Cardiac & Resuscitation, Columns

Are AED Shocks Safe During Hands-On Compressions?

Issue 11 and Volume 41.

The Research

Wampler D, Kharod C, Bolleter S, et al. A randomized control hands-on defibrillation study—Barrier use evaluation. Resuscitation. 2016;103:37–40.

The Science

The authors of this study decided to test previous research that indicated there’s no leakage of energy through the gloved hand compressing on the chest during defibrillation in a more scientific manner.

They placed a partition between the CPR provider and two automated external defibrillators (AEDs), one of which was connected to non-embalmed fresh cadavers with standard AED pads and the other connected to a test load. The CPR provider was randomly assigned to compress the chest either bare-handed, wearing either a single layer or double layer of nitrile gloves, bare-handed over a neoprene pad, wearing firefighter gloves, or while using a manual CPR device (ResQPUMP).

They then randomly defibrillated the cadaver with 360 J or dumped the charge into the test load. They only used 30 J for bare-handed CPR. The CPR provider was asked to indicate whether or not they felt the shock and rate its severity on a scale from 1–10.

Of the 10 subjects who performed CPR, all detected the 30 J shocks during bare-handed compressions. Of the 500 shocks delivered during the experiment, five (1%) of the real shocks were detected: one while wearing the single layer of nitrile gloves, three with the double-layer nitrile gloves and with the neoprene pad. No shocks were detected with the fire gloves or the CPR device. All the shocks that were detected were characterized as barely perceptible (less than 1 on the scale).

Doc Wesley Comments

Well, this study confirms my suspicions. A single pair of gloves, or double layer if you want to go the belt-and-suspenders approach, will insulate you from the defibrillation.

I remember the good old days of the LifePak 5 where we placed the gel on the metal electrodes, rubbed them together and then applied them to the patient’s chest, pressing down while yelling “clear!” and pushing that little red button on the handle.

Yeah, those were the days—when we were told to wipe away the nitro paste from the chest out of fear of an explosion during defibrillation. When we had to make sure that the patient wasn’t on a wet metal catwalk that would shoot the joules into our bodies and throw us across the room. When we had to pull the ambulance over to analyze the rhythm lest we fall onto the patient and electrocute ourselves. Yeah, those were the days.

But those days are gone. Now we have biphasic defibrillators that connect to the patient with adhesive pads. Now we know any time off the chest reduces the effectiveness of the shock. Now we know that we can defibrillate a patient in the snow and use an AED to analyze them in a boat or a moving ambulance. Now we know that we can continue to perform CPR while the defibrillator charges and shocks the patient. All we have to do is wear gloves.

Medic Wesley Comments

Well we know time off the chest in CPR affects the outcome and must be limited. This study gives the opportunity to eliminate a large chunk of the time we spend not performing chest compressions.

I think it’s great we’re constantly looking at improving outcomes in cardiac arrest. This study had a large sample group, and that was important. It meant the volunteer subjects weren’t harmed when defibrillating bare-handed or with one layer of nitrile glove.

But as far as science, I think there could’ve been a safer path to determine whether or not rescuers were affected by the defibrillation energy crossing a patient’s chest.

There are specific safety companies such as Underwriters Laboratory that could provide a more accurate means to determine the efficacy of hands-on CPR during defibrillation. And actually, I’m surprised that approach hasn’t already been taken.

The lack of the “These are trained professionals. Do not try this at the station or in a classroom” statement has me concerned. I’m already aware of some who’ve decided to trial this on their own, sans the physicians. And while the participants signed waivers and there was a resuscitation team on hand, it still seems too early to adopt.

OK, so I’m the wet blanket on this one. Usually Doc takes that role. Call me old-fashioned. Say I think too much like a mom. I just think we need more evidence that it’s safe.

Study Author Craig Manifold, MD, Comments

Although we feel hands-on defibrillation is safe under appropriate conditions, we can’t currently assure it in our field environment. As a medical director, I don’t mandate this method of defibrillation but certainly hope additional studies are undertaken. I do recommend caution if you choose to perform hands-on defibrillation. Additional research, training and appropriate patient/condition selection will help identify when this technique is appropriate.