Patients with PE present with a wide spectrum of risk. Some patients can be managed safely as outpatients while others require urgent consideration of re-perfusion therapies. The PESI assists to risk stratify patients with PE.
PESI– Pulmonary Embolism Severity Index
The PESI is a clinical prediction rule that was developed from a large Pennsylvania database in order to assign 30 day mortality risk. Based on scores derived from patient demographics, co-morbid illnesses, and presenting clinical characteristics, patients were assigned to 1 of 5 groups of PE severity and mortality risk. It was prospectively validated in a group of patients from Switzerland and France.
Link to PESI paper.
The Simplified PESI was developed in order to provide a more user friendly version prediction model, but maintain a similar degree of accuracy provided by the original PESI. Authors derived the rule from a Spanish cohort and compared it to the original PESI, then externally validated the model with data from the international venous thromboembolism registry RIETE. The Simplified PESI uses 6 variables to determine risk, which down from a whopping 11 in the original PESI, probably saving the practitioner 30 seconds of time.
The ESC guidelines recommend risk stratification of patients presenting with pulmonary embolism. Obviously, patients presenting with shock or hypotension are HIGH risk and immediate thrombolysis should be offered if not contraindicated and the diagnosis of PE has been reasonably determined. The guidelines recommend that patients WITHOUT hypotension OR shock should receive PE risk assessment with the PESI or simplified PESI to determine which patients are low risk VS. intermediate risk. Those patients who are INTERMEDIATE risk (PESI class III to V, or simplified PESI ≥1) should have further risk determination with ECHO (if possible) and biomarkers. If RV dysfunction/dilation is present on ECHO (or CT RV dilation is observed) and biomarkers are elevated, the ESC recommends in addition to immediate anticoagulation, one should provide high level monitoring and consideration for thrombolysis or other pulmonary arterial re-perfusion therapies.
Link to 2014 European Society of Cardiology Pulmonary Embolism Guidelines