You have the right amount of HP for Vistrathis, r1. I don't know if you're also keeping track of healing surges, but see my mini-stats below if you need them
Vistrathis - Githyanki Swordmage 4
Passive Perception 12, Passive Insight 12
AC 24, Fort 17, Reflex 18, Will 17
HP 45/51, Bloodied 25...