EBQ:PERC Rule Validation

Under Review Journal Club Article

Kline J.A. et al. "Prospective multicenter evaluation of the pulmonary embolism rule-out criteria". Journal of Thrombosis and Haemostasis. 2008. 6(5):772–780.
PubMed Full text PDF

Clinical Question

Can risk stratification to low risk for pulmonary embolism (PE) in combination with a negative Pulmonary Embolism Rule Out Criteria (PERC) score reduce the probability of PE to less than 2%?

Conclusion

The combination of gestalt estimate of low suspicion for PE and PERC(-) reduces the probability of VTE to below 2% in about 20% of outpatients with suspected PE.

Population Studied

Exclusion Criteria

.

Discussion

PERC Rule:

1. Is the patient older than 49 years of age?
2. Is the pulse rate above 99 beats min)1?
3. Is the pulse oximetry reading <95% while the patient breathes room air?
4. Is there a present history of hemoptysis?
5. Is the patient taking exogenous estrogen?
6. Does the patient have a prior diagnosis of venous thromboembolism (VTE)?
7. Has the patient had recent surgery or trauma? (Requiring endotracheal intubation or hospitalization in the previous 4 weeks.)
8. Does the patient have unilateral leg swelling? (Visual observation of asymmetry of the calves.)

CME

1 PERC stands for pulmonary embolism rule out criteria. In this study of 8138 patients, 1666 were found to be low clinical suspicion and PERC negative. The conclusion of the study was

	patients with a medium probablity of PE and PERC negative can be discharged home
	patients with a high probability of PE and PERC positive should be anticoagulated
	patients with low probability of PE and PERC negative will have a probability of less than 2% of VTE
	PERC failed to be predictive of PE in this cohort of patients

2 PERC consists of the following rules:

	Age < 50, HR < 100, O2 sat >95%, No history of DVT/PE, No recent trauma or surgery, no hemoptysis, no exogenous estrogen, no unilateral leg swelling
	Age < 65, HR < 100, O2 sat >95%, No history of DVT/PE, No recent trauma or surgery, no hemoptysis, no exogenous estrogen, no unilateral leg swelling
	Age < 50, HR < 100, O2 sat >90%, No history of DVT/PE, No recent trauma or surgery, no hemoptysis, no exogenous estrogen, no unilateral leg swelling
	Age < 50, HR < 60, O2 sat >95%, No history of DVT/PE, No recent trauma or surgery, no hemoptysis, no exogenous estrogen, no unilateral leg swelling

3 The utility of the PERC rule is greatest in which of the following patients suspected of a pulmonary embolism?

	High pretest probability
	Intermediate pretest probability
	Low pretest probability

Related Publications

• ACEP clinical policy; Ann Emerg Med 2011; 57:628-650.