Fat embolism syndrome

Last updated
Fat embolism syndrome
Other namesFat embolism
Fat embolism.JPEG
Microscopic section of the lungs showing a blood vessel with fibrinoid material and an empty space indicative of the presence of lipid dissolved during the staining process. Haematoxylin and eosin stain
Specialty Orthopedics, traumatology, pulmonology, intensive care medicine
Symptoms Petechial rash, decreased level of consciousness, shortness of breath [1]
Complications Personality changes, seizures, [2] Vessel blockage
Usual onsetWithin 24 hours [1]
Causes Bone fracture, pancreatitis, bone marrow transplant, liposuction [3]
Diagnostic method Based on symptoms [2]
Differential diagnosis Pulmonary embolism, pneumonia [2]
PreventionEarly stabilization of long bone fractures
Treatment Supportive care [4]
Prognosis 10% risk of death [2]
FrequencyRare [4]

Fat embolism syndrome occurs when fat enters the blood stream (fat embolism) and results in symptoms. [1] Symptoms generally begin within a day. [1] This may include a petechial rash, decreased level of consciousness, and shortness of breath. [1] Other symptoms may include fever and decreased urine output. [2] The risk of death is about 10%. [2]

Contents

Fat embolism most commonly occurs as a result of fractures of bones such as the femur or pelvis. [3] [1] Other potential causes include pancreatitis, orthopedic surgery, bone marrow transplant, and liposuction. [3] [2] The underlying mechanism involves widespread inflammation. [3] Diagnosis is based on symptoms. [2]

Treatment is mostly supportive care. [4] This may involve oxygen therapy, intravenous fluids, albumin, and mechanical ventilation. [2] While small amounts of fat commonly occur in the blood after a bone fracture, [3] fat embolism syndrome is rare. [4] The condition was first diagnosed in 1862 by Zenker. [1]

Signs and symptoms

The symptoms of fat embolism syndrome (FES) can start from 12 hours to 3 days after diagnosis of the underlying clinical disease. The three most characteristic features are: respiratory distress, neurological features, and skin petechiae. [5] Respiratory distress (present in 75% of the cases) can vary from mild distress which requires supplemental oxygen to severe distress which requires mechanical ventilation. For neurologic features, those who have FES may become lethargic, restless, with a drop in Glasgow Coma Scale (GCS) due to cerebral oedema rather than cerebral ischaemia. Therefore, neurological signs are not lateralised to one side of the body. In the severe form of cerebral edema, a person may become unresponsive. Petechiae rash usually happens in 50% of the patients. Such skin manifestation is temporary and can disappear within one day. [6] The fat embolism syndrome can be divided into three types: [5]

Causes

Orthopaedic injuries, especially fractures of the long bones, are the most common cause of fat embolism syndrome (FES). The rates of fat embolism in long bone fractures vary from 1% to 30%. The mortality rate of fat-embolism syndrome is approximately 10–20%. [7] However, fat globules have been detected in 67% of those with orthopaedic trauma and can reach as high as 95% if the blood is sampled near the fracture site. As the early operative fixation of long bone fractures became a common practice, the incidence of FES has been reduced to between 0.9% and 11%. [6]

Osteomyelitis OsteomylitisMark.png
Osteomyelitis

Other rare causes of fat embolism syndrome are: [7] [6]

Pathophysiology

Histopathology of a pulmonary artery with fat embolism (seen as multiple empty globular spaces on this H&E stain since its processing dissolves fat). There is a bone marrow fragment in the middle, and multiple single hematopoietic cells in the blood, being evidence of fracture as the source of the embolism. Histopathology of a pulmonary artery with fat embolism and a bone marrow fragment.jpg
Histopathology of a pulmonary artery with fat embolism (seen as multiple empty globular spaces on this H&E stain since its processing dissolves fat). There is a bone marrow fragment in the middle, and multiple single hematopoietic cells in the blood, being evidence of fracture as the source of the embolism.

Once fat emboli enter the blood circulation, they can lodge at various sites of the body, most commonly in the lungs (up to 75% of cases). However, it can also enter the brain, skin, eyes, kidneys, liver, and heart circulation, causing capillary damage, and subsequently cause organ damage in these areas. There are two theories that describe the formation of a fat embolus: [6]

Diagnosis

Separator for hematocrit Separator for hematocrit 0003.JPG
Separator for hematocrit

Fat embolism is presence of fat particles in the micro-circulation of the body. Meanwhile, fat embolism syndrome is the clinical manifestation as the result of fat particles lodging in the body micro-circulation. [6] There are three major diagnostic criteria proposed for fat embolism syndrome, however, none of them are validated and accepted universally. [6] However, Gurd and Wilson's criteria for fat embolism become more commonly used when compared to the other two diagnostic criteria. [9]

Gurd and Wilson's criteria

Major criteria [6] [7] [9]

Minor criteria [6] [7] [9]

A least two positive major criteria plus one minor criteria or four positive minor criteria are suggestive of fat embolism syndrome. [6] Fat embolism syndrome is a clinical diagnosis. There are no laboratory tests sensitive or specific enough to diagnose FES. Such laboratory tests are only used to support the clinical diagnosis only. [7] Chest X-ray may show diffuse interstitial infiltrates while chest CT scan will show diffuse vascular congestion and pulmonary oedema. Bronchoalveolar lavage has been proposed to look for fat droplets in alveolar macrophages however it is time-consuming and is not specific to fat embolism syndrome. Looking for fat globules in sputum and urine is also not specific enough to diagnose FES. [6]

Prevention

For those treated conservatively with immobilisation of long bone fractures, the incidence of FES is 22%. Early operative fixation of long bone fractures can reduce the incidence of FES especially with the usage of internal fixation devices. Patients undergoing urgent fixation of long bone fractures has a rate of 7% of acute respiratory distress syndrome (ARDS) when compared to those undergoing fixation after 24 hours (39% with ARDS). However, movement of the fracture ends of the long bones during the operative fixation can cause transient increase of fat emboli in the blood circulation. Cytokines are persistently elevated if the long bone fractures is treated conservatively using immobilisation. The cytokine levels would return to normal after operative fixation. Although ream nailing increases pressure in the medullary cavity of the long bones, it does not increase the rates of FES. Other methods such as drilling of holes in the bony cortex, lavaging bone marrow prior to fixation, and the use of tourniquets to prevent embolisation have not been shown to reduce the rates of FES. [6]

Corticosteroid therapy such as methylprednisolone (6 to 90 mg/kg) has been proposed for the treatment of FES, however, it is controversial. Corticosteroid can be used to limit free fatty acid levels, stabilising membranes, and inhibit leukocyte aggregation. A meta-analysis conducted in 2009 reported prophylactic corticosteroids can reduce the risk of FES by 77%. However, there is no difference in mortality, infection, and avascular necrosis when compared to the control group. However, a randomised trial conducted in 2004 reported no differences in FES incidence when comparing treatment with the control group. [6] Administration of corticosteroids for 2 to 3 days is not associated with increased rates of infection. [5] However, there is insufficient data to support the use of methyprednisolone once FES is established. [5]

Heparin has been used in the prevention of venous thrombosis in post-operative patients; however its regular use in those with FES has been contraindicated due to increase risk of bleeding in those with polytrauma. [5] Placement of inferior vena cava filters has been proposed to reduce the amount of emboli going into the lung vascular system, however, this method has not been studied in detail. [6]

Treatment

Serum albumin PDB 1ao6 EBI.jpg
Serum albumin

Once FES develops, the person should be admitted into intensive care unit (ICU), preferably with central venous pressure (CVP) monitoring. CVP monitoring would be helpful to guide the volume resuscitation. [5] Supportive treatment is the only proven treatment method. Supplemental oxygen can be given if a person has mild respiratory distress. [6] However, if a person has severe respiratory distress, either continuous positive pressure ventilation (CPAP), or mechanical ventilation using positive end-expiratory pressure (PEEP) [5] may be indicated. Fluid replacement is required to prevent shock. [6] Volume resuscitation with human albumin is recommended because it can restore blood volume in the circulatory system while also binds to free fatty acids in order to reduce lung injuries. [5] [9] In severe cases, dobutamine should be used to support the right ventricular failure. Frequent Glasgow coma scale (GCS) charting is required to assess the neurological progression of a person with FES. A placement of intracranial pressure monitor may be helpful to direct the treatment of cerebral odema. [6]

History

In 1861, Zenker first reported on the autopsy findings of fat droplets found in the lungs of a railway worker who died due to severe thoraco-abdominal crush injury. In 1873, Bergmann diagnosed fat embolism clinically in a patient with fractured femur. In 1970, Gurd defined the characteristics of this phenomenon. [7] Gurd later modified the fat embolism criteria together with Wilson, thus producing Gurd and Wilson's criteria for fat embolism syndrome in 1974. [7] In 1983, Schonfeld suggested a scoring system for the diagnosis of fat embolism syndrome. In 1987, Lindeque proposed another scoring system that diagnose fat embolism syndrome by using respiratory changes alone. However, none of them have become universally accepted in the medical community. [6]

In 1978, Formula One racing driver Ronnie Peterson died from FES, after sustaining multiple fractures in a racing accident.

In 2015, Singaporean couple Pua Hak Chuan and Tan Hui Zhen were charged with the abuse and murder of Annie Ee Yu Lian, who died due to multiple physical abuses which lasted for eight months before her death. The cause of death was revealed to be acute fat embolism, which resulted from the blunt force impact caused by the beatings, which led to the fatty tissue entering the bloodstream and eventually entering the blood vessels in the lungs, which led to a blockage and cut off the circulation of oxygenated blood and led to Ee's death by respiratory and cardiac failure. Two years later, for reduced charges of voluntarily causing grievous hurt with a weapon, Tan was sentenced to 16 years and six months in jail while Pua received 14 years' imprisonment and 14 strokes of the cane. [10] [11]

Related Research Articles

<span class="mw-page-title-main">Embolism</span> Blockage of a blood vessel by a circulatory mass (embolus)

An embolism is the lodging of an embolus, a blockage-causing piece of material, inside a blood vessel. The embolus may be a blood clot (thrombus), a fat globule, a bubble of air or other gas, amniotic fluid, or foreign material.

<span class="mw-page-title-main">Embolus</span> Unattached mass that travels through the bloodstream

An embolus is an unattached mass that travels through the bloodstream and is capable of creating blockages. When an embolus occludes a blood vessel, it is called an embolism or embolic event. There are a number of different types of emboli, including blood clots, cholesterol plaque or crystals, fat globules, gas bubbles, and foreign bodies, which can result in different types of embolisms.

<span class="mw-page-title-main">Thrombus</span> Blood clot

A thrombus, colloquially called a blood clot, is the final product of the blood coagulation step in hemostasis. There are two components to a thrombus: aggregated platelets and red blood cells that form a plug, and a mesh of cross-linked fibrin protein. The substance making up a thrombus is sometimes called cruor. A thrombus is a healthy response to injury intended to stop and prevent further bleeding, but can be harmful in thrombosis, when a clot obstructs blood flow through a healthy blood vessel in the circulatory system.

<span class="mw-page-title-main">Respiratory failure</span> Inadequate gas exchange by the respiratory system

Respiratory failure results from inadequate gas exchange by the respiratory system, meaning that the arterial oxygen, carbon dioxide, or both cannot be kept at normal levels. A drop in the oxygen carried in the blood is known as hypoxemia; a rise in arterial carbon dioxide levels is called hypercapnia. Respiratory failure is classified as either Type 1 or Type 2, based on whether there is a high carbon dioxide level, and can be acute or chronic. In clinical trials, the definition of respiratory failure usually includes increased respiratory rate, abnormal blood gases, and evidence of increased work of breathing. Respiratory failure causes an altered state of consciousness due to ischemia in the brain.

<span class="mw-page-title-main">Pulmonary embolism</span> Blockage of an artery in the lungs

Pulmonary embolism (PE) is a blockage of an artery in the lungs by a substance that has moved from elsewhere in the body through the bloodstream (embolism). Symptoms of a PE may include shortness of breath, chest pain particularly upon breathing in, and coughing up blood. Symptoms of a blood clot in the leg may also be present, such as a red, warm, swollen, and painful leg. Signs of a PE include low blood oxygen levels, rapid breathing, rapid heart rate, and sometimes a mild fever. Severe cases can lead to passing out, abnormally low blood pressure, obstructive shock, and sudden death.

<span class="mw-page-title-main">Eosinophilia</span> Excess number of eosinophil cells in the blood

Eosinophilia is a condition in which the eosinophil count in the peripheral blood exceeds 5×108/L (500/μL). Hypereosinophilia is an elevation in an individual's circulating blood eosinophil count above 1.5 × 109/L (i.e. 1,500/μL). The hypereosinophilic syndrome is a sustained elevation in this count above 1.5 × 109/L (i.e. 1,500/μL) that is also associated with evidence of eosinophil-based tissue injury.

<span class="mw-page-title-main">Air embolism</span> Vascular blockage by air bubbles

An air embolism, also known as a gas embolism, is a blood vessel blockage caused by one or more bubbles of air or other gas in the circulatory system. Air can be introduced into the circulation during surgical procedures, lung over-expansion injury, decompression, and a few other causes. In flora, air embolisms may also occur in the xylem of vascular plants, especially when suffering from water stress.

<span class="mw-page-title-main">Acute respiratory distress syndrome</span> Respiratory failure due to widespread inflammation in the lungs

Acute respiratory distress syndrome (ARDS) is a type of respiratory failure characterized by rapid onset of widespread inflammation in the lungs. Symptoms include shortness of breath (dyspnea), rapid breathing (tachypnea), and bluish skin coloration (cyanosis). For those who survive, a decreased quality of life is common.

<span class="mw-page-title-main">Zellweger syndrome</span> Congenital disorder of nervous system

Zellweger syndrome is a rare congenital disorder characterized by the reduction or absence of functional peroxisomes in the cells of an individual. It is one of a family of disorders called Zellweger spectrum disorders which are leukodystrophies. Zellweger syndrome is named after Hans Zellweger (1909–1990), a Swiss-American pediatrician, a professor of pediatrics and genetics at the University of Iowa who researched this disorder.

<span class="mw-page-title-main">Hypoxemia</span> Abnormally low level of oxygen in the blood

Hypoxemia is an abnormally low level of oxygen in the blood. More specifically, it is oxygen deficiency in arterial blood. Hypoxemia has many causes, and often causes hypoxia as the blood is not supplying enough oxygen to the tissues of the body.

Eosinophilic pneumonia is a disease in which an eosinophil, a type of white blood cell, accumulates in the lungs. These cells cause disruption of the normal air spaces (alveoli) where oxygen is extracted from the atmosphere. Several different kinds of eosinophilic pneumonia exist and can occur in any age group. The most common symptoms include cough, fever, difficulty breathing, and sweating at night. Eosinophilic pneumonia is diagnosed by a combination of characteristic symptoms, findings on a physical examination by a health provider, and the results of blood tests and X-rays. Prognosis is excellent once most eosinophilic pneumonia is recognized and treatment with corticosteroids is begun.

<span class="mw-page-title-main">Respiratory disease</span> Disease of the respiratory system

Respiratory diseases, or lung diseases, are pathological conditions affecting the organs and tissues that make gas exchange difficult in air-breathing animals. They include conditions of the respiratory tract including the trachea, bronchi, bronchioles, alveoli, pleurae, pleural cavity, the nerves and muscles of respiration. Respiratory diseases range from mild and self-limiting, such as the common cold, influenza, and pharyngitis to life-threatening diseases such as bacterial pneumonia, pulmonary embolism, tuberculosis, acute asthma, lung cancer, and severe acute respiratory syndromes, such as COVID-19. Respiratory diseases can be classified in many different ways, including by the organ or tissue involved, by the type and pattern of associated signs and symptoms, or by the cause of the disease.

An embolus, is described as a free-floating mass, located inside blood vessels that can travel from one site in the blood stream to another. An embolus can be made up of solid, liquid, or gas. Once these masses get "stuck" in a different blood vessel, it is then known as an "embolism." An embolism can cause ischemia—damage to an organ from lack of oxygen. A paradoxical embolism is a specific type of embolism in which the embolus travels from the right side of the heart to the left side of the heart and lodges itself in a blood vessel known as an artery. Thus, it is termed "paradoxical" because the embolus lands in an artery, rather than a vein.

<span class="mw-page-title-main">CT pulmonary angiogram</span> Medical imaging of blood flow between heart and lungs

A CT pulmonary angiogram (CTPA) is a medical diagnostic test that employs computed tomography (CT) angiography to obtain an image of the pulmonary arteries. Its main use is to diagnose pulmonary embolism (PE). It is a preferred choice of imaging in the diagnosis of PE due to its minimally invasive nature for the patient, whose only requirement for the scan is an intravenous line.

Wilson–Mikity syndrome, a form of chronic lung disease (CLD) that exists only in premature infants, leads to progressive or immediate development of respiratory distress. This rare condition affects low birth babies and is characterized by rapid development of lung emphysema after birth, requiring prolonged ventilation and oxygen supplementation. It is closely related to bronchopulmonary dysplasia (BPD), differing mainly in the lack of prior ventilatory support. All the initial patients described with Wilson–Mikity syndrome were very low birth weight infants that had no history of mechanical ventilation, yet developed a syndrome that clinically resembled BPD. Upon the death of some of these infants, autopsies showed histologic changes similar to those seen in BPD.

<span class="mw-page-title-main">Cholesterol embolism</span> Medical condition

Cholesterol embolism occurs when cholesterol is released, usually from an atherosclerotic plaque, and travels as an embolus in the bloodstream to lodge causing an obstruction in blood vessels further away. Most commonly this causes skin symptoms, gangrene of the extremities and sometimes kidney failure; problems with other organs may arise, depending on the site at which the cholesterol crystals enter the bloodstream. When the kidneys are involved, the disease is referred to as atheroembolic renal disease. The diagnosis usually involves biopsy from an affected organ. Cholesterol embolism is treated by removing the cause and giving supportive therapy; statin drugs have been found to improve the prognosis.

Embolectomy is the emergency interventional or surgical removal of emboli which are blocking blood circulation. It usually involves removal of thrombi, and is then referred to as thromboembolectomy or thrombectomy. Embolectomy is an emergency procedure often as the last resort because permanent occlusion of a significant blood flow to an organ leads to necrosis. Other involved therapeutic options are anticoagulation and thrombolysis.

<span class="mw-page-title-main">Purtscher's retinopathy</span> Medical condition

Purtscher's retinopathy is a disease where part of the eye (retina) is damaged. Usually associated with severe head injuries, it may also occur with other types of trauma, such as long bone fractures, or with several non-traumatic systemic diseases. However, the exact cause of the disease is not well understood. There are no treatments specific for Purtscher's retinopathy, and the prognosis varies. The disease can threaten vision, sometimes causing temporary or permanent blindness.

<span class="mw-page-title-main">Arterial embolism</span> Interruption of blood flow to an organ

Arterial embolism is a sudden interruption of blood flow to an organ or body part due to an embolus adhering to the wall of an artery blocking the flow of blood, the major type of embolus being a blood clot (thromboembolism). Sometimes, pulmonary embolism is classified as arterial embolism as well, in the sense that the clot follows the pulmonary artery carrying deoxygenated blood away from the heart. However, pulmonary embolism is generally classified as a form of venous embolism, because the embolus forms in veins. Arterial embolism is the major cause of infarction.

Lymphocyte-variant hypereosinophilia is a rare disorder in which eosinophilia or hypereosinophilia is caused by an aberrant population of lymphocytes. These aberrant lymphocytes function abnormally by stimulating the proliferation and maturation of bone marrow eosinophil-precursor cells termed colony forming unit-eosinophils or CFU-Eos.

References

  1. 1 2 3 4 5 6 7 Akhtar, S (September 2009). "Fat embolism". Anesthesiology Clinics. 27 (3): 533–50, table of contents. doi:10.1016/j.anclin.2009.07.018. PMID   19825491.
  2. 1 2 3 4 5 6 7 8 9 Laurence, Knott (19 February 2014). "Fat embolism syndrome". patient.info. Archived from the original on 1 December 2017. Retrieved 14 March 2018.
  3. 1 2 3 4 5 Adeyinka, A; Pierre, L (2020). "Fat Embolism". StatPearls. PMID   29763060.
  4. 1 2 3 4 Fukumoto, LE; Fukumoto, KD (September 2018). "Fat Embolism Syndrome". The Nursing Clinics of North America. 53 (3): 335–347. doi:10.1016/j.cnur.2018.04.003. PMID   30100000. S2CID   51969468.
  5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 George, Jacob; George, Reeba; Dixit, R.; Gupta, R. C.; Gupta, N. (2013). "Fat embolism syndrome". Lung India. 30 (1): 47–53. doi: 10.4103/0970-2113.106133 . ISSN   0970-2113. PMC   3644833 . PMID   23661916.
  6. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Michael E, Kwiatt; Mark J, Seamon (March 2013). "Fat embolism syndrome". International Journal of Critical Illness and Injury Science. 3 (1): 64–68. doi: 10.4103/2229-5151.109426 . PMC   3665122 . PMID   23724388.
  7. 1 2 3 4 5 6 7 8 9 10 11 12 Korhan, Taviloglu; Hakan, Yanar (1 January 2007). "Fat embolism syndrome". Surgery Today. 37 (1): 5–8. doi:10.1007/s00595-006-3307-5. PMID   17186337. S2CID   8190157.
  8. Joseph, Deepak; Puttaswamy, Raju K; Krovvidi, Hari (2013). "Non-respiratory functions of the lung". Continuing Education in Anaesthesia, Critical Care & Pain. 13 (3). Elsevier BV: 98–102. doi: 10.1093/bjaceaccp/mks060 . ISSN   1743-1816.
  9. 1 2 3 4 Saigal, R; Mittal, M; Kansai, A; Singh, Y; Kolar, PR; Jain, S (April 2008). "Fat embolism syndrome" (PDF). Journal of the Association of Physicians of India. 56 (392): 245–249. PMID   18702388. Archived (PDF) from the original on 12 October 2017. Retrieved 14 March 2018. Diagnosis is usually made on the basis of clinical findings but biochemical changes may be of value. The most commonly used set of major and minor diagnostic criteria are those published by Gurd (See Table 2 ).
  10. "14, 16.5 years' jail for couple who tortured tenant to death". Today. Singapore. 1 December 2017. Archived from the original on 15 August 2022. Retrieved 20 April 2022.
  11. "AGC replies to questions raised by the public". The Straits Times. Singapore. 19 December 2017. Archived from the original on 13 August 2022. Retrieved 20 April 2022.

Further reading