What is the recommended dosing of lidocaine (Anti-arrhythmic medication) for a patient in a life-threatening cardiac situation requiring Advanced Cardiovascular Life Support (ACLS) with ventricular tachycardia or fibrillation?

ACLS Lidocaine Dosing for Shock-Refractory VF/pVT

For shock-refractory ventricular fibrillation or pulseless ventricular tachycardia during ACLS, administer lidocaine at 1.0 to 1.5 mg/kg IV/IO as the initial dose, followed by a second dose of 0.5 to 0.75 mg/kg IV/IO if needed. 1

Initial Dosing Protocol

• First dose: 1.0 to 1.5 mg/kg IV/IO 1
• Second dose (if VF/pVT persists): 0.5 to 0.75 mg/kg IV/IO 1
• Maximum cumulative dose: Do not exceed 3 mg/kg total 1

The 2018 American Heart Association guidelines emphasize weight-based dosing for patient safety, despite clinical trials using standardized bolus doses for ease of execution. 1

Clinical Context and Timing

Lidocaine should only be administered for VF/pVT that is unresponsive to defibrillation (shock-refractory). 1 The drug is particularly useful for patients with witnessed arrest, where time to drug administration is shorter and outcomes may be improved. 1

Critical Priority Sequence:

• CPR and defibrillation remain the primary interventions associated with improved survival 1
• Establishing vascular access for drug administration should never compromise CPR quality or timely defibrillation 1
• Lidocaine facilitates successful defibrillation and reduces recurrent arrhythmias but does not pharmacologically convert VF/pVT alone 1

Evidence Strength and Limitations

The recommendation for lidocaine carries a Class IIb designation (may be considered) with Level of Evidence B-R, meaning the benefit is not definitively established. 1

Important evidence considerations:

• No antiarrhythmic drug has demonstrated improved long-term survival or favorable neurological outcomes after VF/pVT cardiac arrest 1
• The ROC-ALPS trial showed lidocaine improved survival to hospital admission compared to placebo, and improved survival to discharge in witnessed arrests 1, 2
• Lidocaine and amiodarone showed no significant difference in survival rates (23.7% vs 24.4%, p=0.70) 2

Amiodarone vs Lidocaine Decision

Either amiodarone or lidocaine may be used—the choice depends primarily on availability and institutional familiarity. 1

• Amiodarone dosing: 300 mg IV/IO initial dose, followed by 150 mg IV/IO if needed 1
• Lidocaine advantage: Fewer immediate side effects and widespread familiarity among healthcare providers 1
• Amiodarone consideration: Requires polysorbate-based formulation for rapid administration during arrest; captisol-based formulation is impractical 1

Recent evidence from in-hospital cardiac arrest suggests lidocaine may have slightly better outcomes than amiodarone (survival to discharge: AOR 1.19, p<0.001), though this conflicts with out-of-hospital data showing equivalence. 3, 2

Common Pitfalls to Avoid

Do not use lidocaine routinely or prophylactically during cardiac arrest—it is only indicated for shock-refractory VF/pVT. 1

Do not delay defibrillation to establish IV access for lidocaine—this is a critical error that worsens survival. 1

Do not confuse lidocaine's role—it does not control heart rate and should never be used for atrial fibrillation or flutter requiring rate control. 4

Do not use standard doses in heart failure or shock patients without significant reduction—lidocaine clearance is substantially decreased and half-life increases to >20 hours in heart failure. 5

Route of Administration

Both intravenous (IV) and intraosseous (IO) routes are acceptable for lidocaine administration during cardiac arrest. 1 The IO route has been used anecdotally without known adverse effects, though experience is more limited than with IV administration. 1