Lidocaine Dosing During CPR for Refractory VF/pVT
For shock-refractory ventricular fibrillation or pulseless ventricular tachycardia during CPR, administer lidocaine at an initial IV/IO dose of 1.0 to 1.5 mg/kg, followed by a second dose of 0.5 to 0.75 mg/kg if needed. 1
Dosing Algorithm
Initial Dose
- 1.0 to 1.5 mg/kg IV/IO for the first dose 2, 1
- For a 70 kg patient, this translates to approximately 70-105 mg 2
- Administer after failed defibrillation attempts, not as first-line therapy 1
Second Dose (If Required)
- 0.5 to 0.75 mg/kg IV/IO if VF/pVT persists 2, 1
- For a 70 kg patient, this is approximately 35-52.5 mg 2
- Can be given if rhythm remains refractory after continued CPR and defibrillation 1
Clinical Context and Timing
Lidocaine should be considered specifically for VF/pVT that is unresponsive to defibrillation, particularly in witnessed arrests where time to drug administration is shorter. 2 The 2020 American Heart Association guidelines classify this as a Class IIb recommendation, meaning it "may be considered" but is not definitively proven to improve long-term survival or neurological outcomes 2.
When to Administer
- After at least one failed defibrillation attempt 1
- During ongoing CPR cycles (administer during the 2-minute CPR period between rhythm checks) 1
- Epinephrine should be given every 3-5 minutes regardless of antiarrhythmic use 1
Important Safety Considerations
Weight-Based Dosing Rationale
The 2018 AHA guidelines specifically emphasize weight-based dosing for patient safety, despite clinical trials using standardized bolus doses for ease of execution. 2 This approach minimizes the risk of toxicity while maintaining therapeutic efficacy.
Maximum Dosing Limits
- The maximum recommended dose should not exceed 4.5 mg/kg (2 mg/lb) body weight when used without epinephrine 3
- Total dose should be kept below 300 mg in normal healthy adults 3
- These limits are based on FDA labeling for general lidocaine use and should guide total cumulative dosing during resuscitation 3
Evidence Quality and Clinical Nuances
Comparative Effectiveness
Recent evidence suggests lidocaine may actually be superior to amiodarone for in-hospital cardiac arrest, with higher rates of ROSC (adjusted OR 1.15), 24-hour survival (adjusted OR 1.16), survival to discharge (adjusted OR 1.19), and favorable neurological outcomes (adjusted OR 1.18) 4. A 2025 retrospective study of out-of-hospital cardiac arrest also found lidocaine associated with greater odds of prehospital ROSC (36.0% vs 30.4%; aOR 1.29) and survival to discharge compared to amiodarone 5.
Limitations of Evidence
No antiarrhythmic drug has been proven to increase long-term survival or improve neurological outcomes after VF/pVT cardiac arrest. 2 The recommendation for lidocaine is based primarily on modest improvements in short-term outcomes like ROSC and survival to hospital admission in the ROC-ALPS trial 2.
Common Pitfalls to Avoid
Defibrillation Threshold Effects
Lidocaine can acutely elevate the defibrillation threshold, requiring higher energy for successful cardioversion 6. This effect appears to be associated with high blood concentrations (>6 mcg/mL) 7. Continue aggressive defibrillation attempts even after lidocaine administration 1.
Route of Administration
- IV/IO routes are strongly preferred 1
- If endotracheal administration is absolutely necessary (no IV/IO access), doses should be 2 to 2.5 times the IV dose 8
- Endotracheal doses of 400-500 mg are needed to achieve therapeutic plasma levels, while 200-320 mg doses are inadequate 9
Not a Substitute for High-Quality CPR
Lidocaine administration should never delay or interrupt high-quality chest compressions or defibrillation attempts. 1 These remain the primary determinants of survival in cardiac arrest 1.
Practical Implementation
The 2020 AHA Adult Cardiac Arrest Algorithm places lidocaine as an option alongside amiodarone for drug therapy during refractory VF/pVT 1. The choice between the two agents may be influenced by: