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Just wondering how people on this board are dealing with patients that have Pacemakers and/or AICDs and present for non-cardiac surgery... do you have the device reps come to the pre-op holding area to deal with them, use a magnet, etc.
Every single one of us. Pacer/AICDs are so common it would be unusual if you dont have to deal with it. In an ideal academic setting, you have someone come in to interrogate the pacer (rep/pacer clinic) if there is no recent interrogation. You can check the model with an xray if the patient doesnt know or have the card to see what the default mode is. I personally see no need to routinely use a magnet, but I do have it available.
Our EP dudes disagree with this. They feel if there if VF/VT its easier to just remove the magnet and let the patient get shocked rather than firing up the transcutaneous pads.
I agree with this because it also saves you from coordinating with the EP rep as well. Our EP dudes also assure me it is very unlikely the magnet will affect the current programming of the device.
For some reason I thought I read somewhere that placing a magnet could potentially disable the AICD😕
while the magnet is on it is disabled, do you mean after it is removed it may remain disabled?
At our place we hve the magnet by the Anesthesia Machine. Then...we dont really worry too much about it, but cards typically comes by in the PACUto check up on the pt.
Not all ICDs respond the same way to magnets. Not all ICDs made by the same company respond the same way, that's why it's safest to deactivate the defib part. Our EP guys had a fit a while ago and now the reps do it. For the money they make on the devices, it's a small sacrifice.
Please list ONE AICD where a magnet placed over the device and left there doesn't deactivate it. Every Rep claims that a magnet will deactivate their brand. I know there are some "defective" AICD's out there but they are few and far between plus the patients kmow if their AICD was recalled by the manufacturer.
Anyway, I can't get the reps to show up preop unless it is an extenuating circumstance. I can get them to come post-op.
It can be tricky.
Medtronics pretty reliably respond as pacers do. i.e. magnet shuts off tachy therapy and removal returns it to the previous programming.
St. Judes CAN be programmed to ignore a magnet.
Guidant is a mess. They can be programmed to ignore a magnet and can be programmed to permanently shut off all tachy therapy if the magnet is left on for >30 sec. Also, one of the ways to "fix" all those Guidant ICDs that malfunctioned was to turn OFF the magnet responsiveness. So some Guidants out there will NOT shut off with a magnet, and some will shut off and STAY shut off if the magnet is on there for more than 30 sec.
The most important thing is to have someone (either cardiology or rep) tell you what a magnet will do to that device. That can be done as a preop workup. Then you and the surgeon need to determine from that whether it needs to be shut off for the procedure, be turned back on at the end of it, or just be prepared with a magnet in the room.
Yeah it can be a pain, but if your patient's ICD discharges during retinal surgery or you send a patient out into the world having inadvertently shut off their ICD, you could be a world of hurt.
(Much info gleaned from publications by Marc Rozner, MD, PhD)
It can be tricky.
Medtronics pretty reliably respond as pacers do. i.e. magnet shuts off tachy therapy and removal returns it to the previous programming.
St. Judes CAN be programmed to ignore a magnet.
Guidant is a mess. They can be programmed to ignore a magnet and can be programmed to permanently shut off all tachy therapy if the magnet is left on for >30 sec. Also, one of the ways to "fix" all those Guidant ICDs that malfunctioned was to turn OFF the magnet responsiveness. So some Guidants out there will NOT shut off with a magnet, and some will shut off and STAY shut off if the magnet is on there for more than 30 sec.
I think it's completely f%& ked that a topic this complicated (and critical) is not taught AT ALL in medical school and we, the responsible party, are meant to learn it "on the job."
My St. Jude rep. claims all AICD's in my area ARE magnet sensitive.
Guidant agrees some "older" AICD's can be a problem but those patients are told about potential problems with surgery. The rep. told me to call her with model number/i.d. if I have any doubts.
All reps agree to check AICD's prior to discharge. Thus, no patient goes home without having his/her AICD verified as functioning properly.
Over 200 cases and counting so far with this strategy and no problems.
We will continue to utilize it as it seems to work fine..
I think it's completely f%& ked that a topic this complicated (and critical) is not taught AT ALL in medical school and we, the responsible party, are meant to learn it "on the job."
I think it's completely f%& ked that a topic this complicated (and critical) is not taught AT ALL in medical school and we, the responsible party, are meant to learn it "on the job."
David,Bro, I hear ya. I was on a case the other day, and the PD Attending comes in and puts a magnet over the pacemaker/defibrilator (not even sure which it was and the CA-1 was being pushed hard, so he wasn't even sure.
*******O.k., as I understand it, there are essentially 3 methods of using an implant.
1) bradycardic patients that rely on the pacemaker to maintain normal sinus rythm
2) tachcardic patients that rely on the pacemaker to maintain normal sinus rythm (not sure how this is actually done, frankly)
3) patients with various heart blocks that need monitoring for asystole, in which case the defibrilator/cardioverter kicks in.
*****My other understanding is than monocaudery devices completely mess with the ECG on the monitor (even if placing the ground lead in the proper place), and thus can cause the pacer/defibrilator to either send a pacing signal, OR defibrilate a patient whose heart is doing just fine, in reality.
SO, the magnet disables the pacemaker and the anesthesiologist is then able (to the best of his/her ability) monitor the ECG for pt problems (again, as best as the bove will allow)??
Is this correct logic? Can someone with more experience elaborate on how a pacer corrects tachy??
Sorry for the "dumb" framing of this question/topic, but like my med student colleague suggests, we just don't get this stuff formally, and baby Miller 4th edition is not much help.
Thanks,
cf
David,
For a magnet to work on a pacer or an AICD the magnet function has to be enabled which allows the magnet to control a switch on the device.
Most devices have that function enabled but in some cases it is disabled like in patients who are exposed frequently to magnetic fields due to their work or life style.
Placing a magnet on a pace maker does not disable it, it just disables the sensing function which puts it in an asynchronous mode (pacing continuously).
Placing a magnet on an AICD disables the arrhythmia detection function so the device will not deliver a shock as a response to electrical interference or actual arrhythmia.
I hope this helps.
Please list ONE AICD where a magnet placed over the device and left there doesn't deactivate it. Every Rep claims that a magnet will deactivate their brand. I know there are some "defective" AICD's out there but they are few and far between plus the patients kmow if their AICD was recalled by the manufacturer.
Anyway, I can't get the reps to show up preop unless it is an extenuating circumstance. I can get them to come post-op.
The newer devices seem to be more immune to interference, but the ASA still recommends to interrogate the device before discharge, which I think is reasonable.
I think this is reasonable. However, it is not logistical in my practice. Not in the least. We don't have cardiologists willing to do it regularly during their scheduled days and reps can sometimes be in other cities or counties and not be able to stop by for hours. One could argue that it could be prearranged but then we would have so many arrangements with our elderly vascular folks that it would move up the hospital chain to higher more pre-op folks and nothing would ever get done. We would just be fighting and fighting it.
Does this mean you never use a magnet or call a rep unless something is actually going wrong with the pacemaker? Do you not treat patients with pacers any differently except having a magnet available?
I'm not criticizing your practice. I'm just curious and if this is how you practice, have you never been burned by a problem?
Sometimes I do think we overestimate the risk of a problem due to case reports. But I don't have enough experience yet to stray from the consensus guidelines.
You know what will happen if one of these folks dies because of device malfunction after discharge?I think this is reasonable. However, it is not logistical in my practice. Not in the least. We don't have cardiologists willing to do it regularly during their scheduled days and reps can sometimes be in other cities or counties and not be able to stop by for hours. One could argue that it could be prearranged but then we would have so many arrangements with our elderly vascular folks that it would move up the hospital chain to higher more pre-op folks and nothing would ever get done. We would just be fighting and fighting it.
Does this mean you never use a magnet or call a rep unless something is actually going wrong with the pacemaker? Do you not treat patients with pacers any differently except having a magnet available?
I'm not criticizing your practice. I'm just curious and if this is how you practice, have you never been burned by a problem?
Sometimes I do think we overestimate the risk of a problem due to case reports. But I don't have enough experience yet to stray from the consensus guidelines.
You know what will happen if one of these folks dies because of device malfunction after discharge?
Does this mean you never use a magnet or call a rep unless something is actually going wrong with the pacemaker? Do you not treat patients with pacers any differently except having a magnet available?
I'm not criticizing your practice. I'm just curious and if this is how you practice, have you never been burned by a problem?
Sometimes I do think we overestimate the risk of a problem due to case reports. But I don't have enough experience yet to stray from the consensus guidelines.
Placing a magnet leads to unpredictable behavior in AICDs.Have seen AICD's fire due to cautery a few times already in my career. Most recently, it was during a L humerus ORIF. For urgent/emergent cases where the ICD was not reprogrammed preop, just place a magnet
Would you rather have it shock the pt multiple times during a case? I put the magnet on for ICD's that haven't been reprogrammed b/c it predictably covers my assPlacing a magnet leads to unpredictable behavior in AICDs.
They are predictable only in pacemakers (most of them will convert to asynchronous pacing mode). One cannot predict what an AICD will do.And magnets aren't actually unpredictable in ICD's
In our practice, have seen/heard of AICD's fire due to cautery a few times already in my career. Most recently, it was during a L humerus ORIF. For urgent/emergent cases where the ICD was not reprogrammed preop, just place a magnet
Cardiologist checked the device, was found to have fired multiple times during case, pt was paralyzed during caseInteresting. Curiously, what happened after? For an AICD, I would probably go magnet if it is the proximal humerus. For belly cases, I just let it ride now (the one I called the Medtronic rep on was an open nephrectomy) and haven't had any issues. I see partners that still throw the magnet on for belly cases. I don't think it is necessary.
I understand that. However, it hasn't happened to my knowledge. Not saying I agree with it or that it's the best way to do it. But the proposal to have every device interrogated prior to discharge just isn't logistical in my practice. We see a ton of elderly patients. The PACU would be overflowing. Just won't happen.
As an aside, that's why I asked the question as to who all has seen a device fire or quit pacing during cautery. The reason I let it ride with my patient the other day was because I knew I could quickly convert to magnet mode asynchronous if necessary, but I also wanted to see how susceptible these things were to interference. The cautery was inches away from the pacer and I saw no interference. I may be more apt to let these devices ride without touching them with a magnet.