PERC

 Q: What is PERC rule for Pulmonary embolism? 

 Answer: The PERC rule stands for Pulmonary Embolism Rule-out Criteria. There are eight components of it and if patient meets all of them, the PE can be ruled out with good confidence. It is clinically described as a low clinical probability of PE - and further testing can be avoided. 

• Age less than 50 
• Heart rate less than 100 
• Saturation more than/equal to 95% 
• No hemoptysis 
• No estrogen use 
• No prior DVT/PE 
• No unilateral leg swelling 
• No hospitalization in prior 4 weeks due to surgery/trauma

Said that PERC is valid for acute presentations like in ED, and should not be used for patients who have prolong hospitalization.

#pulmonary

References:

1. Kline JA, Courtney DM, Kabrhel C, et al. Prospective multicenter evaluation of the pulmonary embolism rule-out criteria. J Thromb Haemost 2008; 6:772. 

2. Raja AS, Greenberg JO, Qaseem A, et al. Evaluation of Patients With Suspected Acute Pulmonary Embolism: Best Practice Advice From the Clinical Guidelines Committee of the American College of Physicians. Ann Intern Med 2015; 163:701. 

3. Hugli O, Righini M, Le Gal G, et al. The pulmonary embolism rule-out criteria (PERC) rule does not safely exclude pulmonary embolism. J Thromb Haemost 2011; 9:300. 

4. Singh B, Mommer SK, Erwin PJ, et al. Pulmonary embolism rule-out criteria (PERC) in pulmonary embolism--revisited: a systematic review and meta-analysis. Emerg Med J 2013; 30:701. 

5. Freund Y, Cachanado M, Aubry A, et al. Effect of the Pulmonary Embolism Rule-Out Criteria on Subsequent Thromboembolic Events Among Low-Risk Emergency Department Patients: The PROPER Randomized Clinical Trial. JAMA 2018; 319:559.