Hospitalized Patients at High Risk of Vein Clots

But only half get clot-preventing treatments, researchers say.

By Ed Edelson
HealthDay Reporter
Friday, July 13, 2007; 12:00 AM

Copyright © 2007 ScoutNews, LLC. All rights reserved.

FRIDAY, July 13 (HealthDay News) -- A surprisingly large number of hospital patients run the risk of a potentially fatal vein clot, but half of them aren't getting preventive treatment, researchers report.

The clotting condition, called venous thromboembolism (VTE) involves the formation of blood clots in a vein. This can cause serious problems such as blockage of blood vessels in the leg (deep vein thrombosis) or a pulmonary embolism, the blockage of a lung artery. Studies have linked pulmonary embolism to up to 10 percent of in-hospital sudden deaths.

VTE may be a bigger threat to hospitalized Americans than once thought, the new study shows.

"We looked at 38 million discharges in a data base for U.S. hospitals and found that about one of every three people in a hospital bed in the United States arguably should be protected against VTE because they have a risk," said lead researcher Dr. Frederick A. Anderson Jr., director of the Center for Outcomes Research at the University of Massachusetts Medical School.

His team published its findings in the July issue of the American Journal of Hematology.

The report is the first to estimate the number of U.S. hospital patients at risk for VTE, Anderson said. Risk was estimated using criteria set by the American College of Chest Physicians. According to those guidelines, risk factors include a hospital stay of two days or more, the presence of severe medical or surgical conditions, older age and any operation involving general anesthesia.

The study found that, among surgery patients, 24 percent were at high risk of VTE and 17 percent were at very high risk. About half of nonsurgery patients were at some risk for VTE under those criteria.

Patients meeting the criteria should be given preventive treatment, generally an anticoagulant drug such as heparin or Coumadin, when they leave the hospital, Anderson said.

However, he and another researcher, Dr. Samuel Z. Goldhaber of Harvard Medical School, performed another study of 80 selected American hospitals and found that while 50 percent of discharged patients had VTE risk factors, only half received preventive therapy.