Background: Fat embolism syndrome (FES) is a rare syndrome resulting from a fat embolism, which is defined by the presence of fat globules in the pulmonary microcirculation; it is associated with a wide range of symptoms.
Research question: What are the specific unknown risk factors for FES after we have controlled for basic characteristics and patient's severity?
Study design and methods: This was a nested case-control study that used the Japan Trauma Data Bank database from 2004 and 2017. We included patients with FES and identified patients without FES as control subjects using a propensity score matching. The primary outcome was the presence of FES during a hospital stay.
Results: There were 209 (0.1%) patients with FES after trauma; they were compared with 2,090 matched patients from 168,835 candidates for this study. Patients with FES had long bone and open fractures in their extremities more frequently than those without FES. Regarding treatments, patients with FES received bone reduction and fixation more than those without FES. Among patients who received bone reduction and fixation, time to operation was not different between the groups (P = .63). The overall in-hospital mortality rate was 5.8% in patients with FES and 3.4% in those without FES (P = .11). Conditional logistic regression models to identify risk factors associated with FES shows long bone and open fractures in extremities injury were associated with FES. Primary bone reduction and fixation was not associated independently with FES (OR, 1.80; 95% CI, 0.92-3.54), but delay time to the operation was associated with FES (OR, 2.21; 95% CI, 1.16-4.23).
Interpretation: Long bone and open fractures in injuries to the extremities were associated with FES. Although bone reduction and fixation were not associated with FES, delay time to the operation was associated with FES.
Keywords: extremities; fat embolism syndrome; trauma.
Copyright © 2020 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.