» Grady Report

Lit of the Week – 4/12/16

Clinical question / background:

Compared to placebo, does administration of amiodarone or lidocaine improve mortality or neurologic outcome in patient’s with out-of-hospital cardiac arrest due to ventricular fibrillation or pulseless ventricular tachycardia?

Design:

Randomized, double-blind, placebo-controlled trial at 10 North American centers
3026 patients with out-of-hospital cardiac arrest
- 974 amiodarone group
- 993 lidocaine group
- 1059 placebo group
Inclusion: Adults (> 18 y/o) with non-traumatic, shock-refractory VFib or pulseless VTach + IV or IO access
- Shock refractory = delivered 1 or more shock during resuscitation
Exclusion: already received Amiodarone or Lidocaine OR known hypersensitivity to these drugs
Normal pre-hospital cardiac arrest care + administration of study drugs or placebo
Primary outcome: survival to hospital discharge
Secondary outcomes: survival with favorable neurologic status at discharge defined as MRS < 3 (conduct ADLS independently or with minimal assistance)

Intervention:

Lidocaine IV
- Initial dose of 120 mg IV (60 mg if patient less than 100 lb)
- Second dose of 60 mg IV if first dose unsuccessful
Amiodarone IV
- Initial dose 300 mg IV (150 mg if patient < 100 lb)
- Second dose of 150 mg IV if first dose unsuccessful

Control:

Results:

No significant demographic differences between three groups
No significant difference in survival to hospital discharge for Amiodarone vs Placebo (24.4% vs 21%), Lidocaine vs Placebo ( 23.7% vs 21%), or Amiodarone vs Lidocaine (24.4% vs 23.7%)
- Absolute risk difference between each groups also not significant
No significant difference in survival with favorable neurologic status for amiodarone vs placebo (18.8% vs 16.6%), lidocaine vs placebo (17.5% vs 16.6%), and amiodarone vs lidocaine (18.8% vs 17.5%)
Witnessed arrest à rate of survival to hospital discharge was significantly higher with amiodarone (27.7%) or lidocaine (27.8%) than with placebo (22.7%) — a clinically important difference of 5 percentage points

Take-home:

neither amiodarone nor lidocaine resulted in a significantly higher rate of survival or favorable neurologic outcome than the rate with placebo among patients with out-of-hospital cardiac arrest due to initial shock-refractory ventricular fibrillation or pulseless ventricular tachycardia
Consider administration of Amiodarone or Lidocaine in witnessed arrests
Bystander CPR still offers best outcomes regardless of drug used

Strengths:

Well-designed, double-blinded large trial
Although not primary outcomes: trial observed the following
- Fewer shocks administered after study drugs given
- Fewer patents required rhythm-control medications during hospitalization in study groups
- Fewer patients required CPR during hospitalization if they had ROSC

Lit of the Week — Amiodarone, Lidocaine, or Placebo in out-of-hospital cardiac arrest