I am using Ketamine topically. I have a 5% Ketamine cream that I apply to my foot (my most affected area) as needed up to 3x a day, and it really does help. No one has offered the IV Ketamine, I believe they tend to wait for that as a last ditch effort around here. I've been offered Pamidronate (sp?) as an infusion.
I have read many accounts of Ketamine infusions being very helpful, but that they also have to be continued at certain intervals. I don't know that W/C would pay for it, but you can always ask (If your treating doc feels it is appropriate).

I did have a doctor talk about peripheral nerve surgery, but he also cautioned that it would likely be of limited use. Plus, any surgery w/CRPS brings along risks of spread, so that has to be considered as well.