ACLS Lidocaine Dosing for Cardiac Arrest
The recommended ACLS dose of lidocaine for shock-refractory VF/pVT is an initial dose of 1-1.5 mg/kg IV/IO, followed by a second dose of 0.5-0.75 mg/kg if needed. 1
Dosing Protocol for Lidocaine in ACLS
Initial Administration
- First dose: 1-1.5 mg/kg IV/IO bolus
- Second dose: 0.5-0.75 mg/kg IV/IO if needed
Clinical Context
Lidocaine is now considered equivalent to amiodarone as a first-line antiarrhythmic agent for shock-refractory ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT) according to the 2018 American Heart Association guidelines. This represents a change from previous guidelines which favored amiodarone as the first-line therapy 1.
Mechanism and Indications
Lidocaine is a Class Ib antiarrhythmic agent that:
- Acts by blocking sodium channels with rapid kinetics
- Is particularly effective in ischemic or depolarized tissue
- Has minimal effect on normal cardiac tissue 2
Lidocaine is indicated in ACLS for:
- Persistent VF/pVT despite defibrillation and epinephrine
- Prevention of recurrence of VF/pVT
- Control of unsustained ventricular ectopy requiring therapy
- Treatment of wide-complex tachycardia of uncertain type 1
Important Considerations
Safety Concerns
- Lidocaine is metabolized in the liver and its clearance is reduced in heart failure 1
- Exceeding maximum recommended doses can lead to toxicity, including seizures 3
- Careful dosing is particularly important in patients with hepatic dysfunction, advanced age, or hemodynamic compromise
Efficacy Considerations
While lidocaine is recommended in current ACLS protocols, it's important to note that:
- CPR and defibrillation remain the only therapies consistently associated with improved survival in VF/pVT 1
- Antiarrhythmic medications primarily show benefits in short-term outcomes such as ROSC or survival to hospital admission 1
- The optimal sequence and timing of ACLS interventions, including antiarrhythmic administration, remains uncertain 1
Administration in the ACLS Algorithm
Lidocaine should be administered:
- After defibrillation attempts have failed to convert VF/pVT
- After epinephrine has been administered
- Before or after the third shock in persistent or recurrent VF/pVT
- Via IV or IO route when available
Remember that high-quality CPR with minimal interruptions and early defibrillation for shockable rhythms remain the cornerstones of effective resuscitation, with medications playing a supportive role in the ACLS algorithm.