Fat embolism in pediatric patients: an autopsy evaluation of incidence and etiology

Little is known about the incidence and etiology of fat embolism in pediatric patients. We sought to determine the incidence, time course, and associated factors of pulmonary fat embolism (PFE), cerebral fat embolism (CFE), and kidney fat embolism (KFE) in trauma and nontrauma pediatric patients at the time of autopsy.

Retrospectively, a convenience sample of consecutive pediatric patients (age, ≤10 years) who had undergone autopsy between 2008 and 2012 were evaluated for fat embolism. Patients who had no documented cause of death or who were hospital births and died during the same hospitalization were excluded. Formalin-fixed paraffin sections were reviewed by a forensic pathologist for evidence of fat embolism and nuclear elements. Autopsy reports were used to determine cause of death, injuries, resuscitative efforts taken, sex, height, weight, and age.

Sixty-seven decedents were evaluated. The median age was 2.0 years (interquartile range, 0.75-4), median body mass index (BMI) was 18.0 kg/m(2) (interquartile range, 15.7-19.0 kg/m(2)), and 55% of the patients were male. Pulmonary fat embolism, CFE, and KFE were present in 30%, 15%, and 3% of all patients, respectively. The incidence of PFE was not significantly different by cause of death (trauma 33%, drowning 36%, burn 14%, medical 28%). Patients with PFE but not CFE had significantly higher age, height, weight, and BMI. Half of the PFE and 57% of the CFE occurred in patients who lived less than 1 hour after beginning of resuscitation. Seventy-one percent of patients with CFE did not have a patent foramen ovale. Multivariate regression revealed an increased odds ratio of PFE based on BMI (1.244 [95% confidence interval, 1.043-1.484], P = .015). None of the samples evaluated demonstrated nuclear elements.

Pulmonary fat embolism, CFE, and KFE are common in pediatric trauma and medical deaths. Body mass index is independently associated with the development of PFE. Absence of nuclear elements suggests that fat embolism did not originate from intramedullary fat.