May 25, 2009

ERs may not use lung blood clot guidelines

Emergency room physicians may not be following clinical guidelines for diagnosing patients with possible lung blood clots, U.S. researchers say.

Researchers at the Warren Alpert Medical School of Brown University and Rhode Island Hospital in Providence, R.I., said current accepted clinical practice indicates patients with a low clinical suspicion for pulmonary emboli should undergo a blood test for D-dimer, a protein fragment present in the blood after a clot is degraded, then multi-detector row computed tomography, if positive.

The study, involving 5,344 patients, found, however, that 42 percent of patients had a positive D-dimer exam but did not have a CT scan.

Current protocols suggest that those patients should have had a scan, Dr. Michael T. Corwin, the lead author, said in a statement. "Multi-detector row CT was performed in 7 percent of patients with negative D-dimer results, and the same protocols suggest that those patients should not have undergone a scan.

Anytime a patient gets a CT scan there is a radiation dose. The evaluation of patients with suspected PE should include D-dimer and CT testing in a more standardized fashion so that we can save patients from having unnecessary CT scans.

The D-dimer test should only be used in patients with a relatively low suspicion of having a pulmonary embolus, but if the D-dimer test is positive, then patients should have the CT. If the test is negative then no scanning is needed, Corwin explained.

The finding is published in the American Journal of Roentgenology.