129 - Utility of Wells and PERC Clinical Decision Rules in Pediatric Patients with Pulmonary Embolism

Poster Number: 129
Publication Number: 129.1155

Background: Recent studies suggest that pulmonary embolism (PE) is underdiagnosed in pediatric patients yet has an increased incidence and a potential mortality rate of up to 10%. Wells and PERC clinical algorithms are used in adults to stratify PE risk and minimize the use of CT scans and lab tests.

Objective: The purpose of this study is to evaluate if Wells and PERC criteria can be utilized in pediatric patients to properly stratify the risk of PE with the goal of radiation stewardship.

Design/Methods: This is a retrospective study of patients who underwent PE rule out at one of our tertiary care pediatric hospital locations between 2009 and 2021. Subjects between 0.5 and 20 years old were included. CTA was the diagnostic gold standard with positive CTA indicating cases of PE and negative CTA seen in control patients. Patients were excluded if they had proven septic or tumor emboli. Group comparisons were performed using Student’s t-test or Wilcoxon Rank Sum test for continuous data and Chi-square test or Fisher’s exact test for categorical data. Sensitivity, specificity, PPV, and NPV were provided with their corresponding 95% confidence intervals. Logistic regression was performed to investigate factors associated with PE. All tests were two-sided and p < 0.05 was considered statistically significant.

Results: A total of 279 subjects were included (PE, n=63 and control, n=216). Demographic characteristics are shown in Table 1. All subjects received a Wells score. 184 subjects (including 24 PE patients) were identified as low risk for PE when utilizing a Wells score of less than or equal to 3, with an NPV of 87%, a sensitivity and specificity of 62% and 74%, respectively (Table 2A). PERC rule was then applied to low PE risk patients. PERC rule showed an NPV of 92.5%, with sensitivity and specificity of 75% and 46%, respectively, with a negative likelihood ratio of 0.54 (Table 2B). Additionally, 10% of PE patients were ruled out clinically using the PERC rule. Changing the Wells low risk cut off score to decrease the number of those requiring labs and imaging did not result in test performance improvements.

Conclusion(s): This study demonstrates that adult risk stratification methods for PE cannot safely be used in children and highlights the importance of further studies to establish a clinical decision tool for pediatric patients.