The Pulmonary Embolism Rule-Out Criteria rule in a community hospital ED: a retrospective study of its potential utility.

Background: The Pulmonary Embolism Rule-Out Criteria (PERC) rule identifies patients who can be safely discharged from the emergency department (ED) without undergoing laboratory or radiological investigation for possible pulmonary embolism (PE). It was shown to be 99% sensitive in a large validation series. Our objective was to assess the PERC rule's performance in a representative US community hospital.

Methods: A chart review of ED patients receiving computed tomographic scans (CTS) for possible PE during a 4-month study period was performed. The PERC rule was applied to this cohort, and its sensitivity and negative predictive value were determined.

Results: Two hundred thirteen patients underwent chest CTS to "rule out" PE. Forty-eight patients met PERC rule criteria, and all had negative CTS. Of the remaining 165 patients, 18 patients (11%) had scans positive for PE. The overall prevalence of PE was 8.45% (95% CI, 5.22-13.24%). The PERC rule's sensitivity was 100% (95% CI, 78.12-100%), with a negative predictive value of 100% (95% CI, 90.80-100%). Application of the PERC rule at the point-of-care would have reduced CTS by 23%.

Conclusions: In our community hospital, the PERC rule successfully identified ED patients who did not require CTS evaluation for PE. Had the PERC rule been applied, nearly one-quarter of all CTS performed to "rule out PE" could have been avoided.