Introduction

Pulmonary embolism (PE) in the pediatric population is a relatively rare event. Over the last two decades there has been an increase in the observed occurrence of PE in children (like venous thromboembolism [VTE] more generally), which has been attributed to increased recognition as well as a true increase in incidence stemming from improvements in pediatric care. Concomitant with the increased availability of relatively non-invasive methods of diagnosing PE has been a generally improved survival of previously lethal childhood diseases and an increase in use of central venous catheters (CVC).

The first reported pediatric case appears to have been in 1861, when Loschner described PE in a 9-year-old boy, which followed phlebitis associated with a fracture of the tibia. This case was typical of early case reports of the pre-antibiotic era, when emboli were observed to follow infection, injury to bones and muscle, or deep vein thrombosis. Pediatric PE cases were later reported primarily in autopsy-proven reports. As a result, PE in children was thought to be rare and usually fatal. Autopsy-based studies from the post-antibiotic era later showed an increased prevalence of PE, with a decreased age of affected patients. In addition to infection, other risk factors were established, including congenital heart defect, cancer, and CVC. Pediatric autopsy studies have also shown that fatal, massive pulmonary thromboembolism is a rare event in infants and children. A 50-year autopsy review study reported only eight cases from a total of 17,500 autopsies.