DH and I were talking about a CPR class he had taken years ago, where he learned the use of an AED. It occurred to both of us to wonder how those cope with a dextrocardiac patient, especially if the patient is unable to tell rescuers about their condition or is unaware of it themself.
According to this, " When defibrillating a patient with dextrocardia, the pads should be placed in reverse positions. That is, instead of upper right and lower left, pads should be placed upper left and lower right.
If it was me, I would have that clearly stated on my medic alert or watchband so someone would know I was dextrocardiac, but that doesn’t mean they would do the right thing if they noticed it. If I found someone lying on the ground with a medic alert that said dextrocaria, and I had an AED device handy, I would probably ask 911 if they knew what it meant. Hopefully they could guide through the reverse pads position placement.
That makes sense. Now, if the patient either isn’t wearing any sort of medic alert or is not aware they have the condition to begin with…
For those, like me, who didn’t know:
Dextrocardia is a rare congenital condition in which the apex of the heart is located on the right side of the body, rather than the more typical placement towards the left.
-Wikipedia
Whoops, sorry, I probably should have made sure to define terms that aren’t in the normal Doper’s ordinary vocabulary.
The success rate of AEDs in the wild is approximately zero. Doing the correct or incorrect pad placement on any given patient only very slightly alters their chances between correct = nearly zero and incorrect = absolutely zero.
An interesting theoretical concern, but not a practical one.
Overall survival to hospital discharge was 7%. Survival was 9% (382 of 4,403) with bystander cardiopulmonary resuscitation but no AED, 24% (69 of 289) with AED application, and 38% (64 of 170) with AED shock delivered.
This is just not true. Prompt use of an AED (within the first 5 minutes) at least doubles the probability of survival to hospital discharge over CPR alone, and in some studies the improvement is in excess of an order of magnitude. (Discounting the assumed 7% of people who would survive regardless gives 31 out of 100 surviving with prompt application of an AED followed by CPR versus 2 in 100 for CPR alone).
AEDs aren’t magic, and despite how you see defibrillation portrayed in movies and television, the purpose is not to ‘restart’ the heart but rather to stop the spastic fibrillation that prevents the heart muscle from effectively pumping blood so that the body can reestablish the correct rhythm. An AED will automatically detect fibrillation, and will not arm if it detects either no heartbeat or a steady heartbeat signal. Frankly, I don’t know that an AED would even fire on a patient if the pads were reversed, and dextrocardia is a pretty rare condition (less than 1 in 10,000) so it wouldn’t be the first thing even a paramedic would look for if the AED won’t arm. Most untrained rescuers don’t think to look for a medical bracelet or pendant, and they are frequently even missed by paramedics and EMTs, so if you had reversed organs you’re probably not going to be resuscitated.
Stranger
I don’t think pad placement would have any effect on defibrillating the pt, but it might have an effect on identifying a shockable rhythm, something EMS mostly do with their eyes.
I found this study, which probably was done in the hospital, so identifying the rhythm probably isn’t addressed.
A case of dextrocardiac ventricular fibrillation arrest | Emergency Medicine Journal (bmj.com)
Thanks for the corrections @gnoitall & @Stranger_On_A_Train.
It appears I had conflated the low success rate of CPR in the field with that of AEDs in the field. Big difference. And comforting to know.
Yeah, the dirty ‘secret’ about CPR is that despite how much it is promoted by the American Heart Association and American Red Cross, by itself it is rarely effective without defibrillation, and most patients who survive in field-applied CPR would have recovered anyway. AEDs, however, dramatically improve the odds of survival to discharge, and the campaign to have them widely available in public locations and facilities is well-founded.
Although CPR is taught in Wilderness First Response/First Aid classes, in a true backcountry scenario miles away from professional medical care if I came across an unresponsive patient with no heartbeat I probably wouldn’t even start CPR because there is no way to maintain compressions while evacuating the patient and virtually no chance of return of spontaneous circulation if the patient has not been breathing for more than a few minutes.
Stranger
Well, yes and no. Prolonged CPR is known to have saved people struck by lightning in the backcountry.
The thing is, lots of things can cause a person to collapse in a parking lot for which nothing can be done. Those don’t count as failed CPR for the purposes of deciding on recommendations for when to do CPR when you don’t know what’s wrong with the pt.
We throw Narcan at unresponsive people for whom we have no information all the time, it only works on the ones with too much opiates in their system, it’s not some dirty secret that it failed to save all the others.
I’ll also add that effective CPR is harder work that many realize. I’d be interested in a breakdown of survival rates with high quality CPR vs low quality, although I doubt that’s possible.
Permit me to clarify; if I came across an unresponsive patient with the expectation that he or she had not been breathing for several minutes (e.g. unresponsive and showing signs of hypoxia) I would not attempt CPR. If I observed someone struck by lighting or spontaneously falling I’d make the effort even knowing the long odds on successful resuscitation. Lighting strikes are a special case because people who appear completely unresponsive and not breathing often spontaneously recover, and CPR can help extend usable time before permanent brain damage occurs.
Doing effective CPR is incredibly tiring; unlike what you see on television, you really have to push all weight down on the chest, often fracturing ribs. I’m not sure what you mean regarding “high quality” versus “low quality” CPR; any effort that isn’t sufficiently compressing the heart or maintaining a 100-120 compressions/minute rate is not going to be effective, and it is difficult for even a fit person to maintain that for more than 8-10 minutes at a time without switching out with a partner. (Anyone can do CPR with guidance; you do not need to be Red Cross certified, and ‘Good Samaritan’ laws will protect you from liability.) The big open question currently is whether or not rescue breathing actually does any good. For single rescuer situations, it is now typically recommended to forgo stopping to do rescue breathing and just maintain compressions, and even for dual responders it is probably better for one responder to just maintain airway, look for signs of resuscitation, and be prepared to switch out when the primary gets tired of compressions.
Stranger
Definitely!
If I witnessed a lightning strike which causes a pulseless non-breathing event, I’d make sure to do a pre-cordial thump once or twice before initiating CPR. The thump provides about 0.6 joules and may be enough to convert pulseless ventricular tachycardia back to a perfusing rhythm. Or so I was taught in past advanced cardiac life support classes. It probably won’t work, but it’s unlikely to make them more dead.
I assumed this was the same as situs inversus, but apparently it’s a different condition. It’s possible to have situs inversus with either dextrocardia or levocardia, so they’re apparently independent abnormal body layout issues. Situs inversus tends to mean dextrocardia on its own, so having levocardia with situs inversus is much rarer, such that you basically won the lottery in terms of abnormal body layout.
Yeah, the movie version of CPR is that someone uses CPR, and as a result of that, the patient recovers and gets up again. In reality, CPR almost never causes recovery: It just delays death, hopefully long enough for the ambulance to get there and do the things that will actually bring recovery.
A defibrilator, however (either the one in the ambulance or hospital, or an AED) can actually cause recovery (though you probably still want a medical professional ASAP). So it’s no surprise that survival stats are much better with an AED than without.
And as an aside, AEDs are really easy to use. Basically, it amounts to “put the pads on the skin such that the heart is somewhere in between them, and push the button”. Everything else is automated. CPR (which is usually used along with the AED) is much more difficult.
I have seen a lot of people who were successfully resuscitated by both CPR and AEDs. It is not a characteristic sample because not all cases are equally likely to be brought to a hospital. But it is certainly common enough that it makes an enormous difference for many people. AEDs should be in every big building and at every sports venue.
Because a shock is delivered close to the sternum through skin, I would guess a significant number of patients with a right-sided dysrhythmic heart would still benefit from these interventions.
I am no expert, but from what I was taught, this is quite true. It was a long time ago and the impression I got from the instructor was it probably won’t work but the effort was worth it none-the-less.
On a more promising note, our local fire department is equipping their fire trucks with CPR vests-essentially pneumactically powered vests that the fire fighters put on the victim and just start the compressor. The vest does all the work. Around here when there is an emergency medical call the fire trucks roll as well as the ambulances. There are more fire houses than ambulance bases so the trucks often get there first. The sample size is quite small but the chief says their success rate for CPR more than doubled. They are convinced.
My dad (not my biological father, clearly) had Situs Inversus with Dextrocardia. He wore a bracelet warning of his condition, for all the good that would do…
I wouldn’t consider myself an expert, either. But I was an EMT for around 8 years before a back injury forced me to retire from the profession.
Yes, I’m my professional experience, CPR is incredibly tiring. Our general rule was to switch out every two minutes to keep from getting too fatigued, even when we were assisting hospital staff with working a patient.
It’s grueling work. And often with an undesirable outcome. But the times when it works make you feel like the effort is totally justified.