Hi Colin,
I'm so sorry for your suffering with this CRPS! I feel so upset for you at how far it spread! It can be hard for others to understand the range of pains with this. At least you will get good support and advice here. Glad you found this site
I too have CRPS in my left hand and arm after broken wrist and surgery in December '12. I started having terrible "complications" within 2 weeks and luckily my Physical therapist knew what it was and reported it to my Doc about a week later.
In addition to the RX meds. I heard Vitamin C helps prevent spread so I started at least 500 mg. a day, Magnesium 500 mg. (helps inflamation and constipation from opiates) and vitamin D3. Most of all DO NOT PUT ICE OR COLD on CRPS limb, you probably already know that.
How many nerve blocks have you had? Have they helped and how long do they last? I've had 5 with various results.
Keep us posted, good people here.