If I become dad's legal guardian and he doesn't get Medicaid, will I be responsible for his medical expenses?

My father was living with me, but has become mentally incompetent. I applied for temporary guardianship. He is in a short term mental facility and only has Medicare. I've applied for Medicaid for him, but haven't been notified if he will get it. If I become his legal guardian and he doesn't get Medicaid, will I be responsible for his medical expenses? He has a small life insurance policy and Social Security in the amount of $800 per month. I'm trying to decide if I should do the permanent guardianship. I don't want to lose my house and all my assets because I have to pay his expenses. Please help. Thank you.