I think the medical bills could be more of a problem than the credit card debt. You should probably speak with an elder care attorney now.
If you'd like to discuss, please feel free to call. Jeff Gold Gold, Benes, LLP 1854 Bellmore Ave Bellmore, NY 11710 Telephone -516.512.6333 Email - Jgold@goldbenes.com
I do not see a bankruptcy case as a necessary at this time. Based on what you have said, the debts will pass with your father and your mother will be ok.
Your parents would likely benefit from an elder care or estate planning lawyer, before their situation gets worse, if they have not done so.