‘Selective Strategy' Recommended for CT Scans in Emergency Department

CINCINNATI―Emergency medicine researchers with the University of Cincinnati (UC) are advocating a new strategy for diagnosing a common but dangerous condition in the emergency room.

Pulmonary embolism, or PE, is a potentially lethal disease in which a blood clot, usually from the legs, travels to the lungs and becomes lodged in a pulmonary artery. But the most common way of testing for PEs, a computed tomography angiography (CTA), comes with so many side effects that researchers in emergency medicine are now looking for ways to reduce use of the test.

In a CTA, a contrast dye is first injected into a vein. As the dye circulates through the body, a CT scan is used to take detailed images of the vessels.

"The use of CTA for blood clots has increased 235 percent between 1991 and 2002,” says Michael Ward, MD, UC emergency medicine operations research fellow. "However, recent literature has shown there are significant risks associated with CTA, including radiation, severe allergic reaction and kidney failure from the contrast dye.

"As more risks are discovered, the development of diagnostic strategies to reduce the use of CTA has become extremely important.”

In a study done June 2010, Ward used existing data to predict costs and results for two models of PE diagnosis. One model tests all patients for PE using a CTA. Another uses compression ultrasound to first test for deep vein thrombosis (DVT), the formation of a blood clot in the leg.

"The diagnosis of a DVT, together with symptoms of PE, almost certainly suggests a PE,” says Ward. "If the test for DVT was positive, the patient was admitted to the hospital for PE and started treatment with anticoagulants. If the test was negative, patients had a CTA performed to evaluate for PE.”

source: University of Cincinnati