The PERC score can be used as a screening tool in patients with a low clinical likelihood of pulmonary embolism – to assess if there is a need for further work-up, or to exclude a diagnosis of PE.
- PERC stands for Pulmonary Embolism Rule-out Criteria
A score of ≥1 (i.e. any factor is positive) indicates a positive PERC score and PE cannot be excluded on the basis of PERC score alone in these patients.
The test it typically applied in the emergency department setting for patients in whom PE is an unlikely differential. It may be considered as a adjunct, rather than an alternative to the Well’s score.
| Age > 50 |
| HR > 100 |
| O2 sats on room air <95% |
| Unilateral leg swelling |
| Use of oestrogen containing medication (e.g. COCP) |
| Haemoptysis |
| Recent trauma or surgery (within the last 4 weeks) |
| Previous PE or DVT |