I wish I had the words to make you feel better but I don't. I can however offer you a great big hug.
My best advice is to seek out a lawyer, one who specializes in malpractice suits. This hospital should not get away with what has happened and your brother will require many medical services in the future regardless of which way his condition goes. Your family should not be carrying this burden alone.
My prayers go out to you and your family.