On Mythbusters today the build team tested the story that if you don’t remove a nitroglycerin patch before using a defibrillator, the nitro will explode. They basically busted that, but there’s still a warning that you should remove such patches before defibrillation.
I have a conjecture that I want to float. Is there metal in the patch? Like, is there a conductive backing to the patch? If so, could that either cause burns to the chest or interfere with the operation of the defibrillator?
The warning doesn’t say anything about why the patch should be removed, so might this be the real reason, and the myth just grew up to fill the gap?
I have seen burn marks on a small child who was defibrillated using adult paddles that did not form a good seal. We also had a mechanic with enough gas vapor in his shirt and chest hair to ignite when defibrillated.
This is all quite interesting and I wanted to note that the aluminum in these patches is not very obvious (i.e. there’s no overt metallic look or feel to any component of the patch, which actually resembles a bandaid).
In one patch (for estrogen), the aluminum is in the form of aluminum acetylacetonate. Does the fact that the aluminum is bound to an organic partner change its electrical properties?
I guess what I’m trying to say is that the aluminum in these transdermal patches doesn’t seem to resemble the aluminum we’re all familiar with. Can we expect it, therefore, to have properties that are just like those of classic metallic aluminum. If not, perhaps the notion of the aluminum in patches acting like a typical metal conductor of electricity is incorrect which, in turn, might mean that the warning about not placing the defib paddle over the patch is well-intentioned but misguided.
You also want to make sure anyone doing compressions is gloved on a patient using nitro paste, unless you want to have a second patient in a big hurry.
It depends on the nitro patch. The long acting patches, are, like other medication patches, sealed, with a semi-permeable membrane to control the dosage release.
But, nitro can also be applied from a tube with plastic food wrap and tape to hold it in place.
I’ve never seen anyone zap a patient with a nitro patch on, not because it might explode, but because if one needs defibrillation, one is, by definition, hypotensive. The first thing we would do is snatch off the patch, since the nitro contributes to hypotension. Something about defeating the purpose…
An aside: The way to check to see of nitroglycerin pills are still good, is to hit one with a hammer, if it pops like a cap, they’re good.
