Reducing CT-PA Ordering for Suspected Pulmonary Embolism

The pulmonary embolism rule-out criteria (PERC) (see table) and Wells score (see table) coupled with d-dimer testing (Wells/d-dimer) are validated decision rules that safely eliminate the need for computed tomography pulmonary angiography (CT-PA) in patients with suspected PE. Researchers prospectively evaluated use of these rules in 152 patients who had CT-PA ordered as part of their evaluation for suspected PE. The primary outcome was diagnosis of PE on CT-PA or at 90-day follow-up.

Of the 14 patients who met all 8 PERC criteria, none had PE. Of the 21 patients with low-risk Wells scores and negative d-dimer results, none had PE. Use of these rules would have safely decreased the use of CT-PA by 9% (PERC) or 14% (Wells/d-dimer).