Pulmonary embolism in children

The diagnosis of pulmonary embolism (PE) is seldom considered in the pediatric patient; however, pulmonary embolic phenomenon occur with a greater frequency than is generally recognized. Reports of all autopsies performed at the University of Michigan during the 25-yr period 1955 through 1979 were reviewed. All cases of pulmonary thromboembolism in infants and children ranging in age from 0 to 19 yr were studied; patients with emboli from fat or tumors and patients with primary pulmonary artery thrombosis were excluded. The records of 116 children with PE were evaluated. The sex distribution was equal and the average age was 8.0 yr. Age itself was not an independent risk factor for the development of PE. The primary disease processes of shunted hydrocephalus (15.2%), accidental trauma (8.4%), heart disease (4.5%), infection (4.4%), neoplasia (4.0%), and general medical illness (1.8%) were identified as significant risk factors for the development of pulmonary emboli. In the group with neoplasia, children with solid tumors (6.7%) were at an increased risk over the lymphomaleukemia group (2.6%) for the development of emboli. Children who had operation exclusive of the risk factors noted above (7.2%) were at an increased risk when compared to the nonoperative medical group (1.7%). Other risk factors including immobility, central venous catheterization, pre-existing hematologic disorders, and secondary infection were frequently seen. These factors, however, were not able to be studied epidemiologically. Venous thromboses were found in 40% of those children who had pulmonary emboli at the time of autopsy. Iliofemoral venous thrombosis was infrequently seen. The PE was deemed to be clinically important in 30% of the total series. In patients with clinically significant PE, only 50% had documented signs and symptoms of embolization and an antemortem diagnosis was considered in only one-third of these symptomatic patients. The total incidence of PE did not change over the 25-yr period, nor were there any significant trends in the associated risk factors. This study supports the concept that PE occurs in children with a greater frequency than is commonly recognized. Signs and symptoms of clinically significant pulmonary emboli occur in only 50% of the patients and even when the event presents clinically, it is an underdiagnosed entity. A heightened index of suspicion for PE in children is warranted.