Joe, I had that nerve block too (+ sedative). Didn't last 16 hours though, and no aftereffects at all.

I had surgery on April 25, 2002 on my left hand with major involvement of the little finger and also the ring finger.
I also had a axial block in the armpit. The surgery went very well using the open palm method. During the recovery period I would experience "shocks" in my hand. I never knew when they would hit but sometimes they would hit hard. I asked my Dr. (Thomas Reilly in Akron Ohio) about it and he told me that he had to move the nerve and the tendon around to get all the DC so that was the reason for the "shocks" that it was the nerve(s) regenerating themselves. I also had lost the feeling in the affected fingers. After about 6-8 weeks the "shocks" stopped and everything is fine. The feeling eventually came back just like the Dr said it would. Just to be sure ask your Dr.about it. I have to see the Dr in January most likely to schedule surgery for the right hand. Also check your hand for new growths. I had one appear in the web of my thumb on the left hand surgery about 6 weeks after surgery.