Doctors too often miss chance to prevent deadly blood clots

WASHINGTON -- If you're lying in a hospital bed, chances are doctors didn't check you for a silent killer -- one that causes some 60,000 potentially preventable deaths a year.

It's called "deep vein thrombosis," when a dangerous blood clot forms deep in the leg muscles. The clot sometimes floats into the lungs, causing sudden death.

Such clots made headlines a few years ago when seemingly healthy people collapsed after long airplane flights. Take an overseas flight today and you'll probably see a video advising walking around or at least wiggling your legs frequently to keep clots at bay.

While that's good advice, it provides a skewed vision of the clots: Most actually occur when people are hospitalized for surgery, trauma or some other reason. Worse, although simple steps can prevent blood clots in hospitalized patients, troubling new research suggests too many physicians either don't know to check for the risk or they forget.

Now a group of doctors and federal health officials are trying to raise public awareness of DVT, so more physicians will check for it -- and so people at risk can take steps to protect themselves, whether they're entering the hospital or taking a long trip.

"There are so many preventable deaths," laments Dr. Samuel Goldhaber of Harvard Medical School. "It's become a crisis."

Goldhaber is conducting the largest study ever done on who gets DVT and why, using a registry of 5,000 DVT patients from 180 hospitals. Findings so far are "quite shocking," he said. More than half of people who developed DVT while hospitalized for other reasons never got preventative treatment.

There aren't precise counts, but officials estimate up to 2 million Americans suffer DVT each year. In as many as 600,000, the clot moves to the lungs, called a pulmonary embolism. Anywhere from 60,000 to 100,000 of them die. Survivors often must take the blood-thinning drug warfarin for years to prevent recurrence.

Veins have a hard job fighting gravity as they push blood from the legs back up toward the heart. Illness, injury or prolonged inactivity can inhibit that action, allowing blood to temporarily pool where clots can form.

Risk factors include:

Hospitalization for a serious illness or surgery.

Immobility from paralysis or long-distance travel.

Obesity.

Excess estrogen during pregnancy or from birth control pills or hormone therapy.

Smoking.

An inherited tendency for sticky, clot-prone blood.

Being over age 40.

Chronic diseases such as high blood pressure or cancer.