Defibrillation and nipple rings

[chipco3434]

Went for recert tonight on CPR+AED. The question came up regarding nipple rings and the possible outcomes of leaving them "installed" during a cycle of the defibrillator.

The instructor was advised by doctors that they should be removed. Due to the nature of such emergencies, the suggested method is a two step process: 1) twist; 2) pull.

Always in these situations there's somebody in the crowd...

"What if it's a non-metalic metal?"

Back to the question at hand. What would one expect the result of a small piece of jewelry in the path of a 200-300 joule discharge through the chest. For those that may not be familiar, the pads are placed at 12 o'clock on the right nipple and 5 o'clock south of the left nipple.

My best guess, a small arc, maybe some burns. Next guess would be no effect.

[Puggie]

Well I know someone whe didn't have their nipple rings removed before being defibbed and she is very grateful to be alive but she has suffered quite severe burns and nerve damage from the zap, her nipples were burned and blistered quite badly. I have also seen pics of a necklace being left on (thin gold chain) and that left a good blister/welt around the neck.

Nicotine anit smoking patches are good, they explode if you don't remove them first

[pinkmouse]

Can someone explain the mechanism of this? I thought defibrillators used high voltage, low current. I can see this happening with high current low voltage, but the other way around? I will have to ask that rather pretty nurse who works in Kings College ICU I was introduced to the other day...

[EC8010]

I understand that the defibrillators have settings marked in Joules of work done, sometimes going up to 300J. That's an awful lot of urge, and you know what happens if you accidentally short a power supply capacitor...

Considering the "two-step process" (yikes!), I can't help feel that doctors should be issued with wire cutters rather than ripping sensitive bits.

[chipco3434]

There generally aren't any user defined settings on the "A" ED's. That's what makes them "A", automated. The pads, adult or child, either set the energy level (keyed connector) or have a big R in the cables for the kid's size. Kids get 60 joules. Old AED's were about 200 joules. New ones are 275 to 300. From what I understand, the new ones start at ~200 then increase to 250 and 300 if they fail to cardiovert fib or v-tach.

All the new ones are biphasic. I reckon this is +/- rather than a big +/0 wave.

[jacco vermeulen]

Next you can contemplate on what happens if someone ends up in an MRI-NMR scanner and forgot to take off the nipple rings.

(that's odd, howcome i have these sudden images of the Hellraiser movie popping up)

[Tweeker]

NMRI rooms are good candidates for metal detectors. Steel oxygen tanks are a particular suspect.

there have been several MRI accidents, some of them fatal, involving metal objects as small as paper clips, Dr. Kanal said. One woman who underwent an MRI died because of an implanted aneurysm clip in her brain.

Another who forgot to pull a hairpin out of her hair required a procedure to extract the hairpin after the pin traveled up her nose and lodged in her pharynx. And in Rochester last year, an MRI magnet pulled a .45-caliber gun out of the hand of a police officer and the gun shot a round that lodged in a wall.

[Eva]

Defibrilator pad surface is plain conductive flat metal sheet, isn't it?

Piercings are either plain conductive metal as the defibrilator pads or non-conductive. Nothing should go wrong here. The pads have a far lower impedance contact with the body than any small piercing. Also, a cream is used to wet the skin and make it very conductive, as very dry skin is a good insulator, isn't it?

Twist and pull? Damn, only a doctor could have figured out that

[Fuling]

http://www.bmezine.com/news/edit/A30727/artbodyp.html

[jneutron]

Originally posted by pinkmouse
Can someone explain the mechanism of this? I thought defibrillators used high voltage, low current. I can see this happening with high current low voltage, but the other way around?

Body resistance is about 150 ohms for the defib calcs, but varies a bit. Defib design has to accomodate that.

If you examine the current delivery, you would see that the current spikes anywhere from 15 amperes to 35 amperes, depending on the skin resistance, energy level, and mono/biphasic.

35 amperes??? Holy mackeral. Through a nipple!!!! (ouch)

The recommended paddle pressure is in the 25 pound range. If a nipple ring made the person NOT press hard enough to obtain good contact(fear of harm maybe?), then more of the current would travel via the ring, as that would be the path of less resistance. I make the assumption that that would not feel nice..

Originally posted by pinkmouse

I will have to ask that rather pretty nurse who works in Kings College ICU I was introduced to the other day...

Well?? Or, did you forget to ask, perhaps something else on you mind??

Cheers, John

ps...where's my manners?? Here's a link. If you look at figure 7 and 8, you can see the currents they are talking about. I wish the graphs were less fuzzy, but hey,,,I got what I paid for..

http://www.medical.philips.com/main/...rm_design.html