Ketamine

[RUOkie]

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The members of the pain listserve will have already seen some of this discussion, but I have a question for the interventionalists here.

Are you guys using Ketamine infusions for CRPS? I have used compounded gels with Ketamine/gabapentin/lidocaine/ketoprofen for years with good success (but only as part of a densensitization program) but do not understand the utility of an IV infusion.

I came down kind of hard on the proponents of this on the listserve because of poor data. If people are using it, though, how can we go about arranging for a big enough trial to prove it works?

 

[Ludicolo]

I’m not an “interventionalist”, but I know the Pain docs at our institution are looking into this. I don’t think anyone is doing it as first line treatment (I hope). The rationale for IV (using my small brain mentality) is that the higher the dosage of ketamine, the better the analgesia, with regards to both symptom reduction and duration. So with better bioavailability, seems like IV administration would thus be more effective than topical or oral.

There was a study in the journal Pain from December last year (Schwartzman RJ, et al. Outpatient intravenous ketamine for the treatment of complex regional pain syndrome: a double-blind placebo controlled study. Pain 2009;147:107-15.) that reported a significant response in CRPS patients to IV ketamine across multiple pain parameters c/w placebo, so much that they stopped the study half-way because they reached statistical significance much earlier than expected, since everyone randomized to ketamine was getting better and everyone randomized to placebo wasn’t. Critiques: because they stopped early, small N. They studied patients up to 3 months post-infusion, so no long term f/u. Although pain measures dropped significantly, QOL/functional parameters – no difference.

Now I know that statistical significance does not equal clinical significance, but I think the data thus far support that ketamine infusions are effective for pain relief compared to placebo. In the right setting, in the right hands, presumably they are safe. Are they safer, as effective, or more effective c/w everything else we throw at CRPS… who knows?

 

[lobelsteve]

I think Schwartzmann is a dufus. Never met him, but he really pushes the ketamine coma. It is experimental investigational at this time. Not covered by insurance.

Maybe he can convince WC to pay.
Worst case is people in huge amounts of pain that have failed good care and then pay cash for this.

 

[RUOkie]

But the big issue with all this is "What are the long term outcomes?" Heck, Ketamine is a potent hallucinogen. It is rarely used as an anesthetic agent because of the profound dysphoria. Why would we use this in this type of pt.without clearcut, functional improvement?

On the listserve, many people are responding. "I use it but why don't insurers pay for it?" "They use it in Mexico, and in a clinic in Florida."

 

[ampaphb]

But the big issue with all this is "What are the long term outcomes?"

what are the long term outcomes of ESIs? facets? lumbar sympathetic blocks? stellates?

The reason your responses on the list serve were unreasonable is that NOTHING we do, other than lumbar RF, has any longterm outcome studies

 

[rehab_sports_dr]

I'd say that lumbar transforaminals also have long term outcome data, since the Riew study did look at 5 year follow-up to see if the procedure was still surgery sparing.

 

[RUOkie]

what are the long term outcomes of ESIs? facets? lumbar sympathetic blocks? stellates?

The reason your responses on the list serve were unreasonable is that NOTHING we do, other than lumbar RF, has any longterm outcome studies

No that is not true. There are long term outcomes in treatment of CRPS with SCI stimulators, with TENS, with desensitization and oral meds. Just not injections. I will tell you, that in my practice, I do not use stellates or lumbar sympathetic blocks for long term treatment. They are used primarily as diagnostic injections, as well as to "get them over the hump" to allow a desensitization program and force use program.

If these studies were using IV ketamine for acute CRPS, we might be able to show some significant functional difference. But to use a dangerous hallucinogen for last resort treament with people who have had CRPS for 7 years and the best study shows NO functional change, why would we spend our health care dollars for that?

When I review a chart for an insurance company or for a w/c IME, I would rather spend more money for something that really works as opposed to less money for something with no proof of efficacy.