenaline), amiodarone, lidocaine (as an alternative to amiodarone), magnesium sulfate (for torsades de pointes- is a type of polymorphic ventricular tachycardia characterised by oscillatory changes in amplitude of the QRS complexes around the isoelectric line ), and occasionally atropine (in specific cases of bradyasystolic arrest)
1. Epinephrine (Adrenaline)
Indications:
- Used in all cardiac arrest situations, including both shockable rhythms (ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT)) and non-shockable rhythms (asystole and pulseless electrical activity (PEA)).
Dosage:
- Adult: 1 mg IV/IO every 3-5 minutes during resuscitation.
Mechanism:
- Epinephrine stimulates alpha-adrenergic receptors, causing vasoconstriction and increasing coronary and cerebral perfusion pressures during CPR. It also stimulates beta-adrenergic receptors, which can increase heart rate and myocardial contractility.
Administration:
- For non-shockable rhythms (asystole and PEA), administer epinephrine as soon as possible after starting CPR.
- For shockable rhythms (VF/pulseless VT), administer epinephrine after the second defibrillation attempt and continue every 3-5 minutes if the rhythm persists.
Key Points:
- Ensure high-quality CPR with minimal interruptions when administering medications.
- Epinephrine is a cornerstone of advanced cardiac life support (ACLS) protocols.
2. Amiodarone
Indications:
- Used for shockable rhythms (VF and pulseless VT) that are unresponsive to initial defibrillation attempts.
Dosage:
- Adult: Initial dose of 300 mg IV/IO bolus. If VF/pulseless VT persists, a second dose of 150 mg IV/IO can be administered.
Mechanism:
- Amiodarone is an antiarrhythmic medication that prolongs the action potential and refractory period in myocardial tissue, stabilizing the heart’s rhythm and preventing reentrant arrhythmias.
Administration:
- Administer the initial 300 mg bolus after the third defibrillation attempt if the rhythm remains shockable.
- If the patient remains in VF/pulseless VT, administer a second dose of 150 mg IV/IO.
Key Points:
- Monitor for potential side effects, such as hypotension and bradycardia.
- Consider a maintenance infusion of amiodarone if return of spontaneous circulation (ROSC) is achieved.
3. Lidocaine
Indications:
- An alternative to amiodarone for shockable rhythms (VF and pulseless VT) if amiodarone is not available.
Dosage:
- Adult: Initial dose of 1-1.5 mg/kg IV/IO bolus, followed by additional doses of 0.5-0.75 mg/kg IV/IO every 5-10 minutes, up to a maximum cumulative dose of 3 mg/kg.
Mechanism:
- Lidocaine stabilises the neuronal membrane by inhibiting ionic fluxes required for the initiation and conduction of impulses, reducing automaticity and excitability of the heart.
Administration:
- Administer the initial bolus of 1-1.5 mg/kg IV/IO.
- If VF/pulseless VT persists, administer additional doses of 0.5-0.75 mg/kg IV/IO at 5-10 minute intervals, not exceeding a total dose of 3 mg/kg.
Key Points:
- Monitor for signs of lidocaine toxicity, including CNS effects and cardiovascular instability.
- Avoid combining with amiodarone.
4. Magnesium Sulfate
Indications:
- Recommended for cardiac arrest due to torsades de pointes (a form of polymorphic VT) or suspected hypomagnesemia.
Dosage:
- Adult: 1-2 grams IV/IO over 5-20 minutes.
Mechanism:
- Magnesium sulfate acts as a calcium antagonist, stabilising cell membranes and reducing the influx of calcium, which is particularly effective in treating torsades de pointes.
Administration:
- Administer 1-2 grams IV/IO over 5-20 minutes if torsades de pointes is identified or suspected during cardiac arrest.
Key Points:
- Particularly effective in patients with known magnesium deficiency.
- Monitor for side effects such as hypotension and respiratory depression.
5. Atropine
Indications:
- Historically used for bradycardia and asystole, but current guidelines recommend against its routine use in cardiac arrest, except in specific cases of bradyasystolic arrest with profound bradycardia.
Dosage:
- Adult: 1 mg IV/IO, repeat every 3-5 minutes if needed, up to a maximum of 3 mg.
Mechanism:
- Atropine blocks the effects of the vagus nerve on the heart, increasing heart rate by inhibiting parasympathetic stimulation.
Administration:
- Administer 1 mg IV/IO every 3-5 minutes, up to a total of 3 mg, in cases of bradyasystolic arrest with significant bradycardia.
Key Points:
- Not routinely recommended for cardiac arrest.
- Mainly used for symptomatic bradycardia outside of cardiac arrest scenarios.
6. Sodium Bicarbonate
Indications:
- Used in cases of metabolic acidosis, hyperkalemia, or tricyclic antidepressant overdose during cardiac arrest.
Dosage:
- Adult: 1 mEq/kg IV/IO bolus.
Mechanism:
- Sodium bicarbonate buffers excess hydrogen ions, helping to correct metabolic acidosis and stabilize the cardiac cell membrane.
Administration:
- Administer 1 mEq/kg IV/IO bolus in specific situations such as severe acidosis, hyperkalemia, or overdose with tricyclic antidepressants.
Key Points:
- Use is limited to specific situations as guided by clinical and laboratory findings.
- Routine use is not recommended due to potential adverse effects such as alkalosis and hypernatremia.
Summary Table
| Medication | Indications | Dosage (Adult) | Mechanism | Key Points |
|---|---|---|---|---|
| Epinephrine | All cardiac arrest rhythms | 1 mg IV/IO every 3-5 minutes | Alpha and beta-adrenergic agonist; increases coronary and cerebral perfusion | Administer immediately in asystole/PEA, after second shock in VF/pulseless VT |
| Amiodarone | VF/pulseless VT | 300 mg IV/IO bolus, second dose 150 mg if needed | Prolongs action potential and refractory period | Use after third shock if VF/pulseless VT persists |
| Lidocaine | VF/pulseless VT (alternative to amiodarone) | 1-1.5 mg/kg IV/IO, additional doses 0.5-0.75 mg/kg every 5-10 minutes, max 3 mg/kg | Stabilizes neuronal membrane, reduces excitability | Alternative to amiodarone |
| Magnesium Sulfate | Torsades de pointes, hypomagnesemia | 1-2 grams IV/IO over 5-20 minutes | Calcium antagonist; stabilizes cell membranes | Use in torsades de pointes, known magnesium deficiency |
| Atropine | Specific bradyasystolic arrest cases | 1 mg IV/IO, repeat every 3-5 minutes (max 3 mg) | Inhibits parasympathetic stimulation | Not routinely recommended |
| Sodium Bicarbonate | Metabolic acidosis, hyperkalemia, tricyclic overdose | 1 mEq/kg IV/IO bolus | Buffers excess hydrogen ions | Limited use in specific situations |
Important Considerations
- Medication Timing: Timely administration of medications is critical during cardiac arrest. Follow the guidelines for the specific timing of each drug.
- Route of Administration: IV (intravenous) or IO (intraosseous) routes are preferred for rapid drug delivery.
- Reversible Causes: Always consider and treat reversible causes of cardiac arrest (Hs and Ts).
By adhering to these detailed guidelines for medication administration during cardiac arrest, healthcare providers can improve the chances of successful resuscitation and enhance patient outcomes.