I too have the same issue with pain meds and having an immediate response from my neurotransmitters essentially "recognizing" the compound. Additionally, my brain will create more pain with the elevation in pain meds I ingest, so I just don't really take any. I think you and I are floating in the same leaky boat. As for Ketamine comas, I, before being forced into disability from my position as medical clinical director (though not a physician), I came to be very familiar with the process of Ketamine use. It is a heavily used "club drug" in Canada and a horse tranquilizer here in the States. When used in short infusions, for about two hours, along with a sedative to suppress disturbing dream states, the drug is believed to "reset" the neurological system from the physical body effects of RSD.
Typically, patients will be ordered for 5 to 10 days of 2 to 3 hour infusions, during which they are completely sedated. The sedation is necessary due to the "key hole" the patient enters. Look it up-it's why I won't be doing it. The actual psych term for the "key hole" is "dissociation"and can be quite upsetting if the patient isn't sedated enough. BUT, if the right drug combination is given, there have been some excellent results and outcomes, with some patients reporting serious decreases in RSD symptoms or even complete remission of the disease in just days or weeks. Patients may have to come back once every 3, 6, 12 or whatever monthly frequency the physician orders in order to "keep the disease under control". For others' Ketamine doesn't provide any relief or a level worth the trouble of the infusion. remember that all treatments are subjective in success rating.
I should note that the "Ketamine coma", during which the patient isn't awakened AT ALL for a full five days or so from the Ketamine infusion, IS illegal in the US. Alternatively, if the patient is awakened daily by lessening and stopping the administration of the drugs while being monitored in an ICU, the Ketamine infusion CAN BE legal. Another note is that NO INSURANCE will pay for the Ketamine infusions, be it during a two hour or a twelve hour period. All are cash payment services paid for by the patient. There may be a rogue insurance company out there paying for a Ketamine treatment somewhere, but they are not the norm. Ketamine was only recently outlawed overseas in Germany after the death of a female RSD patient who sadly died during a week-long Ketamine coma. It has never been legal here in the U.S. to administer Ketamine for more than a portion of one one day while in an ICU. Ketamine can be administered via injection/drip or nasal inhalant.
Some of us with a diagnosis of RSD are stuck with essentially no pain relief (like you and I, Kevscar, who rate our pain on a scale from 1 to 12 instead of 1 to 10, per my pain management neurologist), some do Ketamine utilizing their own personal savings (sometimes supplemented by fund-raisers, second mortgages, etc.).
Some lay in bed, day after day swallowing pain meds and potentially fueling a possible addiction. There are so many levels to this disease and not much support. We need each other and this site is a great place to find one another. I thank each and every one of you for your time and friendship. It is a true thing of beauty that in a time of solitary darkness and merciless pain, I can find my way here and see the light of friendship. Thank you.