Written and peer-reviewed by physicians—but use at your own risk. Read our disclaimer.

banner image


Trusted medical answers—in seconds.

Get access to 1,000+ medical articles with instant search
and clinical tools.

Try free for 5 days

Nonthrombotic embolism

Last updated: August 27, 2020

Summarytoggle arrow icon

Embolisms of fat, air, and amniotic fluid are uncommon but potentially life-threatening events caused when these substances enter the circulatory system. Fat emboli mostly originate from the bone marrow in patients with long bone fractures. Air can enter the circulatory system during surgical procedures (mostly neurosurgery), while amniotic fluid emboli occur during delivery. The emboli usually lodge within the pulmonary arteries and cause right ventricular outflow obstruction and circulatory collapse. Clinical features of special embolisms typically include acute onset of hypoxia, hypotension, and neurological symptoms (altered consciousness, seizures, coma). The diagnostic sign of fat embolism is a petechial rash on the upper body (if present), while that of venous air embolism is a mill wheel cardiac murmur. Diagnosis of any type of special embolism is primarily clinical, with arterial blood gas evaluation, ECG, and chest x-ray providing additional evidence. Treatment is mainly supportive and includes oxygenation, mechanical ventilation, and administration of vasopressors, if necessary. Mortality rates of all types of special embolisms are high.


Venous air embolism Arterial air embolism
Clinical features



  1. Baldisseri MR. Amniotic Fluid Embolism Syndrome. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/amniotic-fluid-embolism-syndrome.Last updated: January 26, 2016. Accessed: March 27, 2017.
  2. Moore LE. Amniotic Fluid Embolism. In: Smith CV, Amniotic Fluid Embolism. New York, NY: WebMD. http://emedicine.medscape.com/article/253068. Updated: October 5, 2016. Accessed: March 27, 2017.
  3. Kaur K, Bhardwaj M, Kumar P, Singhal S, Singh T, Hooda S. Amniotic fluid embolism. J Anaesthesiol Clin Pharmacol. 2016; 32 (2): p.153-159. doi: 10.4103/0970-9185.173356 . | Open in Read by QxMD
  4. Levi MM. Disseminated Intravascular Coagulation. In: Nagalla S, Disseminated Intravascular Coagulation. New York, NY: WebMD. http://emedicine.medscape.com/article/199627. Updated: September 29, 2016. Accessed: March 27, 2017.
  5. Gupta A, Reilly CS. Fat embolism. Contin Educ Anaesth Crit Care Pain. 2007; 7 (5): p.148-151. doi: 10.1093/bjaceaccp/mkm027 . | Open in Read by QxMD
  6. George J, George R, Dixit R, Gupta RC, Gupta N. Fat embolism syndrome. Lung India. 2013; 30 (1): p.47-53. doi: 10.4103/0970-2113.106133 . | Open in Read by QxMD
  7. Kosova E, Bergmark B, Piazza G. Fat embolism syndrome. Circulation. 2015; 131 (3): p.317-320. doi: 10.1161/CIRCULATIONAHA.114.010835 . | Open in Read by QxMD
  8. Bulauitan CS. Fat Embolism. In: Lopez Rowe V, Fat Embolism. New York, NY: WebMD. http://emedicine.medscape.com/article/460524. Updated: October 10, 2016. Accessed: March 27, 2017.
  9. Weinhouse GL. Fat Embolism Syndrome. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/fat-embolism-syndrome.Last updated: January 17, 2017. Accessed: March 27, 2017.
  10. O'Dowd LC, Kelley MA. Air Embolism. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/air-embolism.Last updated: July 26, 2016. Accessed: March 27, 2017.
  11. Giraldoa M, Loperab LM, Arangoc M. Venous air embolism in neurosurgery. Rev Colomb Anestesiol. 2015; 43 (Suppl 1): p.40-44. doi: 10.1016/j.rcae.2014.07.002 . | Open in Read by QxMD
  12. Arterial Gas Embolism. http://www.merckmanuals.com/professional/injuries-poisoning/injury-during-diving-or-work-in-compressed-air/arterial-gas-embolism. Updated: October 1, 2015. Accessed: March 27, 2017.
  13. Pulmonary Air Embolism. https://radiopaedia.org/articles/pulmonary-air-embolism. Updated: March 27, 2017. Accessed: March 27, 2017.