PERC:
1. age < 50
2. HR < 100
3. SpO2 ? 95%
4. No unilateral leg swelling
5. No hemoptysis
6. No recent trauma or surgery
7. No prior DVT or PE
8. No hormone use
Wells:
1. Clinical signs and symptoms of DVT? (+3)
2. Pulmonary embolism is most likely diagnosis (+3)
3. HR > 100 (+1.5)
4. Immobilization of ?3 days or surgery in previous 4 weeks (+1.5)
5. Previous PE or DVT (+1.5)
6. Hemoptysis (+1)
7. Malignancy with treatment in past 6 months, or palliative (+1)
Score ?4 qualifies to rule out with D dimer [JAMA 295 (2): 172-9]
http://www.mdcalc.com/wells-criteria-for-pulmonary-embolism-pe