Official reprint from UpToDate®
www.uptodate.com ©2016 UpToDate®

Fat embolism syndrome

Gerald L Weinhouse, MD
Section Editor
Polly E Parsons, MD
Deputy Editor
Geraldine Finlay, MD


The fat embolism syndrome (FES) remains a diagnostic challenge for clinicians, despite having been initially described in 1873 [1]. Among the reasons that FES is difficult to diagnose is that it can complicate widely disparate clinical conditions and may vary in severity. Management is supportive, with an estimated mortality rate of 5 to 15 percent [2].

The causes, clinical presentation, pathogenesis, diagnosis, treatment, prevention, and outcomes of FES are reviewed here. Other forms of pulmonary embolism are discussed separately. (See "Overview of acute pulmonary embolism in adults" and "Amniotic fluid embolism syndrome" and "Pulmonary tumor embolism and lymphangitic carcinomatosis in adults: Diagnostic evaluation and management" and "Air embolism".)


Fat embolism syndrome (FES) may complicate a wide variety of clinical conditions (table 1). It is most commonly associated with long bone and pelvic fractures, and is more frequent in closed fractures than open fractures. Patients with a single long bone fracture have a 1 to 3 percent chance of developing FES. This increases with the number of fractures. As an example, FES has been noted in up to 33 percent of patients with bilateral femoral fractures [3]. At autopsy, compared to non-trauma patients, a higher proportion of trauma patients have fat embolism (82 versus 63 percent) [4]. In addition, over 85 percent of all patients who had received cardiopulmonary resuscitation had evidence of fat embolism [4].


Fat emboli may be the result of fat globules entering the bloodstream through tissue (usually bone marrow or adipose tissue) that has been disrupted by trauma or, alternatively, via production of the toxic intermediaries of plasma-derived fat (eg, chylomicrons or infused lipids).

"Mechanical" fat embolism — The supposition that fat from disrupted bone marrow or adipose tissue enters torn venules following trauma originated in the early twentieth century [5]. It presumes that fractures of marrow-containing bone have the highest incidence of fat embolism syndrome (FES) and cause the largest volume of fat emboli because the disrupted venules in the marrow are tethered open by their osseous attachments, allowing the marrow contents to easily enter the venous circulation. The notion is supported by the observation that "echogenic material" passes through the right heart during orthopedic and spinal surgery [6,7].


Subscribers log in here

To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information or to purchase a personal subscription, click below on the option that best describes you:
Literature review current through: Nov 2016. | This topic last updated: Wed Jan 06 00:00:00 GMT+00:00 2016.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use ©2016 UpToDate, Inc.
  1. Von Bergmann E. Ein fall todlicher fettembolie. Berl Klin Wchenschr 1873; 10:385. Cited by Sevitt S. Fat Embolism. Butterworth, London, 1962.
  2. Mellor A, Soni N. Fat embolism. Anaesthesia 2001; 56:145.
  3. Johnson MJ, Lucas GL. Fat embolism syndrome. Orthopedics 1996; 19:41.
  4. Eriksson EA, Pellegrini DC, Vanderkolk WE, et al. Incidence of pulmonary fat embolism at autopsy: an undiagnosed epidemic. J Trauma 2011; 71:312.
  5. Warthin, AS. Traumatic lipaemia and fatty embolism. Int Clinics 1913; 23:171.
  6. Pell AC, Hughes D, Keating J, et al. Brief report: fulminating fat embolism syndrome caused by paradoxical embolism through a patent foramen ovale. N Engl J Med 1993; 329:926.
  7. Takahashi S, Kitagawa H, Ishii T. Intraoperative pulmonary embolism during spinal instrumentation surgery. A prospective study using transoesophageal echocardiography. J Bone Joint Surg Br 2003; 85:90.
  8. Sulek CA, Davies LK, Enneking FK, et al. Cerebral microembolism diagnosed by transcranial Doppler during total knee arthroplasty: correlation with transesophageal echocardiography. Anesthesiology 1999; 91:672.
  9. Nixon JR, Brock-Utne JG. Free fatty acid and arterial oxygen changes following major injury: a correlation between hypoxemia and increased free fatty acid levels. J Trauma 1978; 18:23.
  10. Schnaid E, Lamprey JM, Viljoen MJ, et al. The early biochemical and hormonal profile of patients with long bone fractures at risk of fat embolism syndrome. J Trauma 1987; 27:309.
  11. GLAS WW, GREKIN TD, MUSSELMAN MM. Fat embolism. Am J Surg 1953; 85:363.
  12. Hulman G. Pathogenesis of non-traumatic fat embolism. Lancet 1988; 1:1366.
  13. Carr JB, Hansen ST. Fulminant fat embolism. Orthopedics 1990; 13:258.
  14. King MB, Harmon KR. Unusual forms of pulmonary embolism. Clin Chest Med 1994; 15:561.
  15. Jacobson DM, Terrence CF, Reinmuth OM. The neurologic manifestations of fat embolism. Neurology 1986; 36:847.
  16. Kellogg RG, Fontes RB, Lopes DK. Massive cerebral involvement in fat embolism syndrome and intracranial pressure management. J Neurosurg 2013; 119:1263.
  17. Kaplan RP, Grant JN, Kaufman AJ. Dermatologic features of the fat embolism syndrome. Cutis 1986; 38:52.
  18. Jones JP Jr. Fat embolism, intravascular coagulation, and osteonecrosis. Clin Orthop Relat Res 1993; :294.
  19. Gitin TA, Seidel T, Cera PJ, et al. Pulmonary microvascular fat: the significance? Crit Care Med 1993; 21:673.
  20. Umali, CB, Smith, EH. The chest radiographic examination. In: Intensive Care Medicine, Rippe, JM, Irwin, RS, Alpert, JS, Fink, MP (Eds), Little Brown, Boston 1991. p.596.
  21. Park HM, Ducret RP, Brindley DC. Pulmonary imaging in fat embolism syndrome. Clin Nucl Med 1986; 11:521.
  22. Arakawa H, Kurihara Y, Nakajima Y. Pulmonary fat embolism syndrome: CT findings in six patients. J Comput Assist Tomogr 2000; 24:24.
  23. Malagari K, Economopoulos N, Stoupis C, et al. High-resolution CT findings in mild pulmonary fat embolism. Chest 2003; 123:1196.
  24. Nucifora G, Hysko F, Vit A, Vasciaveo A. Pulmonary fat embolism: common and unusual computed tomography findings. J Comput Assist Tomogr 2007; 31:806.
  25. Takahashi M, Suzuki R, Osakabe Y, et al. Magnetic resonance imaging findings in cerebral fat embolism: correlation with clinical manifestations. J Trauma 1999; 46:324.
  26. Gurd, AR. Fat embolism: An aid to diagnosis. J Bone Joint Surg 1970; 52B:732.
  27. Godeau B, Schaeffer A, Bachir D, et al. Bronchoalveolar lavage in adult sickle cell patients with acute chest syndrome: value for diagnostic assessment of fat embolism. Am J Respir Crit Care Med 1996; 153:1691.
  28. Vichinsky E, Williams R, Das M, et al. Pulmonary fat embolism: a distinct cause of severe acute chest syndrome in sickle cell anemia. Blood 1994; 83:3107.
  29. Chastre J, Fagon JY, Soler P, et al. Bronchoalveolar lavage for rapid diagnosis of the fat embolism syndrome in trauma patients. Ann Intern Med 1990; 113:583.
  30. Karagiorga G, Nakos G, Galiatsou E, Lekka ME. Biochemical parameters of bronchoalveolar lavage fluid in fat embolism. Intensive Care Med 2006; 32:116.
  31. Riska EB, Myllynen P. Fat embolism in patients with multiple injuries. J Trauma 1982; 22:891.
  32. Pitto RP, Schramm M, Hohmann D, Kössler M. Relevance of the drainage along the linea aspera for the reduction of fat embolism during cemented total hip arthroplasty. A prospective, randomized clinical trial. Arch Orthop Trauma Surg 1999; 119:146.
  33. Pitto RP, Koessler M, Kuehle JW. Comparison of fixation of the femoral component without cement and fixation with use of a bone-vacuum cementing technique for the prevention of fat embolism during total hip arthroplasty. A prospective, randomized clinical trial. J Bone Joint Surg Am 1999; 81:831.
  34. Kröpfl A, Davies J, Berger U, et al. Intramedullary pressure and bone marrow fat extravasation in reamed and unreamed femoral nailing. J Orthop Res 1999; 17:261.
  35. Kim YH, Oh SW, Kim JS. Prevalence of fat embolism following bilateral simultaneous and unilateral total hip arthroplasty performed with or without cement : a prospective, randomized clinical study. J Bone Joint Surg Am 2002; 84-A:1372.
  36. Pitto RP, Hamer H, Fabiani R, et al. Prophylaxis against fat and bone-marrow embolism during total hip arthroplasty reduces the incidence of postoperative deep-vein thrombosis: a controlled, randomized clinical trial. J Bone Joint Surg Am 2002; 84-A:39.
  37. Alho A, Saikku K, Eerola P, et al. Corticosteroids in patients with a high risk of fat embolism syndrome. Surg Gynecol Obstet 1978; 147:358.
  38. Lindeque BG, Schoeman HS, Dommisse GF, et al. Fat embolism and the fat embolism syndrome. A double-blind therapeutic study. J Bone Joint Surg Br 1987; 69:128.
  39. Kallenbach J, Lewis M, Zaltzman M, et al. 'Low-dose' corticosteroid prophylaxis against fat embolism. J Trauma 1987; 27:1173.
  40. Schonfeld SA, Ploysongsang Y, DiLisio R, et al. Fat embolism prophylaxis with corticosteroids. A prospective study in high-risk patients. Ann Intern Med 1983; 99:438.
  41. Bederman SS, Bhandari M, McKee MD, Schemitsch EH. Do corticosteroids reduce the risk of fat embolism syndrome in patients with long-bone fractures? A meta-analysis. Can J Surg 2009; 52:386.
  42. Kubota T, Ebina T, Tonosaki M, et al. Rapid improvement of respiratory symptoms associated with fat embolism by high-dose methylpredonisolone: a case report. J Anesth 2003; 17:186.
  43. Fischer JE, Turner RH, Herndon JH, Riseborough EJ. Massive steroid therapy in severe fat embolism. Surg Gynecol Obstet 1971; 132:667.
  44. Ashbaugh DG, Petty TL. The use of corticosteroids in the treatment of respiratory failure associated with massive fat embolism. Surg Gynecol Obstet 1966; 123:493.
  45. Fulde GW, Harrison P. Fat embolism--a review. Arch Emerg Med 1991; 8:233.
  46. Kim CH, Chung DH, Yoo CG, et al. A case of acute pneumonitis induced by injection of silicone for colpoplasty. Respiration 2003; 70:104.
  47. Lai YF, Chao TY, Wong SL. Acute pneumonitis after subcutaneous injections of silicone for augmentation mammaplasty. Chest 1994; 106:1152.
  48. Chastre J, Brun P, Soler P, et al. Acute and latent pneumonitis after subcutaneous injections of silicone in transsexual men. Am Rev Respir Dis 1987; 135:236.
  49. Chung KY, Kim SH, Kwon IH, et al. Clinicopathologic review of pulmonary silicone embolism with special emphasis on the resultant histologic diversity in the lung--a review of five cases. Yonsei Med J 2002; 43:152.
  50. Schmid A, Tzur A, Leshko L, Krieger BP. Silicone embolism syndrome: a case report, review of the literature, and comparison with fat embolism syndrome. Chest 2005; 127:2276.