The paper
Kline et al
Journal of Thrombosis and Haemostasis 2008
Prospective Multicenter Evaluation of the
Pulmonary Embolism Rule Out Criteria
As a background
2004 Kline PERC derivation paper ‘Clinical
criteria to prevent unnecessary diagnostic
testing in the Emergency Department; patients
with suspected pulmonary embolism’
PERC rule
• Decision tool to support the clinician deciding
not to investigate a patient for a suspected PE
– Providing that the clinician had a low clinical
suspicion of PE i.e. < 15%
The PERC rule
Must in addition have all of the following 8 points
Less than 50 years old
Pulse rate < 100
Pulse oximetry reading > 94% whilst breathing room air
No history of haemoptysis
Not taking exogenous oestrogen
No previous history of VTE
No history of recent surgery or trauma (requiring
endotracheal intubation or hospitalization in the past 4
weeks)
Visually not evidence of unilateral calf swelling
• Patients enrolled once an objective test was
ordered to investigate a PE - written by or
under the supervision of a board certified
emergency physician
– CTPA, VQ or a d-dimer
Data collected
• Patients followed up for 45 days
– Telephone, mail, primary care physician, social
security death index
• Used the presence of VTE (DVT or PE) in the
next 45 days as a diagnosis of VTE
Results
• Enrolled 8138 from eligible 12213
• 53% patients had chest pain, 33% dyspnoea
• Prevelance of disease in the entire group 5.9%
had PE within 45 days
Results
• In 1666 patients (20% of cohort) were
– Gestalt of PE low
– PERC negative
• Of these patients
– 1% had a VTE or died within 45 days
(upper 95% CI of 1.6%)
References
• Kline, J A et al. “Prospective multicenter
evaluation of the pulmonary embolism ruleout criteria.” Journal of thrombosis and
haemostasis JTH 6.5 (2008) : 772-780