My FIL (92) cares for his wife(82) who has dementia. FIL still drives himself to Dr. appts, etc. He wants someone to come and sit with his wife when he is gone more than an hour or two. He can give a weeks notice on these sittings. Is there any service that provides basically "on call" senior sitting?
If the wife is on Hospice all Hospice have Volunteers that can come sit with a patient for up to 3 to 4 hours. They can not do any "hands on care" though.
If your FIL has been a member of a religious organization some also have Volunteers that might do this as well.
If there is an Adult Day Program in the area it might be a good idea to get MIL involved so that FIL gets a break a few days a week and then he can schedule his appointments on the days that she would be attending the Adult Day program.