Clinical variables that increase the probability of pulmonary embolism diagnosis in symptomatic children

Background: Pulmonary embolism (PE) in children carries a significant morbidity and mortality. We examined previously described factors in 2 cohorts of children tested for PE and identified novel factors. Methods: We combined data from 2 retrospective cohorts. Patients up to age 21 years were included who underwent imaging or D-dimer testing for PE, with positive radiologic testing being the gold standard. Combined predictor variables were examined by univariate analysis and then forward stepwise multivariable logistic regression. Results: The combined data set yielded 1103 patients with 42 unique predictor variables, and 93 PE-positive patients (8.4%), with a median age of 16 years. Univariate analysis retained 17 variables, and multivariable logistic regression found 9 significant variables with increased probability of PE diagnosis: age-adjusted tachycardia, tachypnea, hypoxia, unilateral limb swelling, trauma/surgery requiring hospitalization in previous 4 weeks, prior thromboembolism, cancer, anemia, and leukocytosis. Conclusion: This combined data set of children with suspected PE discovered factors that may contribute to a diagnosis of PE: hypoxia, unilateral limb swelling, trauma/surgery requiring hospitalization in previous 4 weeks, prior thromboembolism, and cancer, age-adjusted tachycardia, tachypnea, anemia, and leukocytosis. Prospective testing is needed to determine which criteria should be used to initiate diagnostic testing for PE in children.