Before you measure the furniture, decide which room the bed goes in. Every room is a set of trade-offs the house has already made for you. Count what each room gives, and then choose.
Local option: New Plan Care gives families in the St. Louis area in-home help so a parent can stay home: companionship, help with bathing and dressing, meals, and overnight care. Call (314) 405-0887.
Write down who sleeps where
List the person on hospice, the person who will sleep closest to them, and anyone else whose sleep you have to protect. Note which rooms the family uses in the night, and how far each of those rooms is from the bed you are considering. A room at the end of the hall may be quiet and far away, which can be exactly what you need, or it may mean the caregiver cannot hear the bed from their own room.
Count the outlets before the bed
The bed needs power, and so may a lamp, a phone charger and any equipment the agency supplies. Count the outlets on the wall the bed will sit against and note which circuit each one is on. Do not run equipment from an extension cord unless the maker allows it, and do not plug several heavy items into one strip. If the room has too few outlets for what you need, that is a fact about the room, and a licensed electrician can tell you what is possible.
Measure the walk to the bathroom
Walk the route from the bed to the bathroom door with a tape measure in hand, and time it at a slow pace. Note rugs, thresholds and the turn at the door frame. If a commode or a chair will be used in the room, measure the route they must take too. A room that looks close on a floor plan can be a long, tight walk with a cord across it.
Check the room on all sides of the bed
A caregiver has to reach the bed from more than one side. Measure the clearance on each side using the bed's footprint in the maker's listing, not the room's width, and leave space for a chair, a table and a person to stand. Check that the controls can be reached from both sides and that the bed can be raised or lowered without hitting a dresser or a wall.
Check the door, the window and the heat
Note which way the door swings and whether the bed can sit so the door clears the bed when opened. Note the window side and the light it lets in at different times of the day, and whether heat from a vent reaches that spot. Put the two candidate rooms side by side and write the answer to each of these questions for both. Choose the room that answers the most of them, and the one the family can live with in the middle of the night.