My grandmother is having a bipolar manic attack and I don't know what to do?

I live with my grandparents and my grandmother is bipolar. She hasn't had a manic attack in a while but she seems to be having a semi-severe one now. She's yelling and talking to herself and crying spontaneously. I'm alone with her since my grandfather has to spend the majority of the day at the hospital for dialysis treatment and I've never had to be alone with her during her attacks.