Phantom Limb Pain

[SleepIsGood]

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So tommorrow I have a patient that is getting b/l Below Knee Amputation. I dont know anything about the patient since they aren't in house yet.

I was trying to do research as to how to prevent Phantom Limb Pain which apparently can occur in up to 70% of pts that get BKAs.

From what I've read, you should start an epidural...but it should be started 18hours before surgery to attenuate the risk of Phantom Limb Pain.

Anyone know of performing femoral and sciatic nerve blocks for prevention? The limiting factor here to perform b/l femoral and sciatic nerve blocks would obviously be LA toxicity.

Although I would probably need IRB approval (too late now). If a case hasnt been reported it would have been interesting to perform a sciatic and fem block on one lower extremity and nothing on the other or with an epidural.

However, I suspect LA toxicity would be a limiting factor yet again.

Any opinions on management?

 

[coprolalia]

Anyone know of performing femoral and sciatic nerve blocks for prevention? The limiting factor here to perform b/l femoral and sciatic nerve blocks would obviously be LA toxicity.

We do these all the time for single BKA's and AKA's. You can run ropivicaine 0.2% in both catheters. Usually you'll need about 10/hr in the sciatic catheter and 10-12/hr in the femoral for starters. Or, you can do a lumbar plexus and sciatic block.

If you're doing both knees, just put an epidural in. There's no advantage to separately blocking both legs, except that you might diminish the Foley time.

Also, give them some neurontin pre-op, and work-in some ketamine during the case. Haven't had anyone complain of phantom limb who's been blocked and gotten these two drugs as part of the balanced anesthetic. (Just my own anecdotal experience, though.)

And, this has been extensively studied. I doubt you could get a landmark paper (or even a solid case report) published on this.

-copro

 

[dfk]

capsacin

 

[mille125]

We do these all the time for single BKA's and AKA's. You can run ropivicaine 0.2% in both catheters. Usually you'll need about 10/hr in the sciatic catheter and 10-12/hr in the femoral for starters. Or, you can do a lumbar plexus and sciatic block.

If you're doing both knees, just put an epidural in. There's no advantage to separately blocking both legs, except that you might diminish the Foley time.

Also, give them some neurontin pre-op, and work-in some ketamine during the case. Haven't had anyone complain of phantom limb who's been blocked and gotten these two drugs as part of the balanced anesthetic. (Just my own anecdotal experience, though.)

And, this has been extensively studied. I doubt you could get a landmark paper (or even a solid case report) published on this.





I dont mean to knock your technique (which does sound very good). However, I must say that most anesthesiologists have no idea if their patient develops phantom limb pain (mostly because you dont follow them longterm). I am in interventional pain management and see many of these patients. I do try to inform the preceding anesthesiologists about these patients. It seems that the ones who develop phantom pain or those that had very serious vascular disease and pain pre-procedure. Preemptive analgesia is a powerful tool and I applaud your efforts. However, I think that it is too little too late in some of these patients (many were having months or years of pain prior to seeing you). If you are not following some of these patients, you should ask your local vascular surgeon or pain management doctor about the occurence of phantom pain in your patients.

 

[Noyac]

I dont mean to knock your technique (which does sound very good). However, I must say that most anesthesiologists have no idea if their patient develops phantom limb pain (mostly because you dont follow them longterm). I am in interventional pain management and see many of these patients. I do try to inform the preceding anesthesiologists about these patients. It seems that the ones who develop phantom pain or those that had very serious vascular disease and pain pre-procedure. Preemptive analgesia is a powerful tool and I applaud your efforts. However, I think that it is too little too late in some of these patients (many were having months or years of pain prior to seeing you). If you are not following some of these patients, you should ask your local vascular surgeon or pain management doctor about the occurence of phantom pain in your patients.

Your absolutely right. We see them too late and for too short a period. We can do everything correctly in our short time together but it has very little to do with phantom limb pain development. It has usually already begun.

dfk, how do you plan to use capsacin?

 

[urge]

Haven't had anyone complain of phantom limb who's been blocked and gotten these two drugs as part of the balanced anesthetic. (Just my own anecdotal experience, though.)

How long are you following your pts?

 

[Noyac]

Anyone using calcitonin? Give it I.V. for the week post op.

In the future, virtual reality goggles. Program that mimics the intact limb and allows the pt to perform tasks with the limb.

 

[urge]

Anyone using calcitonin? Give it I.V. for the week post op.

What's the mechanism for that?

 

[Noyac]

Researchers are not sure why or how it works.

 

[dfk]

Your absolutely right. We see them too late and for too short a period. We can do everything correctly in our short time together but it has very little to do with phantom limb pain development. It has usually already begun.

dfk, how do you plan to use capsacin?

They are conducting clinical trials with capsaicin used with regional anesthesia. As I understand it, capsaicin will suppress substance P levels for 4-6weeks post-operatively after it is instilled into the surgical wound before closure. i'll see if i can find the article i read about using lidocaine and capsaicin together.

here's a brief video showing mechanism/theory:
http://hms.harvard.edu/public/video/nbbf.mov

 

[Noyac]

They are conducting clinical trials with capsaicin used with regional anesthesia. As I understand it, capsaicin will suppress substance P levels for 4-6weeks post-operatively after it is instilled into the surgical wound before closure. i'll see if i can find the article i read about using lidocaine and capsaicin together.

here's a brief video showing mechanism/theory:
http://hms.harvard.edu/public/video/nbbf.mov

People were doing that same type of studies with capsaicin back when I was a resident.

 

[zippy2u]

Phanthom Limb Pain(PLP)??? WTF Pops!! That cat would have been lucky if I even saw him in a post op visit the next day when I was a resident. Dude didn't develop PLP in the PACU then he never got it cause that's the last time I saw the pt. Regards, ----Zippy

 

[coprolalia]

How long are you following your pts?

How long does PLP take to manifest?

We, for some reason, seem to get a LOT of vasculopathic/neuropathic patients coming into our joint for various amputations. I've done cases where the ketamine/block technique wasn't used. Some of those patients began complaining of PLP immediately in the PACU.

Usually I f/u 24 hoursafter wards. Blocks still in place. Haven't seen PLP manifesting in that timeframe. Our pain service follows these patients until the block is pulled. Usually 5 (or so) days, and then the next day after the block is out before they go home or to rehab. FWIW, have not heard of them developing PLP in that timeframe.

If you're telling me that PLP can start weeks later without any inkling that it was going to happen in the immediate post-operative period, then you're right: I don't have a true number or appreciation of the patients that I'm missing who go on to develop it. From my experience, if they're going to get it you see it early and declaratively.

-copro

 

[Planktonmd]

Phanthom Limb Pain(PLP)??? WTF Pops!! That cat would have been lucky if I even saw him in a post op visit the next day when I was a resident. Dude didn't develop PLP in the PACU then he never got it cause that's the last time I saw the pt. Regards, ----Zippy

😀
This reminds of an old surgeon who was upset that I checked liver enzymes on a patient with known hep C before a radical prostatectomy,
He said: "the reason he has elevated enzymes is because you checked them".
He was right.

 

[urge]

How long does PLP take to manifest?

Would a pain guy care to chime in?

 

[Noyac]

How long does PLP take to manifest?

there is no defined timeframe for PLP. It can occur immediately after the insult, weeks later, months and rarely even years after the insult.

 

[lobelsteve]

Mayo Clinic website:

The sensation of pain from an amputated limb is the defining symptom of phantom pain. Characteristics of phantom pain include:

Onset within the first few days of amputation
Tendency to come and go rather than be constant
Seeming to come from the part of the limb farthest from the body, such as the foot of an amputated leg
May be described as shooting, stabbing, boring, squeezing, throbbing or burning
May be triggered by weather changes, pressure on the remaining part of the limb or emotional stress


From a PM&R Board Review Book (Cuccurillo)

3. Phantom pain:
• Awareness of pain in the portion of the extremity that has been amputated. It may accompany
the phantom sensation, localizing in the phantom limb rather than in the residual
limb.
• The pain has been described as cramping, aching, burning, and, occasionally lancinating
• Etiology: phantom pain appears to be related to neuron deafferentation hyperexcitability.
• It may be diffuse throughout the entire limb or may be localized to a single nerve distribution.
• Studies have suggested that 50% to 85% of amputees experience some phantom limb pain.
• Recent data do not suggest a predisposition for phantom limb pain among traumatic
amputees, elderly amputees, or those with pain in the amputated limb before amputation.
There appears to be no correlation between phantom pain and amount of time after amputation
or use of prosthesis.

PROSTHETICS & ORTHOTICS
449
Cuccurullo-06 (407-486) 3/25/03 1:37 PM Page 449

• Phantom pain usually diminishes with time and chronic phantom pain is rare. The occurrence
of phantom pain generally is considered to be a significant long-term problem in
only 5% or less of the total amputee population.
• If pain persists greater than than 6 months, prognosis for spontaneous recovery is poor.
• Phantom pain does not occur in congenital amputation.

 

[Noyac]

Mayo Clinic website:

The sensation of pain from an amputated limb is the defining symptom of phantom pain. Characteristics of phantom pain include:

Onset within the first few days of amputation
Tendency to come and go rather than be constant
Seeming to come from the part of the limb farthest from the body, such as the foot of an amputated leg
May be described as shooting, stabbing, boring, squeezing, throbbing or burning
May be triggered by weather changes, pressure on the remaining part of the limb or emotional stress


From a PM&R Board Review Book (Cuccurillo)

3. Phantom pain:
• Awareness of pain in the portion of the extremity that has been amputated. It may accompany
the phantom sensation, localizing in the phantom limb rather than in the residual
limb.
• The pain has been described as cramping, aching, burning, and, occasionally lancinating
• Etiology: phantom pain appears to be related to neuron deafferentation hyperexcitability.
• It may be diffuse throughout the entire limb or may be localized to a single nerve distribution.
• Studies have suggested that 50% to 85% of amputees experience some phantom limb pain.
• Recent data do not suggest a predisposition for phantom limb pain among traumatic
amputees, elderly amputees, or those with pain in the amputated limb before amputation.
There appears to be no correlation between phantom pain and amount of time after amputation
or use of prosthesis.

PROSTHETICS & ORTHOTICS
449
Cuccurullo-06 (407-486) 3/25/03 1:37 PM Page 449

• Phantom pain usually diminishes with time and chronic phantom pain is rare. The occurrence
of phantom pain generally is considered to be a significant long-term problem in
only 5% or less of the total amputee population.
• If pain persists greater than than 6 months, prognosis for spontaneous recovery is poor.
• Phantom pain does not occur in congenital amputation.

Looks like we are saying the same thing.

 

[mille125]

Would a pain guy care to chime in?

It can develop at any time and I have seen many cases that did not present until after the immediate post op period. This leads me to believe that many anesthesiologists would detect a lot of false negative (and hence feel that their technique prevents most phantom limb pain). Don't get me wrong: ketamine, capsacian, and neuroaxial techniques are all helpful and I would request them if I were a soon to be amputee. However, most of the damage has already been done before the perioperative period. The spinal cord has already been totally bombarded by a barrage of nociceptive input from a severely vasculopathic extremity.

 

[mille125]

capsacin

what is your mode of delivery of capsacin....most patients apply it topically....how are you delivering it at your institution..

 

[dfk]

what is your mode of delivery of capsacin....most patients apply it topically....how are you delivering it at your institution..

they aren't that "advanced" at my institution.
i have read introducing it with lidocaine for injection.
it is my understanding that somehow the capsaicin latches on to the local, crosses the nerve,
then gets up in the channel.
again, i personally have not had hands-on, but would be willing to try it.

 

[urge]

they aren't that "advanced" at my institution.
i have read introducing it with lidocaine for injection.
it is my understanding that somehow the capsaicin latches on to the local, crosses the nerve,
then gets up in the channel.
again, i personally have not had hands-on, but would be willing to try it.

I wonder if you can just squirt some Tabasco into the wound. Next time I get wound I'll try it. I'm afraid it's going to hurt like a mofo.

 

[Planktonmd]

I wonder if you can just squirt some Tabasco into the wound. Next time I get wound I'll try it. I'm afraid it's going to hurt like a mofo.

He doesn't really know.
He just heard that Capsaicin can be helpful in PLP but he has no idea how.
There are many people out there trying to make money from this old drug.
They are trying to attribute some miraculous effects to it which reminds me of the marketing campaign for Trmadol, Neurontin and more recently Lyrica...
We'll see if Capsaicin will do better.

 

[mille125]

Capsaican is only delivered topically in the form of a cream in clinical practice. That is why I was curious to know about dtk's trial. Capsacian has been applied via intravenous, inhalational and topical routes in the lab.


The role of capsacian in central pain states (ie phantom limb pain) is usually beyond the scope of what most anesthesiologist want to know. However, there seems to be a lot of interest in this particular thread. I will give a quick synopsis.


Intense peripheral stimulation (ie nociceptive input from an ischemic limb) releases substance P into the spinal cord. The causes increased central hypersensitivity and increase pain sensitivity. This has also been recently implicated in fibromyalgia. Infusion of substance P into animals reliably causes a cardiovascular response and defensive behaviors typical of a stress response. Substance P is also present in the amygdala and limbic systems tying in an emotional response to pain. Capsaican is thought to be a substance P antagonist. You may hear more about this class of drug in the future. Unfortunately, capsacian has the unpleasant side effect of burning when applied. I feel that it would be hard to do any clinical trial with it and this is why I was interested in the study design in the previously mentioned post.

 

[Noyac]

Capsaican is only delivered topically in the form of a cream in clinical practice. That is why I was curious to know about dtk's trial. Capsacian has been applied via intravenous, inhalational and topical routes in the lab.


The role of capsacian in central pain states (ie phantom limb pain) is usually beyond the scope of what most anesthesiologist want to know. However, there seems to be a lot of interest in this particular thread. I will give a quick synopsis.


Intense peripheral stimulation (ie nociceptive input from an ischemic limb) releases substance P into the spinal cord. The causes increased central hypersensitivity and increase pain sensitivity. This has also been recently implicated in fibromyalgia. Infusion of substance P into animals reliably causes a cardiovascular response and defensive behaviors typical of a stress response. Substance P is also present in the amygdala and limbic systems tying in an emotional response to pain. Capsaican is thought to be a substance P antagonist. You may hear more about this class of drug in the future. Unfortunately, capsacian has the unpleasant side effect of burning when applied. I feel that it would be hard to do any clinical trial with it and this is why I was interested in the study design in the previously mentioned post.

Mille, are you telling me fibromyalgia is REAL?😉

 

[mille125]

Mille, are you telling me fibromyalgia is REAL?😉

i am afraid so.......

 

[lobelsteve]

Mille, are you telling me fibromyalgia is REAL?😉

Yep, but don't worry: Opioids don't work for FMS.

http://forums.studentdoctor.net/showthread.php?t=518718&highlight=fibromyalgia

 

[dfk]

He doesn't really know.
He just heard that Capsaicin can be helpful in PLP but he has no idea how.
There are many people out there trying to make money from this old drug.
They are trying to attribute some miraculous effects to it which reminds me of the marketing campaign for Trmadol, Neurontin and more recently Lyrica...
We'll see if Capsaicin will do better.

this is the latest that i found, which is what i was trying to explain:

"Enter the hot chili pepper, in the form of capsaicin.

Enter, too, a failed derivative of the common anesthetic lidocaine, invented in the 1940s. The derivative, known as QX-314, was deemed useless because it couldn't penetrate cell membranes to block sensation. In non-pharmaceutical terms, that's a bit like having a power shovel that can't cut earth.

In experiments, the Harvard researchers found that the chili pepper ingredient generated heat that opened the gate to pain neurons, but had no similar effect on other nerve cells. Then, when they introduced the lidocaine derivative, it charged through the open channels to block pain in those neurons, but was still unable to enter other nerve cells, such as "motor" neurons that control coordination and mobility.

Thus, in rat experiments, there appeared to be a total shutdown of pain, with no apparent numbness or paralysis.

The rats received injections near nerves leading to their hind feet, and lost the ability to feel pain in their paws. But they continued to scamper about their cages normally and showed sensitivity to touch and other stimulation.

"We introduced a local anesthetic selectively into specific populations of neurons," said Bean. "Now we can block the activity of pain sensing neurons without disrupting other kinds of neurons that control movements or non-painful sensations."

Experimentation will likely move on to to sheep, then humans. One problem that needs to be addressed is whether the capsaicin might cause such a burning sensation when first injected -- before the lidocaine derivitive shuts down the pain -- that it may be too uncomfortable for use as an anesthetic. But the researchers are confident they can find a more practical "warming" chemical to open the gateways to the pain neurons.

"This method could really transform surgical and post-surgical analgesia. Patients could remain alert without suffering pain. But they also wouldn't have to cope with numbness or paralysis," Woolf said.

Noting that itch-sensitive neurons are similar to nerves that sense pain, he added: "We may have even found a good treatment for the common itch."

http://www.nature.com/nature/journal/v449/n7162/full/nature06191.html