The coronavirus pandemic has been a stark reminder "that things can change in a minute — and so you've got to be prepared," says Sunita Puri, medical director for palliative care at the Keck Medical Center at the University of Southern California. One of the ways to do this is to decide what sorts of treatments you would want (or not want) in the case you became critically ill — and then document those wishes and share them with loved ones.

COVID-19 has now killed nearly .04 percent of the U.S. population – and sent an even higher proportion to the hospital for intensive treatment. But many – some 63% of adults in the U.S. – have not made formal plans for what they would want their critical care and, if it comes to it, their deaths, to look like.

Puri says, working in palliative care, she's seen numerous examples when careful end-of-life planning, done in advance of a crisis, can make a big difference. For example, the daughter of one COVID-19 patient had already discussed these issues with her mother — before the mother became critically ill — and that helped the daughter and the medical team make decisions and removed some of the strain around deciding whether to continue invasive care.

As a doctor, "you always want your recommendations to be in alignment with what the patient would want, what their values are, what their preferences are," says Trevor Bibler, a faculty member at Baylor College of Medicine's Center for Medical Ethics and Health Policy. Lacking that information when loved ones and medical professionals need to make difficult decisions in a time of strain "can be an additional area of distress," he says.

So preparing some simple paperwork – and having a few important conversations – is more crucial than ever, say experts in palliative medicine and bioethics. Here's what you need to know.

Find advance directive forms for your state

A first step to take is to complete an advance directive. This is a form that allows you essentially to check boxes about what kind of life-sustaining interventions you want – or do not want – such as being resuscitated or having a feeding tube. These are legally recognized documents and typically require witnesses (and sometimes a notary). These forms and their questions vary for each state; a comprehensive list of state forms created by the National Hospice and Palliative Care Organization is available for anyone for free from AARP.

Contemplate your goals and wishes

When filling out your advance directive, take some time for introspection. Remember this form might have to speak for you in a moment when you cannot speak for yourself.

Also be aware that these forms do not always provide an entirely clear path for care, Bibler notes. "People think that, 'Well, if I fill this out, then it's going to be completely unambiguous as to what's going to happen to me at the end of my life,' " he says. "But oftentimes the advanced care planning documents are hard to interpret, or the clinical situation might not be exactly what people think."

That is in part because the forms try to capture your wishes in the simplest terms (no resuscitation, for example). But life — and particularly critical care and death — is complicated and incredibly varied. What you might have seen a relative endure (perhaps a slow decline through advanced dementia) could be very different from a situation you might face (such as a rapid and severe coronavirus infection).

One way to help others understand your wishes is to think about what your idea of good and bad critical care would look like for you, Bibler says. "Don't just rely on a couple of check boxes" on the form, he says. "Add additional narrative elements" that illustrate your goals. It could be as simple as noting, "If I can never interact with my grandchildren again, I would rather be made comfortable,'" he says. "That's a very helpful narrative element that gives a lot more insight into what the person valued."

Thinking about clinical decisions, such as whether we would want mechanical ventilation and in what situation, can be hard "because we're not medical experts," says Rebecca Sudore, a palliative medicine physician and professor at the University of California, San Francisco, School of Medicine. "But what we are experts on is ourselves and our lives. We're experts about what brings us meaning and quality of life."

To help people in thinking and talking about these issues, she and her colleagues created a research-based online resource called PREPARE, which is available in English and Spanish and includes state-specific advance directive forms in multiple languages.

It might also help to remember that this planning is not just for you. "It's really all about helping your family and friends," Sudore says.

Consider the ventilator question

Even if you have filled out advance directives in the past, now might be a good time to review them to make sure they reflect your current wishes, Bibler says. Some people might change their minds about whether they would want to go on a ventilator if they got COVID-19, how long they would want to stay on ventilation without signs of improvement, or if they would feel good about offering their ventilator to another patient who had better odds of surviving should there be an equipment shortage.

COVID-19 has made the ventilator question particularly urgent. Ventilators are machines that can help you breathe if you can't do so on your own, which can happen in severe COVID-19 cases. Mechanical ventilation can sometimes be lifesaving but is also highly invasive: A tube is inserted in your throat to force air into your lungs.

Anytime you go on a ventilator, there's a risk you won't improve and will spend your last days or weeks unable to speak and heavily sedated.

Early in the pandemic, it looked like going on a ventilator was a long shot in terms of survival. Studies showed a minority came off the machines alive. But more recent evidence has been somewhat more promising. For example, a study in The Lancet showed that of 203 critically ill COVID-19 patients who were put on ventilators in New York hospitals, less than half (about 41%) had died a month after follow-up.

A study conducted in several intensive care units in Atlanta found that of 165 ventilated patients, 35.7% died, with fewer than 5% still on ventilation at the end of the study.

And as more information comes out about COVID-19 treatment, you might decide to opt for different treatment preferences. Advance directives can also be revised again after the pandemic. "People change their mind about what they want at different times," Bibler says.

Pick multiple health care agents

Another important element of critical care planning is naming at least one health care agent (also called a proxy or surrogate). These are people (named in your advance directive) who you designate to make medical decisions on your behalf if you are incapacitated and cannot make them yourself. And they will be designated in a particular order so only one person acts as the official agent at any one time.

Bibler recommends naming as many backups as possible, especially during the pandemic. For example, entire families are getting sick, so having additional individuals who can fill that role should a first or even second agent become ill is particularly helpful now.

It is important to clarify that although appointed health care agents are allowed to speak on your behalf, completed advance directives usually take precedence over their words, Bibler says. In fact, even if an agent insists that their loved one would have wanted a different approach than is outlined in a directive, doctors can face liability if they go against the legal document. This is another reason to review advance directives regularly and ensure they still align with your wishes — and to let others know if you have changed anything. Bibler also recommends "letting them know why there has been a change," which can help everyone make more nuanced decisions later if necessary.

It might also be worth considering if there are people you would not like to have contributing to decisions on your behalf. "There's always going to be that person that just shows up" when critical decisions need to be made, says Puri, who is also author of That Good Night. "There's not a specific box for this, so I suggest people just write it in."

Have "the talk"

Set up time to tell your appointed health care agents that you've named them and talk through your decisions, Sudore says.

"I can't tell you how many conferences I've had with family and friends who basically didn't even know their name was written on an advance directive so they can't even prepare themselves," she says. "And giving these people even just an inkling of what's important [to you] can really help."

Experts say that conversations with your most important loved ones about your care wishes are incredibly helpful. (And the more people you loop in, the better, Bibler says.)

The conversation doesn't have to be gruesome, Sudore says. If it's easier to steer clear of resuscitation or ventilation details, some other topics might prove to be more useful, ultimately, for making care decisions, she says.

For example, she says, you can tell people: "These are the things that make my life worth living and give me quality of life – and these are the things that if I didn't have it would be really hard on me."

These planning conversations might not be easy, but they are key to giving us more say in care decisions. "We have a semblance of control if we can plan a bit," Puri says. "There's a lot more suffering when nobody has planned for anything."

Katherine Harmon Courage is a freelance science and health journalist and editor, contributor for Scientific American and Vox, and author. You can find her on Twitter at @KHCourage.

Copyright 2020 NPR. To see more, visit https://www.npr.org.