Check the 8 PERC criteria to rule out PE without a D-dimer when pretest probability is low.
Apply PERC only when pretest probability of PE is low (Wells or Geneva). It does not apply at intermediate or high pretest probability.
PERC (Pulmonary Embolism Rule-out Criteria) was developed by Kline in 2004 to exclude PE without laboratory tests. The rule applies only when pretest probability by Wells or Geneva is low; at intermediate or high probability PERC is invalid. Eight binary criteria: age <50, HR <100, SpO2 ≥95% on room air, no haemoptysis, no estrogen use, no surgery or trauma within 4 weeks, no prior VTE, no unilateral leg swelling. If all eight answer "no", PE is excluded without D-dimer with a missed-PE rate below 2%. SEMI (Spanish Society of Internal Medicine) incorporates PERC into the SEC algorithm for PE workup in the ED.
Kline JA, Mitchell AM, Kabrhel C, Richman PB, Courtney DM. J Thromb Haemost 2004;2(8):1247-55
Formula version: kline-2004-v1