Amiodarone has been the first line therapy for VT/VF since 2000. At that time it replaced Lidocaine as the drug of choice, in the resuscitation guidelines. Lidocaine however made a comeback in 2018 and now either is recommended for use. Is one better than the other? Most studies have found that there is no real difference between the two. However most of the studies are for out-of hospital cardiac arrest (OHCA). There is much less in the literature relating to in-hospital cardiac arrest (IHCA).
Should we treat the in-hospital patient differently when they arrest to those who arrest out of hospital? Should the patient who arrests in the resuscitation bay be treated differently to that patient who arrests at home? We don’t really know the answer. This is why looking at this new study (1), is important.
Bottom Line
What they found was that adult patients with IHCA secondary to VT/VF who receive defibrillation and are treated with Lidocaine, have a statistically significant benefit in terms of 24 hour survival and discharge with a favourable neurological outcome.
Will it change our management? Let’s see what they did.
What they did
This is a multicenter prospective registry study, for IHCA.
n= 14630 patients with VT/VF who received either Amiodarone or Lidocaine.
Primary Outcome:
Return of Spontaneous Circulation (ROSC)
Secondary Outcomes:
- 24 hour survival
- Survival to Hospital Discharge
- Discharge with favourable neurological outcome
68.7% of patients received Amiodarone
31.3% of patients receive Lidocaine
Results
Lidocaine was no better than Amiodarone for ROSC, but showed statistically significant improvements over Amiodarone, in survival to discharge and survival with favourable neurological outcome.
My Take on This
This was a registry study and I’m always cautious about interpreting these, as registry studies don’t always give us an accurate representation.
The limitations of this study included:
- Only hospitals participating in the registry were included.
- Much of the data detailing length of CPR and causes of arrest were not available
Lidocaine does have some benefits over Amiodarone:
- It is pre-loaded and ready for use
- It does not have the haemodynamic challenges that can be associated with Amiodarone
- There is some evidence that it is neuroprotective.
Regardless of these, my greatest concern, is that this study found a benefit of Lidocaine over Amiodarone, when other studies have not (2,3).
I’m not sure if this will change my practice. It may be more important to look at Lidocaine as being used for particular causes of VT/VT and Amiodarone for others,. ie., ischaemia versus structural causes.
References
- Wagner D et al. Comparative Effectiveness of Amiodarone and Lidocaine for the Treatment of: In-Hospital Cardiac Arrest. Chest. 2022 Nov 2;S0012-3692(22)04039-9. doi: 10.1016/j.chest.2022.10.024.Online ahead of print
- Ali MU, et al. Effectiveness of antiarrhythmic drugs for shockable cardiac arrest: a systematic review. Resuscitation. 2018;132:63-72.
- Holmberg MJ, et al. American Heart Association’s for the AHA’s Get With The Guidelines!Resuscitation Pediatric Research Task Force. Lidocaine versus amiodarone for pediatric in-hospital cardiac arrest: an observational study. Resuscitation. 2020;149:191-201.
