Re: brain hernia
Have your doctor's office call with the diagnosis....I find that is the fastest way to get things moving.
Yes, any kind of brain herniation can be life threatening but it sounds as if he has something that is fairly stable. Stressing him to get in sooner might do more harm than letting him wait for a day.
So push the doc's office to get on the ball and get the referral going...NOW. They are the ones holding things up. They need to do their job and the faster the better. Since they are holding up the referral, they can call with the diagnosis and get you the first available appointment.
Push them, not him.
And good luck. My prayers will be with you both.