I guess I'll be adding my unpopular opinion ...
My dad told me he filed a DNR during our last telephone call, and said he wanted to go "quickly." I was a bit upset with him and said it would be "nice for him, but not us!" He told me not to worry because he wasn't sick and all his check-ups were looking good. He was only 72. His dad lived to 87 and mom till 92.
He died from cardiac arrest, while in the emergency room, exactly 1 month later. I had not seen or talked to him since that last call.
For 6 weeks, I was a wreck because I imagined doctors stood around and watched him flat-line. They could have saved him, but they just watched him die instead ... because of that stupid DNR!
Then I finally got the courage to ask Kaiser for a copy of his last 2 years of his medical record, and the records from the emergency. Since I'm his daughter, they sent them to me.
What I learned is that, yes, they did ignore his DNR. For over 1 hour, they gave him CPR, they defib'd him at least twice, they intubated him, they gave him IV fluids to get his blood pressure back up, painkillers, other heart meds. He still died 2 and a half hours after he arrived at the emergency room.
Ever since I learned they ignored the DNR did *everything* they could to save him, I've felt more at peace.