My CRPS is in my right arm. I had a stellate ganglion block (in my neck). I did not get any pain relief from it and actually had my worse flare-up following the block. The flare started a few days after the block. The first day of the flare was not good but then the next day was just horrible. If I remember correctly my flare up only lasted a few days, but man what a few days it was.

I hope that you are feeling a bit better soon.