THE REAL-WORLD BOARDS: Question #1
An 82-year-old woman in refractory V-fib arrest arrives in the E.D. Your move.
These are the Real-World Boards. As in the real world, there might be no single right answer, and you are only competing against yourself. Please share your experiences, discuss and critique this question below. Good luck! -Ed.
An 82-year-old woman is brought from a nursing home by EMS to the emergency department in ventricular fibrillation. She was found unresponsive about 15 minutes ago after an unknown period. Chest compressions were begun on site immediately and were continued throughout transport. Pre-hospital, she received ACLS-guided resuscitation with regular epinephrine injections and at least 5 shocks, first by the on-site AED and then by EMS, delivering 200 joules by a biphasic defibrillator.
Your emergency medicine colleague has continued high-quality CPR and epinephrine and delivered three additional shocks, escalating to 300 J and then 360 J in the E.D.
Amiodarone (300 mg and then 150 mg IV) was given. The original pads’ correct anterolateral position and function were confirmed.
She remains in ventricular fibrillation. There have been no ST-elevations noted and no morphology to suggest torsades de pointes. No reversible causes have been identified on labs or exam. Approximately 20 minutes have elapsed since the initiation of CPR. Attempts to reach the family have been unsuccessful. The patient is in a “full code” status.
By telephone, the on-call cardiologist recommended against left heart catheterization due to the predicted poor outcome even if occlusions were found and revascularization were to permit defibrillation.
Your emergency medicine colleague asks your opinion on what to do next.
Physicians receive no formal guidance on how long to perform CPR. Although the median duration is ~20-25 minutes in the U.S., this masks a wide variability that is influenced by multiple poorly understood factors: the culture at the institution; the physician’s habits acquired in training; her personal values and religious beliefs; perception of a patient’s life expectancy and expected outcome, and more.
Refractory ventricular fibrillation poses unique challenges to the treating physician. Unlike the non-shockable rhythms (asystole and pulseless electrical activity), VF is often due to reversible causes, and patients overall have better outcomes when the arrhythmia is terminated.
All other things being equal, therefore, it is reasonable to take a more aggressive or “heroic” approach to treating refractory VF, as compared to asystole or PEA.
After all, a resuscitation failure is equivalent to death. Yet the very term aggressive implies an edge of extremity, a risk of harm. And most of the improvement in outcomes with shockable rhythms comes when they are terminated early.
Can one go too far while treating a cardiac arrest?
Dual Sequential Defibrillation
Dual sequential defibrillation involves delivering two defibrillation shocks in rapid sequence using two defibrillators, each connected to its own set of pads. Double sequential external defibrillation (DSED) is another moniker.
For a patient already undergoing resuscitation, a second set of defibrillator pads is placed in a different vector (e.g. anterior-posterior) than the existing set of pads (usually in the standard anterolateral vector).
Both defibrillators are charged to maximum energy (usually 200 J on biphasic devices, but possibly higher), and the two shocks are delivered in very quick succession (e.g., ~10 milliseconds apart, but not perfectly simultaneously).
Shocking more myocardium in more than one vector could theoretically terminate VF more effectively than a single vector.
In the DOSE VF trial (Cheskes et al, NEJM 2022), patients with refractory VF randomized to dual sequential defibrillation had greater survival to hospital discharge and improved neurologic outcomes compared to conventional defibrillation. DSD was administered by EMS in the pre-hospital setting. The trial was stopped at about half the intended enrollment due to the Covid-19 pandemic.
The American Heart Association’s 2020 ACLS guidance gave a 2b recommendation for DSD (“may / might be considered”), citing a 2020 systematic review by ILCOR that found insufficient evidence to support DSD.
AHA expressed concerns about proper implementation and potential for harm to patients or damage to defibrillators, stating:
“It is premature for double sequential defibrillation to be incorporated into routine clinical practice given the lack of evidence. Its usefulness should be explored in the context of clinical trials.”
Notably, the DOSE VF trial had not yet been published at that time.
ILCOR (which advises AHA and similar societies) gave a weak recommendation for DSD for refractory VF/VT in a 2023 statement (after the publication of DOSE VF).
A randomized trial in Norway testing DSD for VF with an intended enrollment of 356 patients is underway, according to clinicaltrials.gov.
Video by EM:RAP via YouTube provided here for informational purposes only. -Ed.
Stellate Ganglion Block
Some refractory VF is caused or exacerbated by excessive autonomic (sympathetic) nervous system activity, called electrical storm.
In a stellate ganglion block, local anesthetic is injected near the stellate ganglion, a collection of sympathetic nerves located in the neck (at the level of the C6 or C7 vertebra). SGB has an established role in the treatment of chronic pain; anesthesia and pain specialists may perform the block when sympathetic activity is believed to be worsening a patient’s pain syndrome.
SGB has also been used experimentally as a treatment for refractory shockable rhythms (ventricular tachycardia and ventricular fibrillation). Blocking the stellate ganglion reduces sympathetic outflow to the heart, potentially reducing arrhythmogenic triggers.