Whole-body CT scans can confirm immediately whether severe trauma patients have certain injuries, but these tests could miss other serious problems if performed too early, a new study indicates.

The German researchers concluded that most emergency-room CT scans are done too soon, and could miss significant internal injuries. For the best results, the study authors concluded, emergency-room doctors should wait at least 30 minutes before ordering CT scans.

“The pan-scan performs best 30 minutes after admission, because the sensitivity of the scan increases after this interval,” study author Dr. Dirk Stengel, of the Center for Clinical Research at Unfallkrankenhaus Berlin and Ernst Moritz Arndt University Medical Center, said in a journal news release. “The transfusion of fluids, blood, plasma and emergency interventions to stabilize circulation will restore organ perfusion, and make bleedings and hematomas visible on CT scans.”

The researchers examined data on 982 patients who received treatment at a trauma center in Berlin between July 2006 and November 2008.

The study, appearing March 5 in the Canadian Medical Association Journal, found nearly 37 percent of the patients were diagnosed with multiple trauma and about 8 percent of the scans ordered were unnecessary. The researchers also found that, in more than 6 percent of the patients, the scans missed injuries that required surgery or monitoring in the intensive care unit.

“We found that single-pass whole-body [CT] is very effective or specific at determining where there is injured tissue but is variable in excluding injuries in patients with suspected blunt trauma,” Stengel said. “Screening tests in trauma are intended to immediately detect life-threatening injuries. Given this premise, high specificity — meaning that a positive test result shows injury — makes pan-scanning a valuable tool.”

Pan-scanning refers to a CT scan that includes the head, neck, chest and abdomen.

The researchers added that negative test results should be confirmed with clinical exams or additional tests to rule out false-negative results.

More information

The U.S. National Institutes of Health provides more information on CT scans.

– Mary Elizabeth Dallas

SOURCE: Canadian Medical Association Journal, news release, March 5, 2012

Last Updated: March 05, 2012