Maximum Bupivacain dose

I'm a c5-6 complete. Like many of you, I battle chronic pain. I have a Medtronic pain pump and am trying various meds. So far, narcotics seem to do nothing but produce side effects. Bupivacain, however, seems to be helping some. It's really tough to tell with highs and lows but seem to be having fewer really bad days. The current dose is 8.8 micrograms (I think is correct unit) daily.

Does anyone know what the maximum dosage may be?
Anyone have good luck with this medication?

Thank you in advance for any feedback. I greatly appreciate the time so many spend providing information.

Maximum Bupivacain dose