Fat embolism in orthopedic surgery: role of bone marrow fatty acid

Imaging of Lipids in Native Human Bone Sections Using TOF-Secondary Ion Mass Spectrometry, Atmospheric Pressure Scanning Microprobe Matrix-Assisted Laser Desorption/Ionization Orbitrap Mass Spectrometry, and Orbitrap-Secondary Ion Mass Spectrometry

A method is described for high-resolution label-free molecular imaging of human bone tissue. To preserve the lipid content and the heterogeneous structure of osseous tissue, 4 μm thick human bone sections were prepared via cryoembedding and tape-assisted cryosectioning, circumventing the application of organic solvents and a decalcification step. A protocol for comparative mass spectrometry imaging (MSI) on the same section was established for initial analysis with time-of-flight secondary ion mass spectrometry (TOF-SIMS) at a lateral resolution of 10 μm to <500 nm, followed by atmospheric pressure scanning microprobe matrix-assisted laser desorption/ionization (AP-SMALDI) Orbitrap MSI at a lateral resolution of 10 μm. This procedure ultimately enabled MSI of lipids, providing the lateral localization of major lipid classes such as glycero-, glycerophospho-, and sphingolipids. Additionally, the applicability of the recently emerged Orbitrap-TOF-SIMS hybrid system was exemplarily examined and compared to the before-mentioned MSI methods.

Fat embolism syndrome: an autopsy-proven case involving a patient on dialysis and systemic scleroderma

A 66-year-old woman receiving continuous ambulatory peritoneal dialysis developed acute respiratory distress 12 hours after a fall. Blood gas analysis revealed hypoxia (PaO2 67.7 torr) and metabolic acidosis with an increased anion gap, consistent with lactic acidosis (lactate, 86.5 mg/dL; normal range, 4.0-16.0). Magnetic resonance imaging showed a lumbar vertebral body fracture. On the fourth hospital day, the patient died of multiorgan failure and disseminated intravascular coagulation. Postmortem studies revealed fat emboli in the systemic circulation, ie, fat embolism syndrome. Diagnosing fat embolism syndrome can be difficult in patients on dialysis or in those with collagen vascular or pulmonary diseases.

Two variants of fat embolism syndrome evolving in a young patient with multiple fractures

Fat embolism syndrome (FES) is a continuum of fat emboli. Variants of FES: acute fulminant form and classic FES are postulated to represent two different pathomechanisms. Acute fulminant FES occurs during the first 24 h. It is attributed to massive mechanical blockage pulmonary vasculature by the fat emboli. The classic FES typically has a latency period of 24-36 h manifestation of respiratory failure and other signs of fat embolism. Progression of asymptomatic fat embolism with FES frequently represents inadequate treatment of hypovolaemic shock. We present a rare case of two variants of FES evolving in a patient with multiple fractures to emphasis the importance of adequate and appropriate treatment of shock in preventing the development of FES. Since supportive therapy which is a ventilatory support remains as the treatment of FES, it is appropriate to treat FES in the intensive care unit setting.