Side note: when I had NA procedures done last year on both hands by Dr. Denkler he used a local anesthetic and it was a good thing he did as after the incisions he bent my hand to over 180 degrees to loosen the chords. This would have been very painful.

Without the local during the NA procedure I could envision patients moving their hand in response to the pain and this would seem likely to actually increase the risk of nerve damage with this procedure.

In part I understand that with nerve dense locations medical practitioners have to weigh the pain from injecting a pain killer against the pain caused by the procedure. Sometimes it may be a trade off. Other times doctors may be more interested in saving time by not having to wait for the anesthetic to take effect.