Using a diagnostic algorithm of revised Geneva, D-dimer, leg ultrasound, CTPA (and V/Q if inconclusive) safely ruled out PE in pregnant women.
In this retrospective review, age-adjusted, clinical probability-adjusted, and standard D-dimer approaches had similar NPVs (99.7%, 99.1%, 100% respectively). Clinical probability-adjusted D-dimer has potential to exclude PE in more patients without imaging, but use caution before applying this to practice until prospectively validated.
If clinical gestalt for PE is low, use PERC to rule out PE. If not ruled out, use a validated tool to determine pretest probability of PE: Wells, Revised Geneva, or simplified versions of either score. If non-high or "unlikely" pretest probability, order D-dimer, adjusting for age (<500 or <age x 10). If D-dimer is negative, PE is ruled out. If positive, order CT pulmonary angiogram.