CIED question

[gasman7k]

Dear SDN. Question about a case I had few weeks back. Patient with PPM, pace-maker dependent undergoing sternotomy/CABG. Surgeon doesn't think "modern" pacemakers need reprogrammed or magnet so nothing was done preop. There was clear EMI/bradycardia/hypotension initially but this was transient (about 10s). It appeared that the pacemaker flipped into an asynch mode or became less sensitive to EMI and there were no issues for the rest of the case. I have found nothing in the literature to suggest that modern pacemakers are capable of this intraoperatively. My best guest is this was a bipolar lead pacemaker that already was resistant to EMI and after the chest was open (greater impedance from bovie to lead or whatever) this was no longer a problem.

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[deleted875186]

I’m interested to hear what other people say about why there were only problems with skin. I’m with you, clear indication to place a magnet on the patient, or reprogram.

 

[surgndoc]

I was under the impression all patients that are totally pacemaker dependent should be seen by EP preop to have their devices reprogrammed to an asynchronous mode.
Especially since the effect of a magnet may not be consistent across different manufacturers, battery life of device, or age of the device.

 

[BLADEMDA]

The closer the cautery is to the device (monopolar) the more likely it is to cause interference. IMHO, any surgery where a monopolar cautery unit is used in close proximity to a pacemaker that device should be reprogrammed. This is even more true for a AICD device where the patient is pacemaker dependent.

But, I do agree modern pacemakers are very resistant to EMI these days and rarely need reprogramming. Clinically, there is a big difference between Pacemakers and AICDs IMHO. We have discussed this issue many times before on SDN.

 

[deleted697535]

The latest guidelines we have are cas 2012 and Asa 2011 so not very useful for the newest pacemakers.

And also a massive assertion for the surgeon to make.

Tbh I wouldnt agree with him in a cabg.

Predictors of Emi are clear. <15cm, long regular bursts, unipolar device, monopolar cautery, argon cautery


Is it possible that you communicated the initial hypotension to your surgeon, he crapped his pants a little and started being a reasonable human being and used short bursts thereafter?

 

[deleted875186]

The closer the cautery is to the device (monopolar) the more likely it is to cause interference. IMHO, any surgery where a monopolar cautery unit is used in close proximity to a pacemaker that device should be reprogrammed. This is even more true for a AICD device where the patient is pacemaker dependent.

But, I do agree modern pacemakers are very resistant to EMI these days and rarely need reprogramming. Clinically, there is a big difference between Pacemakers and AICDs IMHO. We have discussed this issue many times before on SDN.

So why do you think the patients pacer only sensed EMI on skin and not while doing the IMA and the rest of the surgery?

 

[gasman7k]

Agree with everything you guys say. Guidelines are clear that this should have been reprogrammed before case. My question is how did we get away with it? Again my guess is heavy bovie burden when getting through skin to sternum (where we saw clear oversensing of pacemaker). After sternotomy only short bursts while taking down mammary and controlling bleeders and what not.

I think we can get away with this half-ass pacemaker management for pump cases that aren't redo and epicardial leads will be placed post CPB. However the surgeon's line of thinking that "modern pacemakers don't need reprogrammed" doesn't apply to other surgeries above umbilicus.

Again, totally different ballgame with AICD and these NEED to be reprogrammed.

Do you agree with this line of thinking?

 

[Maverikk]

And this is for all the residents out there: this applies for surgeries above the umbilicus. I talked to a rep who said that anything below the diaphragm is fine, I confirmed this with an EP doc who said it was institution specific but below the diaphragm is safe

 

[vector2]

Importantly, although rare, CIEDs may revert to a back-up programming mode known as “power-on-reset” when exposed to high-energy EMI. Power-on-reset events are generally resolved by reprogramming the CIEDs to patient specific settings. However, it is important to realize that during power-on-reset, pacing is typically set to an inhibited mode (VVI), and tachycardia therapies are enabled.

https://ahajournals.org/doi/full/10.1161/CIRCULATIONAHA.113.005697

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Most newer devices will revert to a back up mode if they sense enough energy. Additionally, even though they should be programmed, I've heard from a couple EPs that newer devices are tremendously well shielded and are probably ok to leave alone even when bovie superficially on the thorax. I think electrocautery on a sternotomy and LIMA takedown is a different story tho...

 

[MoMoGesiologist]

Pacemakers and AICDs with all the different ways they respond to magnets will forever be the bane of my anesthesia career. How there is no international standard between all the device companies, I will never understand. If any doubt, get it interrogated and reprogrammed!

 

[BLADEMDA]

Importantly, although rare, CIEDs may revert to a back-up programming mode known as “power-on-reset” when exposed to high-energy EMI. Power-on-reset events are generally resolved by reprogramming the CIEDs to patient specific settings. However, it is important to realize that during power-on-reset, pacing is typically set to an inhibited mode (VVI), and tachycardia therapies are enabled.

https://ahajournals.org/doi/full/10.1161/CIRCULATIONAHA.113.005697

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Most newer devices will revert to a back up mode if they sense enough energy. Additionally, even though they should be programmed, I've heard from a couple EPs that newer devices are tremendously well shielded and are probably ok to leave alone even when bovie superficially on the thorax. I think electrocautery on a sternotomy and LIMA takedown is a different story tho...

I have seen this actually occur on more than one occasion. If you are doing a case where the bovie will be in close proximity to any type of CIED that device must be checked after the surgery is completed. Simply placing a magnet over the device is insufficient IMHO to guarantee that device is functioning properly post surgery.

Now, the new devices (2015 and newer) are much better in terms of shielding and EMI but using electrocautery within 12 inches of such a device really is too close for comfort. If you can't reprogram the device then use a magnet for the case but get the CEID checked out prior to discharge or immediately thereafter.

The pacemaker reps will all tell you not to worry and simply use a magnet all the time. That is incorrect and not based on any published guidelines.
I am specifically talking about monopolar cautery in close proximity to the CIED.

 

[deleted697535]

And this is for all the residents out there: this applies for surgeries above the umbilicus. I talked to a rep who said that anything below the diaphragm is fine, I confirmed this with an EP doc who said it was institution specific but below the diaphragm is safe

Where are you getting arbitrary cut offs like diaphragm and umbilicus from when the guidelines say 15cm?

Sometimes devices aren't in the left pec. And hand surgery is above the diaphragm but It's ok to use cautery.

15cm is far easier

 

[BLADEMDA]

Where are you getting arbitrary cut offs like diaphragm and umbilicus from when the guidelines say 15cm?

Sometimes devices aren't in the left pec. And hand surgery is above the diaphragm but It's ok to use cautery.

15cm is far easier

And non pacemaker dependent patients are far more likely to tolerate a disturbance to their device. If the patient is having hand surgery and has a new pacemaker in place I would ask the surgeon to use bipolar (most hand surgeons would agree) and avoid the problem completely. I do think a modern pacemaker (not an AICD) would be just fine without any intervention for hand surgery.

 

[BLADEMDA]

For surgery below the umbilicus, the HRS/ASA statement recommends that there is minimal need to reprogram a CIED or place a magnet on the CIED because the risk of oversensing, generator damage, or lead damage is small. Magnets may still be used, but it is vital to understand the different magnet responses for CIEDs.

Managing Cardiovascular Implantable Electronic Devices (CIEDs) During Perioperative Care

Related Articles: February 2024 Keeping Pace: 2023 Update on the Perioperative Management of Cardiovascular Implantable Electronic Devices (CIEDs) October

www.apsf.org

 

[BLADEMDA]

For ICDs, magnet application will prevent both antitachycardic pacing and defibrillation in order to prevent oversensing of EMI, which may result in inappropriate tachycardia therapy. It is important to remember that all modern ICDs are also pacemakers; however, there is a critical difference in function when a magnet is applied to an ICD versus a pacemaker. In general, a magnet applied to an ICD generator will disable tachycardia therapy; however, it will not have any effect on the pacemaker. Therefore, magnet application to an ICD will NOT place the underlying pacemaker in an asynchronous mode (AOO, VOO, or DOO). For patients who are pacemaker dependent and have ICDs who are undergoing surgery where there is potential for significant EMI, it is best to reprogram the CIED to address both the tachycardic and bradycardic therapy.

 

[Maverikk]

Where are you getting arbitrary cut offs like diaphragm and umbilicus from when the guidelines say 15cm?

Sometimes devices aren't in the left pec. And hand surgery is above the diaphragm but It's ok to use cautery.

15cm is far easier

Just curious and not to be contrarian but where are the guidelines. The last two hospitals I've worked that did a lot of cardiac and EP had different guidelines. So no surgery within 6 inches needs to be interrogated/magnet?

 

[fakin' the funk]

What was the plan for post-op prn pacing? Epicardial wires? Or just use the PPM