How will you be treated in a medical emergency if you are in a vegetative state? What if you suffer from dementia?

Many persons have a living will and advances directives. A whopping 37% of adults have one.

“Improving end-of-life care has been a national conversation for some time now, presumably because it will affect all of us at some point and is a very personal matter,” said senior study author Dr. Katherine Courtright of the Fostering Improvement in End-of-Life Decision Science Program at the University of Pennsylvania in Philadelphia.

A living will and advance directive are not the same.

Living wills. A living will expresses your preferences for end-of-life care but is not a binding medical order. Instead, medical staff will interpret it based on the situation at hand, with input from your family and your surrogate decision-maker.

Living wills become activated only when a person is terminally ill and unconscious or in a permanent vegetative state. A terminal illness is one from which a person is not expected to recover, even with treatment — for instance, advanced metastatic cancer.

Bouts of illness that can be treated — such as an exacerbation of heart failure — are “critical,” not “terminal,” illness and should not activate a living will. To be activated, one or two physicians have to certify that your living will should go into effect, depending on the state where you live.

DNRs. Do-not-resuscitate orders are binding medical orders, signed by a physician. A DNR order applies specifically to cardiopulmonary resuscitation (CPR) and directs medical personnel not to administer chest compressions, usually accompanied by mouth-to-mouth resuscitation, if someone stops breathing or their heart stops beating.

The section of a living will specifying that you don’t want CPR is a statement of a preference, not a DNR order.

A DNR order applies only to a person who has gone into cardiac arrest. It does not mean that this person has refused other types of medical assistance, such as mechanical ventilation, defibrillation following CPR, intubation (the insertion of a breathing tube down a patient’s throat), medical tests or intravenous antibiotics, among other measures.

However, many people do not inform their family that they have a living will and/or advance directive.

“Some people do fill out these forms with families or lawyers, and then the forms sit in the dusty recesses of a back drawer and they are not available or shared with family and friends, especially before they are needed,” she told Reuters Health by email.

It is also very important to make your wishes clear to your medical providers. Apparently, medical providers don’t assume to read the contents of a living will or advance directive:

“Don’t resuscitate this patient; he has a living will,” the nurse told the doctor, Monica Williams-Murphy, handing her a document.

Williams-Murphy looked at the sheet bearing the signature of the unconscious 78-year-old man, who had been rushed from a nursing home to the emergency room. “Do everything possible,” it read, with a check approving cardiopulmonary resuscitation.

The nurse’s mistake was based on a misguided belief that living wills automatically include “do not resuscitate” (DNR) orders. Working quickly, Williams-Murphy revived the patient, who had a urinary tract infection and recovered after a few days in the hospital.

Unfortunately, misunderstandings involving documents meant to guide end-of-life decision-making are “surprisingly common,” said Williams-Murphy, medical director of advance-care planning and end-of-life education for Huntsville Hospital Health System in Alabama.

An article in the New York Times raises another deficiency in many estate plans: the standard living will and advanced directive only apply after someone has been diagnosed with a terminal injury or illness or otherwise are in a vegetative state. IT DOES APPLY TO DEMENTIA PATIENTS. (A durable power of attorney will usually apply though.)

Not all experts are convinced another directive is needed. But as Dr. Gaster and his co-authors recently argued in the journal JAMA, the usual forms don’t provide much help with dementia.

“The standard advance directives tend to focus on things like a ‘permanent coma’ or a ‘persistent vegetative state,’” Dr. Gaster said. “Most of the time, they apply to a person with less than six months to live.”

Although it’s a terminal disease, dementia often intensifies slowly, over many years. The point at which dementia patients can no longer direct their own care isn’t predictable or obvious.

Moreover, patients’ goals and preferences might well change over time. In the early stage, life may remain enjoyable and rewarding despite memory problems or difficulties with daily tasks.

“They have potentially many years in which they wouldn’t want a directive that says ‘do not resuscitate,’” Dr. Gaster said. But if severe dementia leaves them bedridden, unresponsive and dependent, they might feel differently — yet no longer be able to say so. . .

Last year, the journal Demography published a more representative model, estimating that for the cohort born in 1940, the lifetime risk at age 70 was 30.8 percent for men and 37.4 percent for women.

Dr. Gaster tells patients that “somewhere between 20 and 30 percent of us will at some point develop dementia.” Over the past year, as patients turn 65 and qualify for Medicare — which covers a visit to discuss advance care planning — he has offered them his dementia-specific directive, intended to supplement their other directives.

In my opinion, a durable power of attorney could remedy many deficiencies in a Living Will and Advanced Directive.

Something new has arisen as well:

POLST forms. A POLST form is a set of medical orders for a seriously ill or frail patient who may die within a year, signed by a physician, physician assistant or nurse practitioner.

These forms, which vary by state, are meant to be prepared after a detailed conversation about a patient’s prognosis, goals and values, and the potential benefits and harms of various treatment options.

Problems have emerged with the increased use of POLSTs. Some nursing homes are asking all patients to sign POLST forms, even those admitted for short-term rehabilitation or whose life expectancy exceeds a year, according to a recent article by Charlie Sabatino, director of the American Bar Association Commission on Law and Aging. Also, medical providers’ conversations with patients can be cursory, not comprehensive, and forms often aren’t updated, as recommended, when a patient’s medical condition changes.

“The POLST form is still relatively new, and there’s education that needs to be done,” said Amy Vandenbroucke, executive director of the National POLST Paradigm, an organization that promotes use of the forms. In a policy statement issued last year and updated in April, it stated that completion of POLST forms should always be voluntary, made with a patient’s or surrogate decision-maker’s knowledge and consent, and offered only to people whose physician would not be surprised if they die within a year.