Who or what determines the need for hospice?

Usually you discuss this with her Doctor and Palliative care Maybe a Option. try and get a social worker involved who can help you . After speaking with My brothers psychiatrist and then the Head doctor at the Cancer center we agreed it was time for hospice . The cancer had gone to his brain and The tumors had grown and spasms , difficulty breathing . My Mom was having trouble swallowing too - dont Have a feeding tube inserted - the anesthesia gave her a heart attack .

Speak with those at your care facility. And with whatever medical team is in place at this time.
The facilities are often connected with Hospices and you may even be able to discuss with them.

If you are looking at swallow deficit now, I am so sorry to say that you are either looking at aspiration pneumonia or the option of tube feedings which I hope you are not considering. The inability to accept nourishment does come, and it does fortell the end being near.
If nourishment cannot be taken then Hospice would be on board for only a week to a month before they are no longer needed. They have medications to cut secretions that cannot be swallowed, and can be a whole lot of comfort. When one cannot take adequate nutrition the electrolytes are affected and organ failure with all it problems of increased confusion and agitation occur.

Hospice is end of life care. I am not your doctors, your medical team, your care facility, but all of those can advise you together when you could benefit by this extra care, and when it is looking as thought the qualifications are met (death is expected within a six month period). Do know that Hospice re-evaluates as they go and then at six months as to whether the extra care and support are still needed and as to whether the end stage is there.

Now is the time to make an appointment with the administration of your wife's facility to discuss.
I am so very very sorry. This is hard news for the new year.

You can ask for a Hospice evaluation.
What happens is the doctor will certify that if the course of the disease progresses in a "normal" manner she has 6 months or fewer.
That said if she lives past the "expected" time Hospice can recertify her and she can remain on Hospice.
What Hospice will do in a facility is the Hospice Nurse will see her 1 time a week. and the Hospice CNA's will take over the bath or shower that the facility would normally do. there are Hospice Volunteers that can come in and visit with her if you wish. The Hospice Chaplain can come in and visit with her is you wish. And the Hospice Social worker can answer questions for you, help you through any problems.
I feel that it is worth it to get on Hospice as soon as possible. Hospice is covered by Medicare, Medicaid and most Insurance so taking advantage of it you are getting more "bang for your buck" so to speak.

You don't want her to enter hospice until it's necessary.

Be assured that hospice won't take her until it's necessary. Understand that hospice isn't a bad thing for the patient, it's a good thing because hospice knows how to keep patients comfortable. Hospice can advise you so that your questions are answered. Hospice provides reassurance for you and for the patient.

Start with people at the MC unit and/or wife's primary care physician, who can get the ball rolling. Also, I've known people who called a hospice company directly to ask for an evaluation. I actually met a hospice social worker when my mom was in rehab after a fall, and she helped get the paperwork started for us.

From what you tell us, it's time for hospice now.

I'm very sorry that your wife is so sick.

I initially called hospice in myself for an evaluation for my late husband in mid 2018, and was told at the time that he didn't qualify for hospice but did qualify for their palliative care, which isn't much help at all so I turned that down.
Then in late 2018, my husband developed aspiration pneumonia and almost died and developed sepsis and septic shock.
He then qualified for hospice care and came home under their care for the last 22 months of his life.
You can talk to your wife's doctor or just call hospice yourself to see what they say, but I'm guessing your wife will qualify now for their care. And it will not only be extra sets of eyes on your wife with a nurse coming once a week to start, and aides coming at least twice a week to bathe her, but they will also supply any and all needed equipment, supplies, and medications your wife may need all covered 100% under her Medicare. Plus you'll have access to their chaplain and social worker.
I think most people wait until the very end to bring hospice in, when in reality they should bring them in much sooner.
I wish you well as you take this final journey with your wife.

In my mom’s rehab the respiratory team and PT/OT recommended hospice, but ultimately a doctor had to sign off on it. It helped that my mom was conscious and able to agree to it. I wish you the best.

In my experience, Nurses are not allowed to mention Hospice. Usually a doctor will. Its time for Hospice now. Not being able to swallow is the body starting to shut down. Once that happens, no food or drink should be given because the body no longer processes it. Hospice will keep her comfortable, pain and anxiety free.

Tell the Nurse you want Hospice brought it. She will get the doctor to sign off.

Usually the nurses or doctors at a facility can tell when end of life is approaching and let you know they think it's time. As for the swallowing - staff there should know all about dysphagia (swallowing difficulty) because it is common in late dementia, modifying her food and beverages in order to help her eat should not be something you have to ask for.