RFA needle sizing for local anesthesia (without sedation)?

This forum made possible through the generous support of SDN members, donors, and sponsors. Thank you.
C

CarabinerSD

Full Member
5+ Year Member
Joined
Oct 23, 2019
Messages
113
Reaction score
24
At my current setup, we only offer local anesthesia (no sedation) for procedures. RFA cannula sizing is 20g (lumbar) and 22g (cervical), MDT Accurian (no cooled RF setup). Needles are placed parallel to medial branch nerve with 90 seconds initial burn followed by a 180 degrees rotation for a 2nd burn. Patients do well with local and don't need sedation. Results are pretty good but I'm always wondering if I could optimize the outcome more by upsizing the needle gauge.

  • For those who don't do sedations, can patients reasonably tolerate 18g lumbar & 20g cervical RFA with just local?
  • My Cervical RFAs are done with 5mm active tip, would 10mm active tip be more optimal here?
  • Genicular is pretty painful, so thinking of sticking with just 20g cannula?
  • I'm adding steroid flush for upper cervical RFAs after burning due to possible neuritis. I know some people don't...thoughts on steroid flush after RFA?
Members don't see this ad.
 
Last edited:
I don't think tolerability is a function of size. I do 18 ga 10 mm Sidekick cervical and lumbar, 90s, 1 burn, do not routinely sedate. The ones who need sedation need it for even the MBBs, cry and squirm during the numbing. Just cannot tolerate any procedure. I numb each track with 3 mL lido 1%, each burn with 1.5 mL lido 2%. That 2% makes a big difference.
 
Members don't see this ad :)
17 cooled, local only usually, sometimes 5 of valium
 
BobBarker said:
I use 10mm 20g for cervicals. One burn. Why not give an oral benzo? It helps a great deal.
Click to expand...

I do give benzo for the really skittish folks...but most of the time don't since they'll need a driver which complicates scheduling for patients. But yea I can give benzo.

But yes I'm hoping to go up a size for needles to do one burn instead of 2 as I'm doing now.
 
RoloTomassi said:
I don't think tolerability is a function of size. I do 18 ga 10 mm Sidekick cervical and lumbar, 90s, 1 burn, do not routinely sedate. The ones who need sedation need it for even the MBBs, cry and squirm during the numbing. Just cannot tolerate any procedure. I numb each track with 3 mL lido 1%, each burn with 1.5 mL lido 2%. That 2% makes a big difference.
Click to expand...

OK that's pretty encouraging so I'm going to go ahead and try 18g lumbar & 20g cervical (all 10 mm active tips) since we need to re-order supplies anyways.
 
25g 3.5-5” track needle skin to bone plus wheel. By the time I place the last one, first is numb. Stick w 18g all c/l spine. 2% lido. Motor test. Burn. Nearly always well tolerated. Po benzo depending on how was during mbb.
 
I do 16g for lumbar always with or without sedation. 18g for cervical but patients usually get sedation
 
I use only local for all RFA, with or without Norco/Ativan preprocedure. No sedation.

18 gauge for cervical, 16 or 18 for lumbar depending on the patient. For patients who didn’t flinch at all with MBB, 16 is usually well tolerated. Everyone else does fine with 18, unless they are the type of patient who had trouble MBB as @RoloTomassi mentioned.

Agree with generous local and 2% before lesioning. I always tell the patient to let me know if they start to experience more discomfort as the needle approaches the target so I can give additional local if needed.

I do inject steroids after cervical RFA, but I still see neuritis not uncommonly, so not sure if it helps.

I also use 16 or 18 for genicular. Generous local down to periosteum, from both AP and lateral approach, is key.
 
Members don't see this ad :)
Me:

20g 10mm cervical, 18g 10mm lumbar

Lido 1% skin

Lido 2%, bupi 0.5% or mixture for lesion

Valium 4, 5 or 10mg 45 min prior

Depo in lumbar, dex in the neck. I have a significant amount of post RFA neuritis in the neck. I don't think dex helps it TBH, but I still do it. I've mentioned my neuritis rates in the neck on this forum, and I've posted pics.

Bilateral cervical MBB for me, really don't like bilateral cervical RFA. I've seen drop head from a cervical RFA. On call as a fellow and saw a disturbing scene where a woman had no ability to keep her upright. Collar dependent. Like something out of a movie. I can't explain it, but she'd just had an RFA. Cervical RFAs take longer, and it's a lot of local in the neck. I do them 2w apart.
 
Had a younger lady today with a neuritis that wasn’t too troublesome but did have some mild drop head type sensation. Nothing that an observer could perceive but she could sense it occasionally. I just told her it was because I did a great job and she will get better before the pain comes back.
 
Can anyone explain why head drop doesn't occur if you do 2 weeks apart?

Or why b/l TON doesn't cause balance issues if 2 weeks apart?

Seems like the idea is the non-denervated side compensates for the ablated one, but why then after the second side is done are there no issues?

I split TON but can't explain it.
 
It just avoids dousing TON in 2% lidocaine bilaterally simultaneously. The RF is a less complete lesion than the 2 hours or so when the lidocaine is active.
 
MitchLevi said:
I split cervical RFA 2w apart because weakness would be present by then, and I'd just not do the contralateral side.
Click to expand...
I split cervical because it’s too much pita/work for me plus volume of local. I still find this more technically demanding to do well than most other procedures.
 
BobBarker said:
It just avoids dousing TON in 2% lidocaine bilaterally simultaneously. The RF is a less complete lesion than the 2 hours or so when the lidocaine is active.
Click to expand...
Thanks that makes sense for short term balance but I thought that the concern was a long term balance issue
 
I give everyone tons of local. Up to and at times exceeding toxic doses according to the anesthesia literature (5mg/kg lido)

And I give it plenty of time to set up

And I use 4% at the lesion site

Still

About half of my patients still complain of a lot of pain throughout the procedure and are at times crying, etc.

I don’t know. Maybe I’m just in an area with sub optimal patients.
 
I mix bupi and lido which seems to help more although some literature says otherwise. Older patients usually do better probably because of less sensitive nerve endings overall. It’s the young ones that feel everything.
 
Timeoutofmind said:
I give everyone tons of local. Up to and at times exceeding toxic doses according to the anesthesia literature (5mg/kg lido)

And I give it plenty of time to set up

And I use 4% at the lesion site

Still

About half of my patients still complain of a lot of pain throughout the procedure and are at times crying, etc.

I don’t know. Maybe I’m just in an area with sub optimal patients.
Click to expand...
Benzo on board? Perhaps give more?
 
Timeoutofmind said:
Yeah.
I usually give around 2 mg of versed.

I used to give more, like four to eight depending…

But I found a lot of these difficult patients just get disinhibited at the higher doses and move all around and the procedure takes forever and sucks.
Click to expand...
Got it.

I’d wager the that bs behavior during rfa inversely correlates to success of rfa….
 
BobBarker said:
They really can’t feel the burning much at all with 1 minute wait and 2%. So more of a patient issue
Click to expand...

I agree. Some patients will flinch and scream no matter what. All the lidocaine in the world won’t fix that. If you use IV sedation and are over zealous in snowing patients into La La land, be prepared to have one eye on the procedure field and another on the pulse ox and airway; you will be flipping patients to ventilate them. As an anesthesiologist, I consciously fight the urge to supervise deep sedation while performing a procedure. If you can’t tolerate the procedure with local and a touch of anxiolytic, find someplace else to go. This isn’t kindergarten.
 
Timeoutofmind said:
I give everyone tons of local. Up to and at times exceeding toxic doses according to the anesthesia literature (5mg/kg lido)

And I give it plenty of time to set up

And I use 4% at the lesion site

Still

About half of my patients still complain of a lot of pain throughout the procedure and are at times crying, etc.

I don’t know. Maybe I’m just in an area with sub optimal patients.
Click to expand...
4% lido probably increases the size of your lesion and denatures the nerve. It also prob hurts a lot more to inject.

Not sure what 4% costs but it's prob expensive.
 
I refuse to do cervical RFA bilateral. I’ve also seen a flail neck. And a patient with long term balance issues. Each of them could have been greatly minimized if the doctor just stopped after the first unilateral RFA.

I will do bilateral thoracic and lumbar RFA.
 
CarabinerSD said:
At my current setup, we only offer local anesthesia (no sedation) for procedures. RFA cannula sizing is 20g (lumbar) and 22g (cervical), MDT Accurian (no cooled RF setup). Needles are placed parallel to medial branch nerve with 90 seconds initial burn followed by a 180 degrees rotation for a 2nd burn. Patients do well with local and don't need sedation. Results are pretty good but I'm always wondering if I could optimize the outcome more by upsizing the needle gauge.

  • For those who don't do sedations, can patients reasonably tolerate 18g lumbar & 20g cervical RFA with just local?
  • My Cervical RFAs are done with 5mm active tip, would 10mm active tip be more optimal here?
  • Genicular is pretty painful, so thinking of sticking with just 20g cannula?
  • I'm adding steroid flush for upper cervical RFAs after burning due to possible neuritis. I know some people don't...thoughts on steroid flush after RFA?
Click to expand...

Timeoutofmind said:
Yeah.
I usually give around 2 mg of versed.

I used to give more, like four to eight depending…

But I found a lot of these difficult patients just get disinhibited at the higher doses and move all around and the procedure takes forever and sucks.
Click to expand...

MitchLevi said:
4% lido probably increases the size of your lesion and denatures the nerve. It also prob hurts a lot more to inject.

Not sure what 4% costs but it's prob expensive.
Click to expand...

I did 99% of RFA in office for 5 years at my first job. I gave Xanax to 100% of the cervical RFA, and 80% of the thoracic/lumbar RVA.

The OP should offer Xanax to 100% of his RFA patients under 60 years old. Xanax definitely helps with in office RFA.

OP, I’d suggest you use 10mm active tip for all spine RFA including cervical.

Agree with 2% lidocaine. Helps a lot and is much less expensive than 4%.

Time out if mind, why do you give IV versed only? If you’re already going to offer an IV med, the usual combo of versed and fentanyl works much better than just versed. And if they struggle with the procedure, then you give them more fentanyl not more versed. Versed is more disinhibiting than fentanyl.

Your average middle aged (not elderly) patient will tolerate RFA much better with 2 versed and 50 mcg fentanyl, than they will with 4 of versed only. And they’ll be more disinhibited with double the versed.

Personally I use 18G needles for all three areas of spine RFA.
16G needles for SIJ and genicular.
 
Last edited:
bedrock said:
I did 99% of RFA in office for 5 years at my first job. I gave Xanax to 100% of the cervical RFA, and 80% of the thoracic/lumbar RVA.

The OP should offer Xanax to 100% of his RFA patients under 60 years old. Xanax definitely helps with in office RFA.

OP, I’d suggest you use 10mm active tip for all spine RFA including cervical.

Agree with 2% lidocaine. Helps a lot and is much less expensive than 4%.

Time out if mind, why do you give IV versed only? If you’re already goong to offer an IV med, the usual combo of versed and fentanyl works much better than just versed. And if they struggle with the procedure, then you give them more fentanyl not more versed. Versed is more disinhibiting than fentanyl.

Your average middle aged (not elderly) patient will tolerate RFA much better with 2 versed and 50 mcg fentanyl, than they will with 4 of versed only. And they’ll be more disinhibited with double the versed.

Personally I use 18G needles for all three areas of spine RFA.
16G needles for SIJ and genicular.
Click to expand...
Thanks man

I still do operating room anesthesia one day a week… and the longer I do it the more paranoid I get!

Which is why I was avoiding the fentanyl and just doing versed. No one gets apneic with just versed.

But your points are well taken and insightful.
 
Thoughts on Valium vs Xanax for in office procedures? I’ve always used valium. Any anecdotes?
 
valium probably deeper effects, but half life is 24+ hours.

xanax might not be as sedating, but its half life is 11 hours.

ativan in my experience is least effective and half life is 12 hours or so.
 
BobBarker said:
2% lido very helpful as mentioned by others for the RF site.

I think cervical mbb/rfa always need a driver. My patients are always very dizzy after.
Click to expand...

More dizzy the higher up the cervical segment right?
 
Is anyone burning at 90 degrees? I came across an old paper that seems to indicate 90 degrees for 3 minutes (painful to wait that long) may make a significant difference in lesion size... Any issues with post-procedural pain when burning at this higher temperature?

academic.oup.com

Factors That Affect Radiofrequency Heat Lesion Size

AbstractObjective. This study aims to compare radiofrequency (RF) heat lesion size across electrodes and generator settings available for interventional pa
academic.oup.com academic.oup.com
 
MD87 said:
Is anyone burning at 90 degrees? I came across an old paper that seems to indicate 90 degrees for 3 minutes (painful to wait that long) may make a significant difference in lesion size... Any issues with post-procedural pain when burning at this higher temperature?

academic.oup.com

Factors That Affect Radiofrequency Heat Lesion Size

AbstractObjective. This study aims to compare radiofrequency (RF) heat lesion size across electrodes and generator settings available for interventional pa
academic.oup.com academic.oup.com
Click to expand...
My partner does 90 degrees for 2.5 minutes. I started off doing that when I started working with him, but felt (anecdotally) like I was getting more failures than I used to so I switched back to 85 degrees 90 seconds x2
 
MD87 said:
Is anyone burning at 90 degrees? I came across an old paper that seems to indicate 90 degrees for 3 minutes (painful to wait that long) may make a significant difference in lesion size... Any issues with post-procedural pain when burning at this higher temperature?

academic.oup.com

Factors That Affect Radiofrequency Heat Lesion Size

AbstractObjective. This study aims to compare radiofrequency (RF) heat lesion size across electrodes and generator settings available for interventional pa
academic.oup.com academic.oup.com
Click to expand...
90 for 90 sec lumbar. 80 degrees in cervical. The lesion would be marginally larger with 2.5 min over 90 seconds, but not meaningfully IMO. No relevant change in post-procedure pain within any of these parameters.
 
90 lumbar, cervical and sacral. 80 genicular.

Seems like I have been doing this way for 5 years without issue. Maybe less

Edit- article shows 20 g at 90 has same lesion size as 18g at 80(the 20 at 90 lesion is actually a bit bigger)I think that was my rationale as I use 20g
 
Last edited:
nvrsumr said:
90 lumbar, cervical and sacral. 80 genicular.

Seems like I have been doing this way for 5 years without issue. Maybe less

Edit- article shows 20 g at 90 has same lesion size as 18g at 80(the 20 at 90 lesion is actually a bit bigger)I think that was my rationale as I use 20g
Click to expand...
Glad that this article was posted. The last time I read it was about 10 years ago, coming out of fellowship, when I had to switch to bipolar technique for sacroiliac, as had cooled rf for that in fellowship. I based my bipolar settings on that.

I have blindly used 80° for 90 seconds for C/T/L since fellowship. All 18 gauge, 10mm, generally 2 burns. Based upon this, I will be making the change to 90°, and considering increase time to 120 seconds. All 18 gauge 10mm, now single burn with this. Any longer on burn time is just so painful (for me)…. As noted when I do 150 seconds on biplolar
 
I’ve been doing 90 degrees for 90s rotate then repeat once fora total of two burns. Typically use 18g for all levels, sometimes in LOLs I’ll use 20g
 
Last edited:
Taus said:
Glad that this article was posted. The last time I read it was about 10 years ago, coming out of fellowship, when I had to switch to bipolar technique for sacroiliac, as had cooled rf for that in fellowship. I based my bipolar settings on that.

I have blindly used 80° for 90 seconds for C/T/L since fellowship. All 18 gauge, 10mm, generally 2 burns. Based upon this, I will be making the change to 90°, and considering increase time to 120 seconds. All 18 gauge 10mm, now single burn with this. Any longer on burn time is just so painful (for me)…. As noted when I do 150 seconds on biplolar
Click to expand...

I’ve been using 85 degrees x 90 seconds for all spine and peripheral joint RFA.

I thought the lesion isn’t consistent below 80 degrees or higher than 90 degrees?

This is why I’ve stuck with 85 degrees x 90 seconds. Safe in the middle.
 
Last edited:
I think that’s an excellent article for 2014 but doesn’t MDT have something about their system that is special that causes it to have the same lesion size as Venom?
 
You must log in or register to reply here.

Similar threads

C
Sacral Lateral Branch RFA (SI Joint) needle size?
Replies
17
Views
1K
cowboydoc
cowboydoc
C
Cervical RFA needle - curved or straight active tip?
Replies
27
Views
1K
BobBarker
BobBarker
S
Cervical RFA with Nimbus needle
Replies
5
Views
864
JFS
J
D
Testing for RFA
2
Replies
66
Views
3K
Ferrismonk
Ferrismonk
P
Nimbus RFA Needles
Replies
3
Views
879
Taus
T
Top