Where is the hotel?

US hotels have back-up generators that will allow the locks to continue to work. Suspect most hotels in Europe and Asia, esp in larger cities, have the same. If they have not already, I would recommend your family try to get into their room with their room key to get the medical equipment.

Some hotels also have a master keyed entrance to the rooms as well. Can you contact your family to have them go to the front desk to have someone manually unlock the room if they can't get in with the electronic key?

Good luck!