A retrospective analysis of the combined use of PERC rule and Wells score to exclude pulmonary embolism in the Emergency Department.
BACKGROUND
The pulmonary embolism rule-out criteria (PERC) rule is an eight-factor decision rule to support the decision not to order a diagnostic test when the gestalt-based clinical suspicion on pulmonary embolism (PE) is low.


METHODS
In a retrospective cohort study, we determined the accuracy of a negative PERC (0) in patients with a low Wells score (<2) to rule-out PE, and compared this to the accuracy of the default algorithm used in our hospital (a low Wells score in combination with a negative D-dimer).


RESULTS
During the study period, 377 patients with a Wells score <2 were included. CT pulmonary angiography (CTPA) was performed in 86 patients, and V/Q scintigraphy in one patient. PE was diagnosed in 18 patients. 78 patients (21%) had a negative PERC score. When further diagnostic studies would have been omitted in these patients, two (subsegmental) PEs would have been missed, resulting in a sensitivity of 89% (64%-98%) and a negative likelihood ratio (LR-) of 0.52 (0.14-1.97). The default algorithm missed one (subsegmental) PE, resulting in a sensitivity of 95% (71%-99%) and an LR- of 0.25 (0.04-1.73).


CONCLUSIONS
The combination of a Wells score <2 and a PERC rule of 0 had a suboptimal sensitivity for excluding PE in our sample of patients presenting in the ED. Further studies are warranted to test this algorithm in larger populations.
Department of Emergency Medicine, Medical Centre Leeuwarden, Leeuwarden, The Netherlands.
Jmg
J
Theunissen
Department of Emergency Medicine, Medical Centre Leeuwarden, Leeuwarden, The Netherlands.
C
C
Scholing
Department of Emergency Medicine, Medical Centre Leeuwarden, Leeuwarden, The Netherlands.
W E
WE
van Hasselt
Department of Pulmonology, Medical Centre Leeuwarden, Leeuwarden, The Netherlands.
J
J
van der Maten
Department of Emergency Medicine, Medical Centre Leeuwarden, Leeuwarden, The Netherlands.
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http://orcid.org/0000-0002-1462-6130
E
Ter Avest
D000368:Aged; D000465:Algorithms; D000792:Angiography; D003661:Decision Support Techniques; D003937:Diagnosis, Differential; D004636:Emergency Service, Hospital / Q000458:organization & administration*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000175:diagnosis*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
pulmonary embolism; thrombo-embolic disease, diagnosis