Answer “yes” or “no” to all 8 criteria for a patient who has been determined to be low risk by clinical gestalt (<15%).
Advice
- Sensitivity is lower in high-prevalence settings; a negative result does not exclude PE in moderate- or high-prevalence settings nor in moderate or high-risk patients.
- Many hospitals employ the use of an age-adjusted D-dimer, which can complement the PERC rule.
- This tool is a valuable aid to rule out PE only in patients who are pre-determined to be low risk by physician gestalt.
- When used properly, a negative result can confidently obviate further PE testing.
- It should augment, not supersede, clinical decision-making, so always consider the patient’s full clinical picture.
- Keep in mind its limitations (e.g. not for use in pregnancy or higher-risk cases).
Management
- Consider D-dimer testing in low-risk patients who do not meet all rule-out criteria.
- If the D-dimer is negative and clinical gestalt estimates a pre-test probability <15%, no further testing for PE is required.
- If the D-dimer is positive, perform CT angiography or obtain a V/Q scan if CTA is contraindicated.
- Consider using age-adjusted D-dimer in this protocol.
- In patients with low pretest probability (<15%) who meet all rule-out criteria, PE can be safely excluded.
Critical Actions
- Patients who are low-risk for PE should be evaluated with this tool as it can avoid further testing.
- Patients at moderate-to-high risk for PE should not be evaluated using this tool.
- Patients who are not suspected of having PE do not need to have this rule applied.
- Use caution in high prevalence PE settings.
- Maintain a broad differential in patients presenting with pleuritic complaints.