For the past few years I have occasional near-fainting episodes diagnosed as venovegal reflex. Most episodes pass after a few minutes. Recently, following a skin lesion removal with numbing by lydocane injection in the scalp behind the ear, I experienced a very strong lightheaded episode for about 6 hours (about as long as the numbing lasted). My adult son, who tends toward fainting from needles, relates a similar experience from a novacane tooth treatment.
Is there any literature connecting such numbing agents to venovegal reflex triggers?