Hey Cyn - The block itself lasts 4-6 hours - so ANY relief beyond this is considered a positive result!! And with each successive block the looked for result is for this relief period to be longer and longer - which is why they do a series. The earlier RSD is treated with the blocks, the more likely a real remission can be achieved, (that's the 6-month window talked about, which may vary a bit per individual, it's the period in which the RSD is still said to be sympathetic-maintained or mediated), but even later, RSD can be calmed and made much more tolerable via blocks. It's a very individual response however.

I was only under for one SGB, the one done in Denver prior to rib resection. The 3 done at the local pain clinic I had a numbing gel applied to the site, a local injection of anestheic, then the SGB. Fluoroscopy was ALWAYS used - this is a MUST imo.

Past the early phase of sympathetic-maintained RSD, it is said to be sympathetically independent - at this point I believe it is more centrally maintained - a change has taken place in the CNS. For this reason, a sympathectomy usually is NOT effective, as the sympathetic nerve ganglion is no longer the seat of the problem.

If you recall, I had 6 weeks or so free of RSD pain and sx folowing rib resection - thought it was GONE (oh joyful thought!). Then it came roaring back, twice or triple what it had been before. This is the usual pattern following most any surgery when you have RSD - in areas where there is lots of nerve involvement. (I had NO difficulty following my gall bladder removal, though the surgeon dismissed my RSD concerns and no additional precautions were taken). What is interesting is the period of weeks of total absence of both pain AND sx -no sweating, discoloration, tremors, temp changes, allydonia, etc. I think the ketamine coma actually works in a similar way, but for a longer period - shut the whole system down, apply general anesthetic to the CNS. Do this for the correct amount of time, figure out a way to keep the rest of the body/brain from harm while doing so, and perhaps you can return the system to it's original (rather than hyper-excited) state.

I think ketamine, at this point, is too dangerous a drug for wide-spread use as a treatment, although it is the first to offer real hope. I'm not keen on the idea of "coma" as any kind of a treatment option, frankly. But an in-patient regimen of 2 weeks of IV-sedation (deep sleeping, perhaps waking only for meals and Dr visits), along w/a controlled and individualized dosage of a CNS-moderating (or calming) drug (either one available now or as yet to be developed) could be offer real hope for many of us who cope with this most miserable condition.