grounding pad placement for RF

[ctts]

I am a bit confused about optimal grounding pad placement. Typically I have been placing on calf. Seems consistent with this SIS document:

https://cdn.ymaws.com/www.spineintervention.org/resource/resmgr/factfinder/FactFinder_2018_10_ExternalB.pdf

"The distance between the dispersive pad and RF electrode is inversely related to temperature; therefore increasing the distance between the dispersive pad and the RF electrode results in decreased temperatures at the dispersive pad surface. As an example, for a left lumbar medial branch nerve RF neurotomy procedure, the dispersive pad might be placed on the right calf in order to maximize its distance from the RF electrode. Finally, placing the dispersive pad with the longest side facing the RF electrode decreases the temperature along the leading edge of the dispersive pad reducing the risk of a burn."


But then another SIS document advises differently:

https://cdn.ymaws.com/www.spineintervention.org/resource/resmgr/patient_safety/safety_practices/sis.safety.practices.m2.3.mb.pdf

A dispersive pad should be completely adhered to the skin with the long axis of the pad facing the active RF electrode to minimize risk of a dispersive pad skin burn. The pad should be placed on the ipsilateral thigh if possible.

Does it matter? What do you think?

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[lobelsteve]

I have always placed the grounding pad adjacent to my working zone, but definitely not where prep is placed or can leak under.
Unsure how the pad can heat up if placed with good skin contact.

I sent your links above to the folks at SIS to get this clarified. The authors of those fact finders will be aware and someone or both will edit.
Thanks for noticing the in-congruency.

 

[willabeast]

I am a bit confused about optimal grounding pad placement. Typically I have been placing on calf. Seems consistent with this SIS document:

https://cdn.ymaws.com/www.spineintervention.org/resource/resmgr/factfinder/FactFinder_2018_10_ExternalB.pdf

"The distance between the dispersive pad and RF electrode is inversely related to temperature; therefore increasing the distance between the dispersive pad and the RF electrode results in decreased temperatures at the dispersive pad surface. As an example, for a left lumbar medial branch nerve RF neurotomy procedure, the dispersive pad might be placed on the right calf in order to maximize its distance from the RF electrode. Finally, placing the dispersive pad with the longest side facing the RF electrode decreases the temperature along the leading edge of the dispersive pad reducing the risk of a burn."


But then another SIS document advises differently:

https://cdn.ymaws.com/www.spineintervention.org/resource/resmgr/patient_safety/safety_practices/sis.safety.practices.m2.3.mb.pdf

A dispersive pad should be completely adhered to the skin with the long axis of the pad facing the active RF electrode to minimize risk of a dispersive pad skin burn. The pad should be placed on the ipsilateral thigh if possible.

Does it matter? What do you think?

i have seen a GPad transmit enough ?electricity? that the patient feels something under the GP. Cannot remember (long time ago) but it got me confused doing a lumbar RF.

 

[RoloTomassi]

i have seen a GPad transmit enough ?electricity? that the patient feels something under the GP. Cannot remember (long time ago) but it got me confused doing a lumbar RF.

Interesting. Had that a couple times too. Not sure how to explain. Placement and motor stim checked out so proceeded.

 

[specepic]

Rep rec's placing CLOSE and perpend to midline. I place on left lumbar if treating right lumbar. Ramp up times will be shorter as well

 

[callmeanesthesia]

I only worry about it if they’ve got metal close to the surface in a limb or an implanted electric device.

 

[lobelsteve]

Thanks to forum member @ctts for getting SIS to change factfinders for consistency.

Thanks Steve.
I have brought this to PSC leadership and they agree that this needs to be addressed.

We will be revising the Safety Practice document.

On page 3 under NEUROTOMY:

A dispersive pad should be completely adhered to the skin with the long axis of the pad facing the active RF electrode to minimize risk of a dispersive pad skin burn. The pad should be placed on the ipsilateral thigh if possible.

The highlighted sentence will be replaced with:
The pad should be placed to maximize its distance from the RF electrode.

Thanks again for bringing this to our attention!!!
B

 

[Ligament]

This is interesting. Placing the grounding pad as far away as possible means the calf in most cases. Long bones absorb a lot of energy. I've had RF generators fail when placing the pad far away, and was in fact advised by a neurotherm engineer that the femur in particular acts as an energy sink due to the marrow cavity. He advised upper thigh or between scapulae. This may be all anecdotal, but who here does place the grounding pad on the calf routinely?

In my area, with two ISIS past presidents, the location was between the shoulder blades or the upper thigh.

I'm open to learning.

 

[DOctorJay]

We got the new Abbott machines. They ask us to place the pads on the upper buttock for lumbar and on the arm for cervical.

 

[oneforfighting]

So is there an explanation for the discrepancy between why the device manufacturers recommend proximal placement of the grounding pads and SIS recommends distal placement? I checked - both Avanos and BS also recommend placement GPs in close proximity to the electrodes.

 

[deleted131481]

So is there an explanation for the discrepancy between why the device manufacturers recommend proximal placement of the grounding pads and SIS recommends distal placement? I checked - both Avanos and BS also recommend placement GPs in close proximity to the electrodes.

I'm not sure but I'll speculate:

SIS - most distal to decrease temperature/risk of burn considering we are leaving it for 90s - 2 min
manufacturers - most proximal to decrease potential risk of interference (e.g. cardiac devices). Maybe a holdover from Bovie pad placement recs.

 

[callmeanesthesia]

Did a C3-5 RF yesterday for a man with a pacemaker. Implanted for severe bradycardia. Requested cardiology clearance - they just said he’s cleared but it may interfere.
Pacer left chest, so I put the grounding pad on the right lateral scapula. As soon as the RF starts, his pacer stops and heart rate plummets to 40s. Also tried with just one needle, still no good. So I ended up doing bipolar ablations C3 to C4, then C4 to C5. That worked fine with no interference. Thought on this alternative?

 

[lobelsteve]

Did a C3-5 RF yesterday for a man with a pacemaker. Implanted for severe bradycardia. Requested cardiology clearance - they just said he’s cleared but it may interfere.
Pacer left chest, so I put the grounding pad on the right lateral scapula. As soon as the RF starts, his pacer stops and heart rate plummets to 40s. Also tried with just one needle, still no good. So I ended up doing bipolar ablations C3 to C4, then C4 to C5. That worked fine with no interference. Thought on this alternative?

Would have placed immediately adjacent to the sterile field.

 

[ziggyziggy]

Did a C3-5 RF yesterday for a man with a pacemaker. Implanted for severe bradycardia. Requested cardiology clearance - they just said he’s cleared but it may interfere.
Pacer left chest, so I put the grounding pad on the right lateral scapula. As soon as the RF starts, his pacer stops and heart rate plummets to 40s. Also tried with just one needle, still no good. So I ended up doing bipolar ablations C3 to C4, then C4 to C5. That worked fine with no interference. Thought on this alternative?

Make sure to check manual and that it's not because of RF interference. I have also seen patient getting shocked during Cervical and moving the pad proximally and laterally solved the problem. Bipolar ablation is a great idea too.

 

[Ducttape]

Place adjacent to field and use magnet to turn off the sensing on the pacemaker and put it in default.
Do not put magnet on AICD. Only on pacemaker. Have rep turn off AICD.