Patsy - my pump is mostly for dystonia rather pain. My primary pump med is baclofen, which is a muscle relaxant, and mine also contains bupivacaine, which is a local anaesthetic. My experiences with it have been pretty positive - I was almost completely wheelchair-bound before we found the right maintenance dose, but the difference it's made for me has not been to pain levels so much as to freeing up some of the muscles in my lower legs and feet.
this page is various photos of my CRPS, including where my pump is located. They don't usually stick out that much...I was recovering from a life-threatening episode of gastroparesis (also the result of my CRPS) when that was taken and I think only weighed a little over 30kg at the time!) I have to take additional medications as I said - Oxycodone as both ER and IR, Topamax (an epilepsy medication) and Mobic (an anti-inflammatory).
The ketamine infusion uses low doses of the anaesthetic drug ketamine - the same as the one in your cream - given intravenously over 5-10 days. The idea is that it blocks certain receptors and can help to relieve CRPS pain by 'resetting' the central nervous system. It's a rough ride...I've had four of them and none of them have been nice. This last one was a waking nightmare - like being in a black hole of panic and despair - but that said, it gives good pain relief for a lot of people.