Interactive PERC Rule calculator for pulmonary embolism. Requires the calculator gadget. Usage: {{PERC Calculator}}
PERC Rule Calculator
| Criteria
|
No (0)
|
Yes (+1)
|
| Age ≥50 years
|
1
|
|
| Heart rate ≥100 bpm
|
1
|
|
| SpO₂ <95% on room air
|
1
|
|
| Unilateral leg swelling
|
1
|
|
| Hemoptysis
|
1
|
|
| Recent surgery or trauma (within 4 weeks requiring hospitalization)
|
1
|
|
| Prior PE or DVT
|
1
|
|
| Hormone use (oral contraceptives, HRT, or estrogenic hormones)
|
1
|
|
| Positive Criteria
|
/ 8
|
Interpretation
| Score = 0
|
PERC Negative — If pre-test probability is ≤15%, PE is effectively ruled out. No further workup needed (sensitivity 97.4%, NPV 99.5%).
|
| Score ≥ 1
|
PERC Positive — Cannot rule out PE by PERC alone. Consider D-dimer, Wells' score, or CTA based on clinical suspicion.
|
