PEPPER - Prehospital prediction in pulmonary embolism: The association of the national early warning score with mortality, thrombolysis, and clinical outcomes.

Background: Pulmonary embolism (PE) requires careful risk assessment for informed care decisions. We evaluated the value of the National Early Warning Score (NEWS) in patients with PE when used by emergency medical services at the first patient contact in the prehospital phase.

Methods: In this retrospective observational study, we included adult patients diagnosed with PE in the ED of the General Hospital of Vienna, Medical University of Vienna, between January 2017 and December 2021, that were hospitalized by emergency medical services. We used a regression model to assess the association between prehospital NEWS and a composite primary outcome (30-day all-cause mortality, systemic thrombolysis, or catheter-directed thrombolysis), IMC/ICU admission, and clinical course during the first 24 h. Age, sex, body mass index, and days of symptoms served as covariables.

Main results: Two hundred sixty-one patients (53 % female; mean age 65 years, SD 14.6) with confirmed PE were included. A primary outcome event occurred in 65 (25 %) patients. The prehospital NEWS was associated with the primary outcome (OR 1.23, 95 % CI 1.13-1.33; p < 0.001; adjusted OR 1.21, 95 % CI 1.11-1.32, p < 0.001), the need for admission to the ICU or IMC (OR 1.36, 95 % CI 1.25-1.49; p < 0.001) and mortality (HR: 1.23, 95 % CI 1.11 - 1.38, p < 0.001).

Conclusion: Prehospital NEWS was significantly associated with key clinical outcomes in patients subsequently diagnosed with PE. It may support prehospital decision-making and help guide referral to higher levels of care when appropriate.