And, like in the Schiavo case, their loved ones eventually may have to wrangle with deciding whether that treatment is helping in the recovery or merely prolonging an inevitable death.

Feeding tubes ``certainly have become more prevalent,'' said Perry G. Fine, vice president of the National Hospice and Palliative Care Organization.

Fine said Wednesday that the exact number of patients who rely on feeding tubes in the United States is not known, but conditions such as stroke, dementia, cancer or Parkinson's disease can rob people of the ability to take in food.

There are several types of feeding tubes for the process that doctors refer to as ``artificial nutrition.'' As in Schiavo's case, a surgical procedure can create a hole in the abdomen to insert a tube that supplies nutrients. Other types of feeding tubes snake through the nasal passage or attach intravenously.

For some, feeding tubes can be like a bridge, keeping them nourished until they recover enough to eat on their own.

But doctors are discovering that feeding tubes don't always help patients who need them indefinitely, Fine said.

Medical studies in the past five years have determined that feeding tubes don't lengthen life or improve the quality of life when used for long-term management of patients who, for example, are recovering from a stroke or have conditions such as Alzheimer's disease.

``The reflex behavior was to put a feeding tube in everybody and keep them going because we thought it was doing good,'' Fine said.

``As it turns out, [feeding tubes] can cause more discomfort and more problem with providing care'' by causing serious digestive or respiratory problems, he said.

Prevalence in the use of feeding tubes tends to vary regionally across the United States, said Steven Levenson, a Maryland physician who is president-elect of the American Medical Directors Association.

Although medical research is discovering that feeding tubes aren't always good for patients - especially geriatric patients - that knowledge has not filtered to all parts of the country, he said.

Levenson compared nutritional intervention through feeding tubes to a car in need of gas.

``If you're going to a gas station and pouring gas into an engine that is malfunctioning, you can pour all you want to, but what good is it going to do?'' he said.

``If organs aren't functioning, kidneys are broken down and the heart isn't beating properly, nutrition is not going to fix that.''

Myra Christopher, president of the Center for Practical Bioethics in Kansas City, Mo., said she fears the Schiavo case will inhibit families and medical professionals from deciding to allow feeding tubes for critically ill patients.

For instance, feeding tubes can keep stroke patients alive in the hope they may get better within a few weeks or months. But families may become fearful that a feeding tube could not be removed if their loved one never regains consciousness.

``I'm concerned that families and health care professionals have been so unsettled by what has played out that they will say, `We won't put a tube in, we're not going there,' '' Christopher said.

She said the Center for Practical Bioethics has received thousands of phone calls and e-mails in recent weeks from people who are concerned that their living wills aren't valid because of events in the Schiavo case.

Schiavo's legacy may be that her plight has sparked awareness of the need for families to talk about end-of-life issues, Christopher said.

In Tampa, people such as Lisa Pritchett have been watching the Schiavo case closely. The case reminds her of a similar painful decision that she had to make last year.

Pritchett recently moved to Tampa from New York because of the death of her husband, Byron.

After a snowmobile accident in 2004, Byron was left with extensive neurological damage. Doctors told Pritchett he would not recover.

He did not have a living will, but Pritchett says he told her when he was alive that he would not want to be kept alive through artificial means. She allowed him to be taken off a ventilator after one month.

In addition to enduring her own ordeal, Pritchett saw other patients at the hospital and how their families coped with decisions about life support.

``They weren't what you would think; they were people in their 40s and 50s who had strokes or accidents.

``My brother and I would talk about it. We said that anyone who didn't think they needed a living will should just come spend some time in'' an intensive care unit.

Reporter Susan Hemmingway Johnson can be reached at (813) 259-7951.