80% relief better than 50%?

[GMEN]

This article appeared in the most recent pain physician journal:

http://www.painphysicianjournal.com/2010/march/2010;13;133-143.pdf

Anyone switching to or currently using 80% relief (instead of 50% relief) with a diagnostic block to diagnose facet syndrome and proceed to a second block and possible RFA?

---

Members don't see this ad.

 

[facets]

Yes, BTW BC of AZ requires 75-100 % relief before paying for RF, they hate paying for RF

 

[Pain_doc]

Each insurer has their own criteria. LCDs for medicare in my area require documentation of 80% relief on 2 separate locations. This was a change for medicare. Of course, if I didn't read their LCDs (for something completely unrelated), I wouldn't have known. At least with insurers, you'll get a denial letter with some sort of explanation.

 

[Aether2000]

I am fascinated by this paper since the author argued against the ISIS guidelines (80% relief) in print and in public in the Noridian issue. Because 50% seems too close to the placebo of 35%, perhaps 80% does indeed make more sense, lest we have no standards at all ala spine surgeons doing fusions.

 

[lonelobo]

50% or 80%
My patients all have trouble grasping the percentage concept.
Typically with them it is "much better", " a little better", "no better", or
"worse"

So for people using the 80% criteria, what are you doing when they say they are 75% better?

 

[Aether2000]

Is rounding permitted?

 

[ampaphb]

MM, please give us a synopsis of your logarithmic pain scale discussion

 

[lobelsteve]

Patient follow up MBB form:

How much relief was there one hour post-procedure:
0%. 20%. 80%. 100%.

Circle one of the above.

 

[TX PAIN DOC]

Patient follow up MBB form:

How much relief was there one hour post-procedure:
0%. 20%. 80%. 100%.

Circle one of the above.

That's too many choices for some patients.


If we move from 50% to 80%, what is there to stop insurance companies to ask for 100% prior to RFA?

 

[ampaphb]

Spine J. 2008 May-Jun;8(3):498-504. Epub 2007 Jun 18.
Lumbar zygapophysial (facet) joint radiofrequency denervation success as a function of pain relief during diagnostic medial branch blocks: a multicenter analysis.
Cohen SP, Stojanovic MP, Crooks M, Kim P, Schmidt RK, Shields CH, Croll S, Hurley RW.

Pain Management Division, Department of Anesthesiology & Critical Care Medicine, Johns Hopkins School of Medicine, 550 North Broadway, Suite 301, Baltimore, MD 21029, USA. [email protected]
Comment in:


Abstract
BACKGROUND CONTEXT: The publication of several recent studies showing minimal benefit for radiofrequency (RF) lumbar zygapophysial (l-z) joint denervation have led many investigators to reevaluate selection criteria. One controversial explanation for these findings is that the most commonly used cutoff value for selecting patients for l-z (facet) joint RF denervation, greater than 50% pain relief after diagnostic blocks, is too low and hence responsible for the high failure rate. PURPOSE: To compare l-z joint RF denervation success rates between the conventional greater than or equal to 50% pain relief threshold and the more stringently proposed greater than or equal to 80% cutoff for diagnostic medial branch blocks (MBB). STUDY DESIGN/SETTING: Multicenter, retrospective clinical data analysis. PATIENT SAMPLE: Two hundred and sixty-two patients with chronic low back pain who underwent l-z RF denervation at three pain clinics. OUTCOME MEASURES: Outcome measures were greater than 50% pain relief based on visual analog scale or numerical pain rating score after RF denervation persisting at least 6 months postprocedure, and global perceived effect (GPE), which considered pain relief, satisfaction and functional improvement. METHODS: Data were garnered at three centers on 262 patients who underwent l-z RF denervation after obtaining greater than or equal to 50% pain relief after diagnostic MBB. Subjects were separated into those who received partial (greater than or equal to 50% but less than 80%) and near-complete (greater than or equal to 80%) pain relief from the MBB. Outcomes between groups were compared with multivariate analysis after controlling for 14 demographic and clinical variables. RESULTS: One hundred and forty-five patients obtained greater than or equal to 50% but less than 80% pain relief after diagnostic MBB, and 117 patients obtained greater than or equal to 80% relief. In the greater than or equal to 50% group, success rates were 52% and 67% based on pain relief and GPE, respectively. Among patients who experienced greater than 80% relief from diagnostic blocks, 56% obtained greater than or equal to 50% relief from RF denervation and 66% had a positive GPE. CONCLUSIONS: Using more stringent pain relief criteria when selecting patients for l-z joint RF denervation is unlikely to improve success rates, and may lead to misdiagnosis and withholding a potentially valuable treatment from good candidates.

Note, Lax's study was "An observational report of an outcome study to establish the diagnostic accuracy of controlled lumbar facet joint nerve blocks."

A previous study of 152 patients showed an 89.5% of sustained diagnosis of lumbar facet joint pain at the end of a 2-year follow-up period when the diagnosis was made with double blocks and at least 80% relief. The present evaluation includes a comparison of the above results with a study of 110 patients undergoing lumbar facet joint nerve blocks with positive criteria of at least 50% relief and follow-up of 2 years."


I may not be an expert in such things, but I was always taught you can't combine the results of two studies and come to any meaningful conclusion.

I trust Dr. Cohen for his science, and Lax to get us paid.

 

[lonelobo]

Is rounding permitted?

Then where does it stop?

 

[SSdoc33]

me: did the injection help
patient: yes
me: how much?
pt: oh, a good deal
me: what percentage would you say, 50%, 75%, 100%?
pt: hmm. well, i dont know about that, but i can stand and do the dishes now.

how the @$@#$ am i supposed to correlate that to a percentage? i just burn if they feel better and can do more things.

 

[knoxdoc]

Most patients can't comprehend percentages. I am going to rephrase my question so as to satisfy insurance companies:

Please pick the best answer:

1) All my pain was gone (100% relief)
2) None of my pain was gone (0% relief)

 

[facets]

Roflmao!!

 

[lobelsteve]

Phone message today:


PATIENT REQUESTS: CALLING BACK TO LET SML KNOW THAT THE PROCEDURE SHE HAD LAST FRIDAY WORKED---PT. STATES IT HAS WORKED ABOUT 80% RELIEF....NEXT STEP??? JM LPN

 

[Mister Mxyzptlk]

There was a very long discussion of this a few months back. The main problem is to define the mission. IMHO, there should be 100% relief of the structure that was blocked. Others disagree.

I think this is a major flaw in a lot of the pain literature. If I have facet and SI pain and you do MBBs I will only have partial relief. If you do RF to relieve my facet pain I will only get partial relief. Then by any measure (pills used, pain scales, etc) my RF procedure will be a "failure".

However, if you do facet RF and prior to the procedure I have facet tenderness but afterward I don't then it was a 100% success, even if I still have pain over my PSIS, even if I still need pills, and even if my pain scale doesn't go to 0.

That is why I think the Cohen study is flawed.

I am so stunned to have amp REQUEST that I say something that I will address the issue of % pain.

Some questions first:

Is VAS = 6 twice as painful as VAS = 3, and 3 times as painful as VAS = 2?
Is the interval from 1 to 2 the same as the interval from 8 to 9?
Do 2 broken legs hurt twice as much as one broken leg?
Is there a zero offset, e.g. heat threshold?

Answers: Nobody knows.

I suspect there is a zero offset. A light massage might feel great, but a deep tissue massage can be unpleasant. There is a heat pain threshold as we know from doing RF (as well as from the literature).

There is also some experimental evidence that pain perception is logarithmic (Price, 1994). This should not be surprising since both sound and light intensity are perceived logarithmically. This allows for huge bandwidth. From an evolutionary standpoint if you're building or adding to a sensory system and modifying the parts already available, and you already have a sensory subsystem that responds logarithmically, most likely all of your sensory organs will function logarithmically.

Going from a 1 to a 2 on the pain scale means what? What percentage is that? Going from 1 -> 2 is 100%, but going from exponent of 1 to exponent of 2 = 1,000% (base 10 system ). Going from 4 -> 5 is 20% using simple arithmetic, but it's 10-fold using logs.

It also seems that it's harder to move a patient from a 2 to a 0 than from 7 to 5. That's the same 2 point drop. Perhaps the stimulus-response curve is not straight. Maybe it's sigmoid. Maybe it's sigmoid with a zero offset and logarithmic. If you're doing a study and use a 2-point drop in pain as your threshold you could run into problems at the extreme ends of the pain scale.

One more point about powers of 10. There 10 kinds of people in this world - those who understand binary math and those who don't.

 

[lobelsteve]

There was a very long discussion of this a few months back. The main problem is to define the mission. IMHO, there should be 100% relief of the structure that was blocked. Others disagree.

I think this is a major flaw in a lot of the pain literature. If I have facet and SI pain and you do MBBs I will only have partial relief. If you do RF to relieve my facet pain I will only get partial relief. Then by any measure (pills used, pain scales, etc) my RF procedure will be a "failure".

However, if you do facet RF and prior to the procedure I have facet tenderness but afterward I don't then it was a 100% success, even if I still have pain over my PSIS, even if I still need pills, and even if my pain scale doesn't go to 0.

That is why I think the Cohen study is flawed.

I am so stunned to have amp REQUEST that I say something that I will address the issue of % pain.

Some questions first:

Is VAS = 6 twice as painful as VAS = 3, and 3 times as painful as VAS = 2?
Is the interval from 1 to 2 the same as the interval from 8 to 9?
Do 2 broken legs hurt twice as much as one broken leg?
Is there a zero offset, e.g. heat threshold?

Answers: Nobody knows.

I suspect there is a zero offset. A light massage might feel great, but a deep tissue massage can be unpleasant. There is a heat pain threshold as we know from doing RF (as well as from the literature).

There is also some experimental evidence that pain perception is logarithmic (Price, 1994). This should not be surprising since both sound and light intensity are perceived logarithmically. This allows for huge bandwidth. From an evolutionary standpoint if you're building or adding to a sensory system and modifying the parts already available, and you already have a sensory subsystem that responds logarithmically, most likely all of your sensory organs will function logarithmically.

Going from a 1 to a 2 on the pain scale means what? What percentage is that? Going from 1 -> 2 is 100%, but going from exponent of 1 to exponent of 2 = 1,000% (base 10 system ). Going from 4 -> 5 is 20% using simple arithmetic, but it's 10-fold using logs.

It also seems that it's harder to move a patient from a 2 to a 0 than from 7 to 5. That's the same 2 point drop. Perhaps the stimulus-response curve is not straight. Maybe it's sigmoid. Maybe it's sigmoid with a zero offset and logarithmic. If you're doing a study and use a 2-point drop in pain as your threshold you could run into problems at the extreme ends of the pain scale.

One more point about powers of 10. There 10 kinds of people in this world - those who understand binary math and those who don't.

We do need to get away from describing pain as a number. It is a useless tool that is well entrenched. Animal models are so much more descriptive. Chest pain like an elephant is sitting on it, neuropathy as a beard of bees or fire ants biting, stabbing like a snakebite, aching like I was thrown around by gorillas.

Maybe colors: yellow like the sun, red like fire, blue like ice, green like (green doesn't hurt).

Of course some colors have true meaning.

 

[Mister Mxyzptlk]

The pain scale I use routinely goes by function, with different levels getting a letter, not a number. It doesn't work for every situation (the quads with baclofen pumps have great pain scales) but it's better than just arbitrary numbers.

 

[Aether2000]

My patients struggle severely with percentages. It is my distinct impression they were asleep during that year of math, so we may have to offer them visual aids. The VAS could easily be correlated to photos of road kill in various angulations of limbs and with the amount of blood produced (sort of like a pain Rorschack test). Another way would be to have a wooden disc cut into 4 equal pieces. Tell the patient to take away the number of pieces corresponding to their pain relief after the injection.
For the seriously mathematically challenged, have the patient paw the table once for no relief, twice for excellent relief....

 

[Jcm800]

me: did the injection help
patient: yes
me: how much?
pt: oh, a good deal
me: what percentage would you say, 50%, 75%, 100%?
pt: hmm. well, i dont know about that, but i can stand and do the dishes now.

how the @$@#$ am i supposed to correlate that to a percentage? i just burn if they feel better and can do more things.

ditto. but i also base it on time. if its 0.5% marcaine and it lasts only 1 hour, what does that mean yo you guys? to me, it should be much longer, i say no go. Am i wrong?

 

[Aether2000]

I have recently started using videofluoroscopy on MBB lumbar for educational purposes, and I am amazed at what I am seeing. Perfectly placed needles injecting the MB, but only posterior to the MAL or tracking along the periosteum to reach the supraspinous ligament without anterior filling along the base of the SAP. Perhaps the medication is not reaching the desired target and is missing part of the nerve fibers that enter the joint over the superiolateral border of the SAP...?

 

[PMR 4 MSK]

I have recently started using videofluoroscopy on MBB lumbar for educational purposes, and I am amazed at what I am seeing. Perfectly placed needles injecting the MB, but only posterior to the MAL or tracking along the periosteum to reach the supraspinous ligament without anterior filling along the base of the SAP. Perhaps the medication is not reaching the desired target and is missing part of the nerve fibers that enter the joint over the superiolateral border of the SAP...?

But if you use 10 cc 1% lido like the guys in my area, you guarantee yourself you'll be doing RFA on the patient next week...

And make sure you add in 40 - 80 mg depomedrol per nerve.

 

[clubdeac]

There was a very long discussion of this a few months back. The main problem is to define the mission. IMHO, there should be 100% relief of the structure that was blocked. Others disagree.

I think this is a major flaw in a lot of the pain literature. If I have facet and SI pain and you do MBBs I will only have partial relief. If you do RF to relieve my facet pain I will only get partial relief. Then by any measure (pills used, pain scales, etc) my RF procedure will be a "failure".

However, if you do facet RF and prior to the procedure I have facet tenderness but afterward I don't then it was a 100% success, even if I still have pain over my PSIS, even if I still need pills, and even if my pain scale doesn't go to 0.

That is why I think the Cohen study is flawed.

I am so stunned to have amp REQUEST that I say something that I will address the issue of % pain.

Some questions first:

Is VAS = 6 twice as painful as VAS = 3, and 3 times as painful as VAS = 2?
Is the interval from 1 to 2 the same as the interval from 8 to 9?
Do 2 broken legs hurt twice as much as one broken leg?
Is there a zero offset, e.g. heat threshold?

Answers: Nobody knows.

I suspect there is a zero offset. A light massage might feel great, but a deep tissue massage can be unpleasant. There is a heat pain threshold as we know from doing RF (as well as from the literature).

There is also some experimental evidence that pain perception is logarithmic (Price, 1994). This should not be surprising since both sound and light intensity are perceived logarithmically. This allows for huge bandwidth. From an evolutionary standpoint if you're building or adding to a sensory system and modifying the parts already available, and you already have a sensory subsystem that responds logarithmically, most likely all of your sensory organs will function logarithmically.

Going from a 1 to a 2 on the pain scale means what? What percentage is that? Going from 1 -> 2 is 100%, but going from exponent of 1 to exponent of 2 = 1,000% (base 10 system ). Going from 4 -> 5 is 20% using simple arithmetic, but it's 10-fold using logs.

It also seems that it's harder to move a patient from a 2 to a 0 than from 7 to 5. That's the same 2 point drop. Perhaps the stimulus-response curve is not straight. Maybe it's sigmoid. Maybe it's sigmoid with a zero offset and logarithmic. If you're doing a study and use a 2-point drop in pain as your threshold you could run into problems at the extreme ends of the pain scale.

One more point about powers of 10. There 10 kinds of people in this world - those who understand binary math and those who don't.

Damn I love reading this @%$#. It's like getting another degree without the debt. Thanks MM

 

[Mister Mxyzptlk]

In secret, when the patient and I are sequestered away where the prying eyes of insurance adjusters dare not tread (can I mix a metaphor or what ), sitting under The Cone of Silence, I ask one simple question after doing MBBs:

"If you could feel like this all the time would it be worth having the procedure?"

 

[SleepIsGood]

This month's article also points out that not only should 80% be the cut off..but also patients MUST BE ABLE TO DO ACTIVITIES tht were painful before.

Also Benyamin points out what Cohen did...use less volume in your facet injections so they're more specific.

 

[Mister Mxyzptlk]

You would think that a patient requesting painful procedures that cost them money would be enough to convince an insurance adjuster that the patient perceived a significant beneficial effect. They can't all be Munchausen's and Worker's Comp malingerers.

 

[DigableCat]

I had a patient a few months ago who received MBBs(not by me).

Put numbers consistent with it being non-diagnostic.

Called me because she wanted to know "What's the next step?"

My next step: Let's get back to PT, lose some weight, try some adjuvant meds..ie...conservative management.

She didn't really like that option.

Nursing called her to discuss. Apparently, she was afraid to say she got relief because she thought that her vicodin would be cut off(she's getting it from her PCP...not me). She really did get relief! Really?

So now she knows how to play the game. The MBBs were repeated. Got the required 50% relief, twice. Moved on to RFA.

She calls me just recently. "No pain relief from RFA...what's the next step?"

Next step....recommend to PCP to taper opiates, get back to PT, lose weight.

I've been underf******whelmed with RFA recently.

 

[Mister Mxyzptlk]

Digable, RFA is fine. The problem is at the other end of the needle with this patient. You can solve your problem by telling her that there is no way you'd ever prescribe pain meds for her condition.