I'm not a doctor or nurse, just a former paramedic, but I've seen enough death (family and otherwise) to be familiar with some of it.
Generally, a doctor isn't going to "battle" to save someone who is quietly dying of old age.
Why? Because there is nothing to treat, and most people prefer to approach age-related death with some degree of dignity and comfort, rather than have their last days/hours filled with uncomfortable and invasive "treatments". (things like IVs, intubation, etc)
That doesn't mean they'd sit back and do nothing, just most families would rather let great-grandpa go to sleep peacefully and simply not wake up, rather than subject him to the less than fun experience of "heroic measures" that may, or may not, work.
Medical personnel will treat the symptoms and diseases that exist. Old age is not a disease. There is no cure. So they could only treat whatever problems the man presents with.
The cause of death, while natural and age-related, is still likely to be cardiac, or other organ failure. Unless the patient was in a nursing home, or had some medical issue/emergency, death of this variety usually happens without medical intervention.
If the patient has had a heart attack, or stroke, or severe shortness of breath, or things of that nature, he would have been taken to a hospital (possibly treated in the emergency room, possibly admitted). The doctors would treat the relevant symptoms and would, if another incident happened while the patient was there, of course battle to save the patient's life.
As for what treatments and medications - I'll leave that to the doctors and nurses here - but that would greatly depend on the cause, and what the patient and/or their family wanted.
On telling the family - that depends greatly on the type of facility. A large hospital in a city might have a chaplain, or other trained personnel who could be the one telling the family. They often have private rooms for family members to gather out of the way (and without the distractions of other patients/families). A smaller facility, or one in a less populated area, the doctor might be the one to share the news.
Most medical personnel will use fairly straight forward terminology - they will say the patient died, not "passed on" or other euphemisms. A chaplain, or doctor who knows the family personally might be softer about it. But they're all going to say pretty much the same thing: I'm sorry, we did everything we could.
Death, even from age-related natural causes, is never quite so simple.
