Four siblings-one with serious hospital stay has no children or wife. Who is assigned to POA if he is unable to make decisions

Don't know the rules in Ohio, but in the absence of a POA, usually it's next of kin that makes the medical decisions in which case you would all have equal standing. The hospital administrators or the social worker should be able to tell you the rules in your state.

Not 100%. I would say about 50-50 for the past week. I have forms but he isn't well enough yet. So who calls the shots in the hospital? The 3 or us, or only the oldest sibling . OHIO

Be sure to get the forms for your state and see if they have to be notarized or require witnesses. States vary in their requirements. The healthcare proxy (POA) is often part of the advance directives -- something he may want to consider.

Is he still competent mentally? If he is, he can choose a person to act as an agent for him. Only he will be able to appoint a POA for himself. If he is competent, talk to him about choosing someone for his healthcare and business POAs. They are two separate things, so can go to different people.