I work nights, and if my patient takes a turn for the worse or flat out dies and is not a code, I am the one to call and break that news to the family. If the patient codes suddenly, I am in the room helping, another available nurse will call the family.
In my facility, docs typically give bad prognoses, and will call the family if death is not imminent; but at night, when things can change suddenly, it's up to the nurses to keep the family informed and to break bad news.
It's not easy. I usually don't beat around the bush, because no one wants to hear a long drawn out story ending with "your husband is dead." I typically say something like "This is BluegrassRN from X hospital, and I'm taking care of your husband tonight. I am very sorry to tell you that he has passed away." I usually give them a little breakdown of what has happened, and then ask them if they would like to come up to be with him before the funeral home arrives. I ask them if there is someone I can call for them: a pastor, a family member, someone to be with them. I ask them if they have any questions. That's about it. It stinks to have to do it over the phone, but sometimes it happens that way.
If the patient is going down hill fast, or we are actively coding, I'll call and say something like "This is BluegrassRN from X hospital. I am calling to tell you that your husband has taken a turn for the worse. His breathing is much more labored/his heartrate and rhythm have become unstable/he is becoming more confused and less alert." I will give them my honest opinion of what the future holds "We may need to transfer him to the ICU/I fear that he will not be with us much longer."
In the event of a code, I usually say something like "We are currently working very hard to keep your husband alive right now. His condition deteriorated very fast/he had a sudden rhythm change at 3:15 this morning, and despite all our efforts his heart stopped. We are in the process of doing chest compressions and coding him as we speak. Are you able to come up to the hospital right now?"
It helps to have a spiel, a script of sorts. That way you don't use too many words, and you don't stumble over your words. I always ask if they have someone with them or if I can call someone for them; I always ask if they are planning on coming up to the hospital right now; I always ask if they have any questions; and I am always honest. If someone asks if they should come up, I am honest. "If it is important for you to be present if your husband dies, then you should come up now, because his condition is quite serious and I'm not sure he will pull out of this."
It's an uncomfortable conversation to have, but it is so important for the family to understand what is happening.