Everyone dies eventually, but sadly the days of anyone being able to simply slip away peacefully in their own bed when their time comes is long gone. Dying today (in the UK, at least) involves a sea of acronyms: DNACPR, ReSPECT, TEPs, POA, ADRTs.
And whilst few of us enjoy contemplating our own mortality - or that of family members or loved ones - if we don't engage, there's a very high chance that yet another person will be exposed to totally inappropriate resuscitation attempts when their body has decided that it has lived its time, and it is time to stop... ordinary dying, as it should be.
So what are the basics? (UK situation - there are similar, but different, provisions in the USA)
Doctors happily argue for hours on Twitter about what is the most important/first thing to discuss, but frankly, it doesn't matter. There mere fact you're reading this is a good step. But personally, I'd start with a Do Not Attempt Cardiopulmonary Resuscitation (DNACPR) form and work backwards from there. Everyone whose death is expected (e.g. severe frailty, terminal illness) desperately needs the protection of a DNACPR in place as soon as possible.
But there are many other people for whom death does not seem imminent, but for whom the protection of a DNACPR would be very sensible because CPR would be either inappropriate/unlikely to succeed (multiple medical problems, and also great age... is death ever really a surprise if someone is in their 90s?) or simply unwanted - if I had a pound for every very old patient who has said to me they are fed up with life and just want to join their (deceased) spouse I would be a rich woman.
There's also plenty of evidence that the likelihood of a good outcome after cardiac arrest in old people is very small; that cognitive impairment in survivors who are "successfully" resuscitated is very common, and a very recent paper by a team from Taunton, UK (September 2019) movingly describes that that survivors (and families of survivors) of over-80s who have been successfully resuscitated after cardiac arrest often regret that resuscitation was attempted.
Outcomes after cardiac arrest for people with living with frailty (which may be as "mild" as needing help with housework/shopping etc) are even more dismal. We are awaiting large registry data, but as a example in two recent case series, survival in patients living with frailty who had had an in-hospital cardiac arrest was 1.8% in one series and 0% on another.
We should all have Lasting Power of Attorney in place (for Health & Welfare, but also for financial matters) regardless of our age and health status, in case we become incapacitated for any reason (any of us could get run over by a bus, as our mothers liked to tell us) and, although most people use a solicitor for this, that's not essential: the relevant government forms are available in English or in Welsh.
If you know there are treatments you would not want under any circumstances (for example, being artificially kept alive after a catastrophic brain injury) then you need an Advance Decision To Refuse Treatment (ADRT), which are sometimes referred to by the nickname of a "Living Will". When correctly completed they are legally binding - doctors cannot ignore or over-ride them if they are both "valid" and applicable" (used as specific legal terms) but you'll probably need to seek advice to make sure yours is legally watertight- and beware, some templates available on-line are not, especially older ones. Try the Compassion in Dying website for more information.
Family members - even when legally empowered by being appointed with Powers of Attorney - often find it very stressful to make decisions that influence withholding treatment. So if you know, for example, that you would not want to be artificially kept alive by artificial nutrition/hydration after a catastrophic brain injury or being diagnosed in a Persistent Vegetative State, then it would be wise to cover this possibility with an ADRT - and specify it cannot be over-ruled by whoever you have given Power of Attorney too.
Finally there are things like ReSPECT and Treatment Escalation Plans (TEPs) - the name of the latter may vary locally - which aim to describe what is the clinically appropriate and/or wanted "ceiling of treatment" for an individual patient. So, for example, someone nearing the end of life may not want to go to hospital, or it may be clear that a person doesn't have enough physical reserves (or onward prognosis ) to survive the discomfort, pain and risks of a stay in Intensive Care.
Links for further information (UK):
Age UK's information on Power of Attorney
Compassion in Dying's information on Advance Decisions to Refuse Treatment (ADRTs)
Information on ReSPECT forms
Links for further information (USA)
The Mesothelioma Center has a really useful summary of the equivalent processes/forms/acronyms in use in the USA
WARNING - please take care when Googling these issues. Subject matter expert Celia Kitzinger warns, "There are sites to AVOID because they confuse ADRTs + advance statements, charge for ADRTs or are marketing unnecessary legal services. Some websites give misinformation about the law or medical practice. Some provide misleading templates".