For a local, CFS patients generally do better with an anesthetic without epinephrine. I had an extraction recently without epi and it was fine.
Epi is added to prolong the effect of the novocaine or whatever numbing agent. Most dentists now are used to people not tolerating epinephrine for various reasons. There is also a high prevalence of CFS patients who don't do well at all with nitrous oxide (laughing gas).
If you are amendable to homeopathics, arnica is good to prevent bruising and swelling, and ledum to reduce pain and tenderness at the needle
injection site. One can take a few pellets under the tongue of each right before the procedure, directly afterwards, and then every hour for four hours. Then as needed. Bach Rescue Remedy (or Five Flowers) as needed as well just to calm the shock of it.
I have found those remedies to make the entire recovery process so much quicker, more easeful and less painful.
Best wishes! Sorry to hear he just had appendicitis and now this