PERC Rule for Pulmonary Embolism

Use the PERC rule to rule out PE if no criteria are present and pre-test probability is <15%.

The global unit selector only affects unanswered questions
2.Heart Rate?
3.O₂ Sat on Room Air?
4.Prior History of Venous Thromboembolism?
5.Surgery or Trauma in Last 4 Weeks?
7.Exogenous Estrogen?
8.Unilateral Leg Swelling?
Created by

1. Age?

Created by
0/8 completed

About this Calculator

The PERC rule is used to rule out pulmonary embolism in those patients where the clinical gestalt is that they are low risk (ie <15% risk of pulmonary embolism).

Pulmonary embolism can be ruled out if none of the following features are identified:

  • Age ≥50 years
  • Heart rate ≥100 bpm
  • Oxygen saturation <95%
  • Hemoptysis
  • Estrogen use
  • Prior DVT or PE
  • Unilateral leg swelling
  • Surgery/trauma within the previous four weeks

In patients with a low pre-test probability of PE who meet any of these criteria, further testing could be considered to more definitely rule out pulmonary embolism.


Kline JA et al.

Prospective multicenter evaluation of the pulmonary embolism rule-out criteria.

Journal of Thrombosis and Haemostasis: JTH 2008, 6 (5): 772-80

Legal Notices and Disclaimer

© 2020 QxMD Software Inc., all rights reserved. No part of this service may be reproduced in any way without express written consent of QxMD. This information should not be used for the diagnosis or treatment of any health problem or disease. This information is not intended to replace clinical judgment or guide individual patient care in any manner. Click here for full notice and disclaimer.