Management of Low Suspicion Pulmonary Embolism

Diagnostic Approach

For patients with low suspicion of pulmonary embolism who are PERC-negative, no further imaging is needed as pulmonary embolism is safely excluded 1, 2
When all 8 PERC criteria are met, the risk of pulmonary embolism is lower than the risks of testing, and D-dimer should not be ordered, according to the American College of Physicians 1, 3
The diagnostic pathway for low suspicion pulmonary embolism shows that if PERC-negative, no further testing is required 1, 3

Any D-dimer level above 500 ng/mL in a low pretest probability patient requires imaging, as recommended by the American College of Physicians 1, 3
An elevated D-dimer level should lead to imaging studies, such as CT pulmonary angiography (CTPA), according to the American College of Radiology 1, 3
For patients over 50 years old, an age-adjusted D-dimer cutoff (age × 10 ng/mL) should be used, as suggested by clinical guidelines 4

If D-dimer is elevated, proceed to imaging with CTPA, as recommended by the American College of Radiology 1, 3
If CTPA is contraindicated, a first-line alternative is a ventilation-perfusion (V/Q) scan, according to clinical guidelines 6
A second option for alternative imaging is lower extremity venous ultrasound, which may preclude the need for additional imaging if deep vein thrombosis (DVT) is found 5

The American College of Physicians recommends that if a patient is PERC-positive or has an elevated D-dimer, imaging should be performed to exclude pulmonary embolism 1, 3
The American College of Radiology suggests that CTPA should be ordered immediately if D-dimer is elevated, regardless of age-adjusted cutoffs 1, 3, 4