By Jason West. MD | February 11th, 2014
"Kline et al developed a clinical decision tool based on parameters that could be obtained from a brief initial assessment to reasonably exclude the diagnosis of pulmonary embolism (PE) without the use of D-dimer in order to prevent unnecessary cost and the use of medical resources [1]. Many of us have used the Pulmonary Embolism Rule-out Criteria (PERC) rule by now, but we should be clear on what it includes. Are we using it appropriately?"TEACHING POINTS
- Gestalt or some form of risk stratification should be employed first before using the PERC rule, which is reserved for low pretest probability cases.
- Because the negative LR of the PERC rule is 0.17, this allows you to have a maximum pretest probability of about 10.7% to apply the PERC rule to risk stratify your patient down to the standard risk of 2% (see below).
- The maximum suggested prevalence for PE in order to use the PERC rule is 7%.
- Pleuritic chest pain may increase the likelihood of PE more than some variables within existing decision rules.
- The PERC rule should not be used in isolation to rule out PE in pregnant or postpartum patients.
- The PERC rule includes hypoxemia or tachycardia at any point during the evaluation.
http://academiclifeinem.com/when-perc-rule-fails/