A case of fatal fulminant fat embolism syndrome saved by VA-ECMO in the acute phase of multiple trauma

Fat embolism syndrome (FES) is a rare complication of long bone fractures, with fulminant FES developing within 12 h of injury and often proving fatal (Shaikh, 2009 [1]). Here, we present a case of fulminant FES in a patient who developed sudden right heart failure after undergoing external fixation of a lower leg fracture and required veno-arterial extracorporeal membrane oxygenation (VA-ECMO). A 79-year-old woman injured in a traffic accident was transferred to our emergency department. Upon arrival, her level of consciousness deteriorated, and she developed circulatory failure. We promptly performed transcatheter arterial embolization for the pelvic fracture and external fixation of the tibiofibular fracture. Within four hours of the injury, she was admitted to our intensive care unit (ICU). Two hours after ICU admission, her hemodynamic status worsened, necessitating the administration of maximum catecholamine dose. Echocardiography revealed petechial hemorrhage of the palpebral conjunctiva and enlargement of the right ventricle. Despite maximal supportive care, the patient remained cardiovascularly unstable. Therefore, VA-ECMO was initiated to stabilize her hemodynamic status. Thereafter, her hemodynamics stabilized, and ECMO support was weaned off and removed on day 3. Subsequent magnetic resonance imaging revealed evidence of cerebral fat embolism. On day 9, she underwent open reduction of the left lower leg with internal fixation and was transferred to another hospital on day 29. This report documents the successful management of fulminant FES during the acute phase of multiple traumas. Clinicians should consider VA-ECMO when suspecting uncontrolled circulatory failure due to fulminant FES, even in the acute phase of multiple trauma.

[Clinical manifestation and imaging diagnostic analysis of fat embolism syndrome]

OBJECTIVE

To explore characteristics of clinical and imaging findings in patients with fat embolism syndrome.

METHODS

From January 2021 to October 2022,clinical manifestations of 13 patients with fat embolism due to fracture or orthopaedic surgery were retrospectively analyzed,including 11 males and 2 females,aged from 17 to 60 years old. Mental and respiratory abnormalities and changes in vital signs occurred after admission or after surgery,and patient's chest and brain imaging results were abnormal. The patient's mental and respiratory abnormalities,vital signs,chest and brain imaging results were continuously monitored.

RESULTS

The main clinical manifestations of fat embolism syndrome were abnormal pulmonary respiration in 13 patients,abnormal central nervous function in 7 patients,and spotted rash in 2 patients. Chest CT showed diffuse distribution of ground glass shadows in 13 patients,and severe symptoms were "snowstorm". Nine patients with ground glass fusion consolidation,5 patients with multiple nodules and 4 patients accompanied by bilateral pleural effusion. Head CT findings of 5 patients were negative,and head MRI findings of 1 patient showed multiple T1WI low signal,T2WI high signal shadow,DWI high signal shadow,and "starry sky sign" in basal ganglia,radiative crown,hemioval center,thalamus,frontal parietal cortex and subcortex.

CONCLUSION

Fat embolism syndrome has a high mortality rate. Clinical manifestations of respiratory system and nervous system are not specific,and the skin spot rash has a characteristic manifestation. The "blizzard" sign is the specific manifestation of chest X-ray and CT examination of fat embolism,and the "starry sky" sign is the typical manifestation of diffusion-weighted sequence of brain MRI examination of fat embolism.

Intraoperative fat embolism syndrome associated with implantation of titanium sacroiliac joint fusion implants: a report of two cases

Background

For patients undergoing long-construct fusion surgeries, simultaneous sacroiliac joint (SIJ) fusion is a growing trend in spine surgery. Some options for posterior SIJ fusion include 3D-printed triangular titanium implants or self-harvesting SIJ screws. Both implants require fixation within the sacrum and ileum. Fat embolism syndrome is a rare but known complication of lumbar pedicle instrumentation but has never been reported in association with SIJ fusion, regardless of implant type. We report the first two known cases of fat embolism associated with placement of SIJ fusion devices during long construct posterior spine fusion.

Case Description

Case 1-a 50-year-old female with multiple previous spine surgeries complicated by osteomyelitis/diskitis that was successfully eradicated, underwent T10-pelvis posterior spinal fusion (PSF), L4 pedicle-subtracting-osteotomy, and bilateral SIJ fusion. During implantation of each SIJ fusion device, the patient's hemodynamic status deteriorated necessitating vasopressor support, intravenous fluid bolus, and hyperventilation, but quickly resolved. The case was completed without further issue, and she had an uneventful post-operative course. Case 2-a 71-year-old female with a past medical history of ankylosing spondylitis, previous L2-L5 PSF, rheumatoid arthritis on chronic steroids, underwent a T9-pelvis PSF, bilateral SIJ fusion, L4 pedicle subtraction osteotomy, T10-L1 Smith Peterson osteotomies. After implantation of the second SIJ fusion device, she became hypotensive and tachycardic, pulses were absent, and cardiopulmonary resuscitation was initiated. Pulses returned quickly, the index surgery was terminated, and she was transferred to the intensive care unit (ICU). In the ICU she was quickly weaned off the ventilator on post-operative day 1. On post-operative day 4, the patient returned to the operating room for completion of the surgery and had an extended, but uneventful, recovery afterwards.

Conclusions

We report on the first two known cases of fat embolism syndrome occurring immediately after implantation of SIJ fusion devices. Spine surgeons should be aware of this rare, but potentially fatal, complication. Collaboration with the anesthesia team and optimization of the patient's hemodynamic status prior to implantation may help prevent catastrophic complications.

Diagnosis of Bone Marrow Necrosis following Severe Vaso-Occlusive Crisis in Patient with Compound Heterozygous Sickle Cell Disease

Introduction

Bone marrow necrosis is a rare entity that can develop in context of a sickle cell disease vaso-occlusive crisis. Its physiopathology is related to an endothelial dysfunction taking place in bone marrow microvasculature.

Case Presentation

A 30-year-old patient with history of compound heterozygous sickle cell disease was admitted following SARS-CoV-2 infection with fever and diarrhea. After initial favorable evolution, he developed a severe vaso-occlusive crisis with intense hemolysis and multi-organ ischemic complications. Patient then developed high fever and hypoxemia. With the suspicion of acute thoracic syndrome, a red blood cell exchange was performed. Respiratory symptoms ceased but patient persisted febrile with very high levels of acute phase reactants, persistent pancytopenia, and leucoerythroblastic reaction. An infectious cause was ruled out. Afterward, bone marrow aspiration and bone marrow biopsy showed a picture of bone marrow necrosis, which is an extremely rare complication of vaso-occlusive crisis but, paradoxically, more frequent in milder heterozygote cases of sickle cell disease. Ultimately, large deposits of complement membrane attack complex (particles C5b-9) were demonstrated after incubation of laboratory endothelial cells with activated plasma from the patient.

Discussion

The clinical presentation and findings are consistent with a case of bone marrow necrosis. In this setting, the demonstration of complement as a potential cause of the endothelial dysfunction mimics the pattern of atypical hemolytic uremic syndrome and other microangiopathic anemias. This dysregulation may be a potential therapeutic target for new complement activation blockers.

[Intervention effect of injury control orthopedic strategy on fat embolism syndrome associated with long shaft fracture of lower limb]

OBJECTIVE

To observe the intervention effect of damage control orthopaedic(DCO) strategy on fat embolism syndrome(FES) associated with long shaft fracture of lower limbs.

METHODS

Retrospective analysis was made on the clinical data of 163 patients with FES associated with lower limb long shaft fractures admitted from January 2015 to May 2021. They were divided into two groups based on the time point of implementing DCO strategy in January 2018. Total of 92 patients were admitted from January 2015 to December 2017 as the control group, and other 71 patients were admitted from January 2018 to May 2021 as the intervention group. The hospital mortality, arterial oxygen saturation (SaO₂), arterial partial pressure of oxygen (PaO₂) and oxygenation index (OI), hemoglobin (Hb), platelet count(PLT), Harris score of hip joint, HSS score of knee joint, AOFAS score of ankle joint, clinical efficacy and complications were observed and compared between two groups.

RESULTS

Total of 163 patients were followed up for 12 to 18 months with an average of (16.91±1.22) months. The in-hospital mortality rate in the intervention group was 2.82% (2/71), and that in the control group was 16.30% (15/92), the difference between two groups was statistically significant(χ²=6.455, P<0.05). After the intervention, SaO₂, PaO₂ and OI in two groups were higher than those before the intervention(P<0.05), and after the intervention, SaO₂, PaO₂ and OI in two groups were statistically significant(P<0.05). Hb and PLT in two groups after intervention were higher than those before intervention (P<0.001), and there was statistically significant difference in Hb and PLT between two groups after intervention (P<0.05). The Harris score of hip joint, HSS score of knee joint and AOFAS score of ankle joint in both groups after 3 months of treatment were better than those before treatment (P<0.05). The total clinical effective rate of the intervention group was higher than that of the control group(χ²=4.194, P<0.05). The total incidence of complications in the intervention group was lower than that in the control group(χ²=4.747, P<0.05).

CONCLUSION

DCO strategy is helpful to reduce the in-hospital mortality of patients with FES associated with long shaft fracture of lower extremities, eliminate FES symptoms and stabilize vital signs, gain time advantage for phase Ⅱ definitive surgery, and has significant clinical intervention effect, which is worth popularizing.

Pulmonary CT imaging findings in fat embolism syndrome: case series and literature review

BACKGROUND

Fat embolism syndrome (FES) is a rare life-threatening complication, which commonly affects the lung. Currently, the most widely accepted criteria for the diagnosis of FES are the Gurd and Wilson Criteria established nearly 40 years ago, but without pulmonary images involved. Our study aims to analyse the pulmonary computed tomography (CT) findings seen in FES.

CASE PRESENTATION

This report enrolled four cases of FES with lung involvement. The mainly symptoms and signs included dyspnea, disturbance of consciousness, anemia, thrombocytopenia and, most notably, ground-glass opacities, septal thickening, ill-defined centrilobular nodules, and patchy consolidation were demonstrated on bilateral lungs. Combining the clinical manifestations and laboratory tests, the diagnosis of FES was confirmed. With the treatment of steroids, anti-coagulation and supportive treatment, the four patients' symptoms were relieved, abnormalities in chest CT were absorbed significantly and the patients were finally discharged.

CONCLUSIONS

There are several common manifestations of FES in pulmonary CT images, and the lung parenchymal features give more information for the diagnosis of FES than the pulmonary vessel findings. Given the absence of a gold standard diagnostic test for FES, further investigation to explore new diagnostic criteria of FES involving pulmonary radiological features is needed in the future.

Simultaneous bilateral floating knee: A case report

BACKGROUND

The phrase “floating knee is a flail knee joint,” referring to ipsilateral femoral and tibial fractures, was first used by Blake and McBryde in 1975. This condition is often caused by a high-energy trauma with often extensive injury to the soft tissues, and is accompanied by life-threatening systemic complications, including head, chest or abdominal injuries and a high incidence of fat embolism. Floating knee is a severe and uncommon injury pattern.

CASE SUMMARY

A 27-year-old man sustained multiple injuries when the electric motorcycle he was riding was hit by a van. His injuries included traumatic hypovolemic shock, comminuted and open type II fractures of the left femoral shaft, fracture of the right femoral shaft, comminuted fracture of the bilateral tibial and fibular shaft, and multiple lacerations and abrasions on his forehead, lower lip, neck and limbs. The diagnosis was simultaneous bilateral floating knee complicated with soft tissue injuries. After emergency treatment and the exclusion of life-threating complications, open reduction and internal fixation were successfully performed using plates and screws in the bilateral femoral and tibial shafts.

CONCLUSION

Simultaneous bilateral floating knee is a rare and severe injury pattern. The treatment is challenging, and complications. We present a case report of a young adult who suffered from bilateral floating knees during road traffic accident. We also offer our treatment experience of this complex injury and review past literature.

Defining the boundaries of medical accountability by hospital autopsy

BACKGROUND

Fat Embolism Syndrome (FES) is a clinical condition characterized by neurological, respiratory, hematological and cutaneous manifestations. Fatal FES has been described as a rare complication during or after spinal elective surgery. The investigation of the cause of death in fatalities related with spine surgery should be mandatory to exclude or confirm fat embolism; a detailed methodological approach to the body in these cases suggests to provide a cautious dissection of surgical site and collection of samples to detect embolized fat globules in vessels.

METHODS

Two fatal cases of fat embolism syndrome after posterior spinal fusion are presented.

CONCLUSIONS

A complete post mortem examination by means of histochemical and immunohistochemical analysis explained the cause of death and prevented medical malpractice litigation.

Intraosseous fluid resuscitation causes systemic fat emboli in a porcine hemorrhagic shock model

BACKGROUND

Intraosseous cannulation can be life-saving when intravenous access cannot be readily achieved. However, it has been shown that the procedure may cause fat emboli to the lungs and brain. Fat embolization may cause serious respiratory failure and fat embolism syndrome. We investigated whether intraosseous fluid resuscitation in pigs in hemorrhagic shock caused pulmonary or systemic embolization to the heart, brain, or kidneys and if this was enhanced by open chest conditions.

METHODS

We induced hemorrhagic shock in anesthetized pigs followed by fluid-resuscitation through bilaterally placed tibial (hind leg) intraosseous cannulas. The fluid-resuscitation was limited to intraosseous or i.v. fluid therapy, and did not involve cardiopulmonary resuscitation or other interventions. A subgroup underwent median sternotomy with pericardiectomy and pleurotomy before hemorrhagic shock was induced. We used invasive hemodynamic and respiratory monitoring including Swan Ganz pulmonary artery catheter and transesophageal echocardiography and obtained biopsies from the lungs, heart, brain, and left kidney postmortem.

RESULTS

All pigs exposed to intraosseous infusion had pulmonary fat emboli in postmortem biopsies. Additionally, seven of twenty-one pigs had coronary fat emboli. None of the pigs with open chest had fat emboli in postmortem lung, heart, or kidney biopsies. During intraosseous fluid-resuscitation, three pigs developed significant ST-elevations on ECG; all of these animals had coronary fat emboli on postmortem biopsies.

CONCLUSIONS

Systemic fat embolism occurred in the form of coronary fat emboli in a third of the animals who underwent intraosseous fluid resuscitation. Open chest conditions did not increase the incidence of systemic fat embolization.

Single-case metanalysis of fat embolism syndrome

BACKGROUND

Only one large series has been reported on fat embolism syndrome (FES), a condition caused by fat globules release into the circulation, primarily as consequence of bone fracture. Thus, more data on clinical features, therapies, and prognosis are needed.

METHODS AND RESULTS

The study screened 1090 manuscripts in PubMed and Web of Science on cases of FES published from June 2010 to June 2020. The authors identified 124 studies and included in the pooled-analysis 135 patients (>14 years), plus one additional unpublished case managed in Tongji hospital. All had confirmed diagnosis of FES with complete clinical data. The median age at presentation was 39 years, and 82 (61.8%) were men. FES was predominantly associated with bone fractures (78, 57.4%), particularly femur fracture (59, 43.4%). The most common clinical finding at the onset was respiratory abnormalities in 34.6% of all clinical presentations. Therapies included respiratory supportive care in 127 (93.4%) patients, application of corticosteroids in 22 (16.2%) and anticoagulant in 5 (3.7%) cases. Overall mortality was 30.2% (N = 41), and logistic regression analysis showed that corticosteroid therapy was significantly associated with reduced mortality with an OR of 0.143 (95%CI 0.029-0.711), while age ≥ 65 years and non-orthopedic conditions were significantly associated with increased mortality with an OR of 4.816 (95%CI 1.638-14.160) and 4.785 (95%CI 1.019-22.474).

CONCLUSIONS

FES has been associated with a larger mortality rate than previously observed, although publication bias can have led to overestimation of mortality. Finally, a potential protective effect of corticosteroid therapy has been suggested by the current analysis.

Early acute fat embolism syndrome caused by femoral fracture: A case report

BACKGROUND

Fat embolism syndrome (FES) is a rare complication caused by the presence of fat particles in the microcirculation, which usually occurs within 12-72 h after trauma. At present, there have been few cases of fat embolism presenting within 3 h after trauma. Here, we report a case of femoral fracture complicated with an acute fat embolism caused by a car accident.

CASE SUMMARY

A 29-year-old woman with pain, swelling and limited movement of her left lower limb after a car accident was taken by ambulance to our hospital. X-ray examination showed fracture of the middle and lower part of the left femur and fracture of the base of the left fifth metatarsal bone. She was hospitalized and admitted to the orthopedic ward. After the attending doctor performed tibial tubercle bone traction, the patient became confused, followed by respiratory distress. Finally, she was transferred to the intensive care unit. After nearly a month of treatment in the intensive care unit, the patient's cognitive function gradually recovered over 6 mo.

CONCLUSION

For patients with early traumatic fractures, young emergency physicians and orthopedics should be aware of the possibility of FES.

Guidelines for the acute care of severe limb trauma patients

GOAL

To provide healthcare professionals with comprehensive multidisciplinary expert recommendations for the acute care of severe limb trauma patients, both during the prehospital phase and after admission to a Trauma Centre.

DESIGN

A consensus committee of 21 experts was formed. A formal conflict-of-interest (COI) policy was developed at the onset of the process and enforced throughout. The entire guidelines process was conducted independently of any industrial funding (i.e., pharmaceutical, medical devices). The authors were advised to follow the rules of the Grading of Recommendations Assessment, Development and Evaluation (GRADE®) system to guide assessment of the quality of evidence. The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasised. Few recommendations remained non-graded.

METHODS

The committee addressed eleven questions relevant to the patient suffering severe limb trauma: 1) What are the key findings derived from medical history and clinical examination which lead to the patient's prompt referral to a Level 1 or Level 2 Trauma Centre? 2) What are the medical devices that must be implemented in the prehospital setting to reduce blood loss? 3) Which are the clinical findings prompting the performance of injected X-ray examinations? 4) What are the ideal timing and modalities for performing fracture fixation? 5) What are the clinical and operative findings which steer the surgical approach in case of vascular compromise and/or major musculoskeletal attrition? 6) How to best prevent infection? 7) How to best prevent thromboembolic complications? 8) What is the best strategy to precociously detect and treat limb compartment syndrome? 9) How to best and precociously detect post-traumatic rhabdomyolysis and prevent rhabdomyolysis-induced acute kidney injury? 10) What is the best strategy to reduce the incidence of fat emboli syndrome and post-traumatic systemic inflammatory response? 11) What is the best therapeutic strategy to treat acute trauma-induced pain? Every question was formulated in a PICO (Patient Intervention Comparison Outcome) format and the evidence profiles were produced. The literature review and recommendations were made according to the GRADE® methodology.

RESULTS

The experts' synthesis work and the application of the GRADE method resulted in 19 recommendations. Among the formalised recommendations, 4 had a high level of evidence (GRADE 1+/-) and 12 had a low level of evidence (GRADE 2+/-). For 3 recommendations, the GRADE method could not be applied, resulting in an expert advice. After two rounds of scoring and one amendment, strong agreement was reached on all the recommendations.

CONCLUSIONS

There was significant agreement among experts on strong recommendations to improve practices for severe limb trauma patients.

Complete neurological recovery from fat embolism syndrome in sickle cell disease after sequential red cell exchange transfusion and therapeutic plasma exchange

Fat embolism syndrome in sickle cell disease is associated with great mortality, while more than half of survivors suffer severe neurological sequelae. Release of fat droplets leads to obstruction of the microcirculation as well as generation of proinflammatory cytokines that can cause direct tissue injury. Red cell exchange transfusion can be life-saving but the addition of therapeutic plasma exchange may further improve outcomes by removing such inflammatory mediators. Here, we describe the case of a 27-year-old male patient with sickle cell anaemia presenting with typical features of fat embolism syndrome including neurological involvement with greatly reduced level of consciousness. MRI of his brain showed multiple widespread microhemorrhages giving the characteristic "star field" pattern but also a cytotoxic lesion of the corpus callosum, known to be the result of direct neurotoxicity by proinflammatory cytokines. The patient underwent emergency red cell exchange transfusion leading only to modest clinical improvement but fully regained consciousness after three cycles of therapeutic plasma exchange. This case highlights the deleterious effect of the hyperinflammatory state characteristic of many sickle cell complications and supports further exploring the potential benefit from plasma exchange as an adjunct to red cell exchange in order to remove proinflammatory cytokines during acute complications of sickle cell disease.

Late-onset isolated cerebral fat embolism syndrome after a simple tibial plateau fracture: a rare case report

Fat embolism syndrome (FES) is a complication of long bone fractures that often occurs within 72 hours of injury. Early-onset isolated cerebral fat embolism is catastrophic and rarely reported. We herein present a rare case of delayed-onset isolated cerebral FES that developed 10 days after definite fixation of a left tibial plateau fracture. A 70-year-old woman was injured in a traffic accident and diagnosed with a left tibial plateau fracture. However, she developed sudden loss of consciousness (E4V1M1) and quadriplegia 10 days after fracture fixation. Her vital signs showed no respiratory distress. Diagnosis of isolated cerebral FES was made based on magnetic resonance imaging of the brain, the findings of which were compatible with the clinical neurological findings. After supportive care and rehabilitation, her consciousness became clear on the second day of admission, and her consciousness changed to E4V5M6. She gradually regained strength in her right limbs but had residual left limb paraplegia. Isolated cerebral FES should always be considered for patients who develop a change in consciousness, even beyond 72 hours after injury. Imaging may not initially show definitive abnormalities. Repeated magnetic resonance imaging should be considered if the initial clinical presentation does not fully meet Gurd's criteria.

Cerebral fat embolism after traumatic bone fractures: a structured literature review and analysis of published case reports

Background

The incidence of cerebral fat embolism (CFE) ranges from 0.9–11%, with a mean mortality rate of around 10%. Although no univocal explanation has been identified for the resulting fat embolism syndrome (FES), two hypotheses are widely thought: the ‘mechanical theory’, and the ‘chemical theory’. The present article provides a systematic review of published case reports of FES following a bone fracture.

Methods

We searched MEDLINE, Web of Science and Scopus to find any article related to FES. Inclusion criteria were: trauma patients; age ≥ 18 years; and the clinical diagnosis of CFE or FES. Studies were excluded if the bone fracture site was not specified.

Results

One hundred and seventy studies were included (268 cases). The male gender was most prominent (81.6% vs. 18.4%). The average age was 33 years (±18). The mean age for males (29 ± 14) was significantly lower than for females (51 ± 26) (p < 0.001). The femur was the most common fracture site (71% of cases). PFO was found in 12% of all cases. Univariate and multivariate regression analyses showed the male gender to be a risk factor for FES: RR 1.87 and 1.41, respectively (95%CI 1.27–2.48, p < 0.001; 95%CI 0.48–2.34, p < 0.001).

Conclusions

FES is most frequent in young men in the third decades of life following multiple leg fractures. FES may be more frequent after a burst fracture. The presence of PFO may be responsible for the acute presentation of cerebral embolisms, whereas FES is mostly delayed by 48–72 h.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-021-00861-x.

Post-traumatic cerebral fat embolism syndrome with a favourable outcome: a case report

Background

Fat embolism syndrome (FES) is a change in physiology resulting from mechanical causes, trauma, or sepsis. Neurological manifestations of FES can vary from mild cognitive changes to coma and even cerebral oedema and brain death. Here, we present an unusual case of cerebral fat emboli that occurred in the absence of acute chest syndrome or right-to-left shunt.

Case presentation

A previously healthy 57-year-old right-handed male was admitted to our department because of unconsciousness after a car accident for 3 days. He suffered from multiple fractures of the bilateral lower extremities and pelvis. This patient had severe anaemia and thrombocytopenia. Head MRI showed multiple small lesions in the whole brain consistent with a “star field” pattern, including high signals on T2-weighted (T2w) and fluid-attenuated inversion recovery (FLAIR) images in the bilateral centrum semiovale; both frontal, parietal and occipital lobes; and brainstem, cerebellar hemisphere, and deep and subcortical white matter. Intravenous methylprednisolone, heparin, mannitol, antibiotics and nutritional support were used. Although this patient had severe symptoms at first, the outcome was favourable.

Conclusions

When patients have long bone and pelvic fractures, multiple bone fractures and deteriorated neurological status, cerebral fat embolism (CFE) should be considered. Additionally, CFE may occur without an intracardiac shunt. The early diagnosis and appropriate management of FES are important, and prior to and following surgery, patients should be monitored comprehensively in the intensive care unit. With appropriate treatment, CFE patients may achieve good results.

Risk Stratification Algorithm for Orthopedic Trauma Patients at Risk for Fat Embolism Syndrome

BACKGROUND

Fat embolism syndrome (FES) is commonly reported in the setting of long bone and pelvic fractures, but the etiology and pathogenesis are unclear. The aim of this study was to identify clinical characteristics and laboratory findings that may place orthopedic trauma patients at a higher risk of developing FES.

METHODS

Electronic medical records were reviewed of all patients aged 18-89 years from 2015 to 2020 with a mention of FES in the patient chart who met Gurd and Wilson's criteria for diagnosis after experiencing orthopedic trauma. A 3:1 matched pair analysis was performed between FES patients and those with similar age, gender, and FES-associated fracture (femur, tibia, humerus, or pelvis fracture).

RESULTS

18 patients with FES who met inclusion criteria were identified. Hypomagnesemia (OR = 7.43), hyperphosphatemia (OR = 6.24), hypoalbuminemia (OR = 3.78), blunt traumatic mechanism of injury (OR = 7.16) and a greater number of bones fractured (Avg/SD = 2.89/1.53) were seen more often in FES patients (all p-values < 0.05).

CONCLUSION

Findings of this study suggest that patients with hypomagnesemia, hyperphosphatemia, hypoalbuminemia, a blunt trauma mechanism of injury, and an increased number of bones fractured are at increased risk for the development of FES. This may be related to their roles in physiologic oncotic pressure and inflammatory response, and thus further investigation of these variables is necessary for the evaluation of FES prevention.

LEVEL OF EVIDENCE

Level 3.

Postoperative complications of concomitant fat embolism syndrome, pulmonary embolism and tympanic membrane perforation after tibiofibular fracture: A case report

BACKGROUND

Fat embolism syndrome (FES) is a rare disease characterized by pulmonary distress, neurologic symptoms, and petechial rash and seriously threatens human life and health. It is still neglected clinically because of the lack of verifiable diagnostic criteria and atypical clinical symptoms. No studies on FES with pulmonary embolism (PE) and tympanic membrane perforation have been reported to date. Here, we report a rare case of concomitant FES, PE and tympanic membrane perforation after surgery in a patient with a tibiofibular fracture.

CASE SUMMARY

A 39-year-old man presented with right lower extremity pain due to a car accident while driving a motorbike on the road. X-ray and computed tomography scans revealed a fracture of the right mid-shaft tibia and proximal fibula categorized as a type A2 fracture according to the AO classification. A successful minimally invasive operation was performed 3 d after the injury. Postoperatively, the patient developed sudden symptoms of respiratory distress and hearing loss. Early diagnosis was made, and supportive treatments were used at the early stage of FES. Seven days after surgery, he presented a clear recovery from respiratory symptoms. The outcome of fracture healing was excellent, and his hearing of the left ear was mildly impaired at the last follow-up of 4 mo.

CONCLUSION

Concomitant FES, PE and tympanic membrane perforation are very rare but represent potentially fatal complications of trauma or orthopedic surgery and present with predominantly pulmonary symptoms. Early diagnosis and treatment can reduce the mortality of FES, and prevention is better than a cure.

Management of long bone fractures in patients with cerebral fat embolism syndrome

Fat embolism syndrome (FES) is a rare complication associated with long bone fractures. Intramedullary nailing is the gold standard for treating patients with these injuries and early surgical intervention can prevent FES. However, there is a paucity of data on managing these patients once FES has developed. The purpose of this study is to present 3 unique cases of polytrauma patients with long bone fractures who underwent fixation with Taylor Spatial Frame, open reduction and internal fixation, or submuscular plating for treatment of these injuries. All 3 patients had complete cognitive and physical recovery.

A mysterious case of fat embolism

We report a patient who sustained catastrophic pulmonary fat embolism post-induction of general anesthesia during laparotomy for haemoperitoneum. The source being the fractured shaft of fracture femur which was missed during the primary survey in the chaos of a positive focused assessment with sonography for trauma and a transient responding patient. In this case report, we want to emphasize the importance of primary survey in a trauma patient, effective communication and documentation to prevent errors and for better management of patients.

Fat embolism syndrome in blunt trauma patients with extremity fractures

OBJECTIVE

This study sought to provide a national, descriptive analysis to determine fat embolism syndrome (FES) risk factors, hypothesizing that femur fractures and multiple fractures are associated with an increased risk.

METHODS

The Trauma Quality Improvement Program was queried (2010-2016) for patients with extremity fractures. A multivariable logistic regression analysis model was used.

RESULTS

From 324,165 patients, 116 patients (0.04%) were diagnosed with FES. An age ≤30, closed femur fracture, and multiple long bone fractures were associated with an increased risk of FES.

CONCLUSION

Future research to validate these findings and develop a clinical risk stratification tool appears warranted.

COVID-19 suspicion revealed to be fat embolism syndrome

The novel coronavirus, named SARS-CoV-2, responsible of the COVID-19 is now causing a pandemic. Detecting all possible cases and eliminating differential diagnoses in front of any acute respiratory distress has become a daily challenge for doctors around the world. We believe that non-COVID patients are the hidden victims of the actual health problematic. We report from this manuscript the case of a patient with fat embolism syndrome that has been suspected as COVID-19.

Cerebral Fat Embolism: Recognition, Complications, and Prognosis

Fat embolism syndrome (FES) is a rare syndrome caused by embolization of fat particles into multiple organs including the brain. It typically manifests with petechial rash, deteriorating mental status, and progressive respiratory insufficiency, usually occurring within 24-48 h of trauma with long-bone fractures or an orthopedic surgery. The diagnosis of FES is based on clinical and imaging findings, but requires exclusion of alternative diagnoses. Although there is no specific treatment for FES, prompt recognition is important because it can avoid unnecessary interventions and clarify prognosis. Patients with severe FES can become critically ill, but even comatose patients with respiratory failure may recover favorably. Prophylactic measures, such as early stabilization of fractures and certain intraoperative techniques, may help decrease the incidence and severity of FES.

Analysis of Changes in Right Ventricular Systolic Function by Point-of-Care Ultrasound in Patients Undergoing Corrective Surgeries for Femur Fracture

Background:

Fat embolism syndrome (FES) following major orthopedic injuries and surgeries is a well-known phenomenon where acute depression of right ventricular (RV) systolic function is a potential possibility. Clinical presentation of FES may vary from mild self-limiting nature to severe life-threatening multiorgan dysfunction syndrome with pulmonary manifestations being most common.

Aims:

This study was aimed to know whether perioperative assessment of RV function by measuring tricuspid annular plane systolic excursion (TAPSE) with point-of-care transthoracic echocardiogram will identify patients at risk of developing FES and its sequelae.

Settings and Design:

This was a prospective observational study.

Materials and Methods:

This study was carried out in 142 patients with femur fractures posted for correction surgeries of both genders who require intramedullary (IM) reaming. TAPSE was recorded four times perioperatively. Time taken for IM reaming was also recorded.

Statistical Analysis Used:

Recorded data were analyzed using professional statistics package Epi Info 7.0 version for Windows. Descriptive data were represented as mean ± standard deviation for numeric variables, percentages, and proportions for categorical variables. Repeated-measure ANOVA was applied to assess the changes in TAPSE from baseline to immediate postoperative, after 6-h postoperative, and after 24-h postoperatively. Pearson's correlation was utilized to be applied to assess the relationship between TAPSE and other numerical variables.

Results:

All four readings of TAPSE were well above 17 mm (mean of 19.06, 19.05, 19.04, and 19.04, respectively). Mean reaming time was found to be 6.92 min. None of the patients developed any postoperative pulmonary complications.

Conclusion:

Assessment of RV function can be done with relative ease using TAPSE as a noninvasive method without any complications. Reaming time not exceeding 12 min did not produce any changes in RV function as measured by TAPSE as well as any postoperative pulmonary complications.

Fat embolism in right internal jugular vein: incidental ultrasound finding during internal jugular vein cannulation

Background

We report a case study of fat embolism seen on ultrasound at right internal jugular vein during central venous cannulation in a patient diagnosed with fat embolism syndrome. This case demonstrates the importance of ultrasound for evaluation of trauma cases with suspicion of fat embolism.

Case presentation

A 23-year-old trauma patient with closed fracture of left femoral shaft and left humerus presented to our emergency department (ED). 11 h after admission to ED, patient became confused, hypoxic and hypotensive. He was then intubated for respiratory failure and mechanically ventilated. Transesophageal ultrasound revealed hyperdynamic heart, dilated right ventricle with no regional wall abnormalities and no major aorta injuries. Whole-body computed tomography was normal. During central venous cannulation of right internal jugular vein (IJV), we found free floating mobile hyperechoic spots, located at the anterior part of the vein. A diagnosis of fat embolism syndrome later was made based on the clinical presentation of long bone fractures and fat globulin in the blood. Despite aggressive fluid resuscitation, patient was a non-responder and needed vasopressor infusion for persistent shock. Blood aspirated during cannulation from the IJV revealed a fat globule. Patient underwent uneventful orthopedic procedures and was discharged well on day 5 of admission.

Conclusions

Point-of-care ultrasound findings of fat embolism in central vein can facilitate and increase the suspicion of fat embolism syndrome.

Electronic supplementary material

The online version of this article (10.1186/s13089-019-0116-9) contains supplementary material, which is available to authorized users.

Effects of the ALX/FPR2 receptors of lipoxin A4 on lung injury induced by fat embolism syndrome in rats

This study was designed to investigate the inflammatory responses in fat embolism syndrome (FES) and the relationship of ALX/FPR2 receptors and lipoxin A₄ (LXA₄) in FES models. In this model, lung injury score, lung tissue wet-to-dry (W/D) ratio and total protein concentration in bronchoalveolar lavage fluid (BALF) were increased compared with those of the control group. Meanwhile, the number of leukocytes and neutrophils was significantly increased in the FES group, as was the myeloperoxidase (MPO) activity and mRNA expression. In addition, the release of TNF-α and IL-1β was increased. Then, we explored whether LXA₄ and ALX/FPR2 were involved in the pathological process of FES. The LXA₄ concentration in the experimental groups was markedly higher than that in the control group. At the same time, the protein and mRNA levels of ALX/FPR2 were upregulated in the rat model of FES. Moreover, rats treated with BML-111, an agonist for the ALX/FPR2 receptor of LXA₄, showed a lower inflammatory response than mice treated with fat alone. However, the role of BML-111 in fat emboli (FE)-induced acute lung injury (ALI) was attenuated by BOC-2, an antagonist of the ALX/FPR2 receptor of LXA₄. Our results demonstrated that the inflammatory response may play an important role in the pathogenesis of FES and that the activation of the ALX/FPR2 receptor for LXA₄ can decrease the inflammatory response and may be a therapeutic target for FE-induced ALI.

Fat Embolism Syndrome

Fat embolisms are fat globules that enter the circulatory system, typically through trauma, that may or may not lead to the development of fat embolism syndrome (FES), a rare and ill-defined diagnosis that can cause multiorgan failure and death. The exact mechanism of FES remains unknown, although several theories support the involvement of inflammatory response activation that contributes to characteristic clinical findings. There is no gold standard for diagnosis of FES, and treatment at this time remains primarily supportive. Early recognition of FES symptoms is the most beneficial nursing intervention for combating this serious disorder.

Is lipoxin A4 an effective treatment on fat embolism syndrome by attenuating pro-inflammatory response?

Fat embolism syndrome (FES) is characterized by high mortality and lack of effective treatment, the symptomatic therapy is most used to relieve clinical symptoms. Some studies have shown that inflammation is one of the main pathogeneses of FES. Lipoxin A4 is an endogenous-derived anti-inflammatory substance which was discovered recently. It can alleviate inflammatory response and promote inflammation resolution, and is referred as brake signal of inflammation. Therefore we hypothesize that lipoxin A4 may have a remission and therapeutic effect on FES by attenuating FES-induced inflammatory responses.

Rapamycin alleviated pulmonary injury induced by fat embolism syndrome in rats

Fat embolism syndrome (FES) is a serious complication after trauma, surgery and fat emulsion input and can lead to serious pulmonary injury. Autophagy controls the cell survival and homeostasis by removing the mis-folded proteins and damaged organelles as well as intracellular pathogens through a lysosomal degradation pathway. Increasing research documented that autophagy was wildly involved in variety of human diseases and had huge therapeutic potential. However, the role and mechanism of autophagy in FES remains largely unknown. The rat model of FES was established by tail vein injection with fat and was assessed by Wet-to-Dry (W/D) ratio analysis, hematoxylin-eosin (HE) analysis, staining Oil red staining analysis and qPCR analysis. Western blots were employed to detect the expression of autophagy markers. The changes of pulmonary injury were observed after premedication of rapamycin (an autophagy activator). The alveolar structural damage, red free fat substances in the blood vessels of lung, increased the lung ratio, and the up-regulated MPO expression and activity were showed in the FES models. The expressions of autophagy markers were decreased and meanwhile, apoptosis markers were increased in the FES model. Rapamycin restored the expression of autophagy markers and inhibited the apoptosis and further, resulting in the improvement of the pulmonary injury. Thus, our study demonstrated that autophagy was inhibited and apoptosis was promoted in FES and further Rapamycin alleviated the pulmonary damage in FES via restoring the autophagy and inhibiting the apoptosis.

Perioperative management of massive fat embolism syndrome presenting as refractory status epilepticus

Fat embolism syndrome (FES) most commonly can occur after trauma in patients with long bone fractures. While the majority of FES cases present as a mild decrease in mental status, some may manifest as seizure activity. We describe a case of a young patient with traumatic fractures who developed FES leading to refractory status epilepticus and simultaneously required damage controlled orthopedic surgery. The role of imaging modalities including magnetic resonance imaging, transcranial Doppler, and transesophageal echocardiography in diagnosis is discussed, and a multidisciplinary approach to successful perioperative management is described.

Correlation between the time elapsed after liposuction and the risk of fat embolism: An animal model

Background

Liposuction has become one of the most frequently performed procedures in the field of aesthetic surgery. Fat embolism syndrome after liposuction can easily be overlooked or underestimated; however, occasionally, fulminating fat embolism syndrome can develop and lead to a critical situation within 2–3 days after lipoplasty. Changes over time in the amount of circulating fat particles and the histology of major organs have not yet been studied.

Methods

This study was conducted using 18 male Sprague-Dawley rats aged 12 weeks and weighing 500–628 g (average, 562 g). Fifteen rats were used as the experimental group and 3 as the control group. Under general anesthesia, tumescent-technique liposuction was performed at the lateral flank areas and abdomen for 1 hour. Blood, lung, and brain tissue specimens were obtained at 1 hour, 1 day, and 2 days after the liposuction procedure.

Results

The average number of fat particles in the blood samples was 25,960/dL at 1 hour, 111,100/dL at 24 hours, and 21,780/dL at 48 hours. The differences between study groups were statistically significant. Both intravascular and extravascular fat particles with inflammation were seen in all 15 rats, as were inflammatory cell infiltration, hemorrhage, and consolidation with shrinkage of the lung alveoli.

Conclusions

These results imply that there is a strong possibility of fat embolism syndrome after liposuction in real clinical practice, and the first 24–48 hours after the operation were found to be the most important period for preventing pulmonary embolism and progression to fulminating fat embolism syndrome.

Neurological effects of fat embolism syndrome: A case report

Fat embolism syndrome is a serious multi-system pathology which classically affects the respiratory system, neurological system and causes a petechial rash. We present the case of a 20-year-old farmer who developed fat embolism syndrome following a traumatic femoral fracture. Features developed within 24 h of injury and necessitated a prolonged stay in Intensive Care. He exhibited significant signs of cerebral fat embolism syndrome including coma and seizures but went on to make full functional recovery. Magnetic resonance imaging is the recommended imaging modality for patients with suspected cerebral fat embolism. In this case, computerised tomography was inconclusive, but magnetic resonance imaging demonstrated the "starfield pattern" of multiple high signal foci on a dark background. Supportive treatment of fat embolism syndrome is required in an appropriate setting, such as High Dependency or Intensive Care, for patients at risk of hypoxia or neurological deterioration. Despite major neurological involvement of fat embolism syndrome, full recovery is described by several cases including ours.

Timing of definitive fixation of major long bone fractures: Can fat embolism syndrome be prevented?

Fat embolism is common in patients with major fractures, but leads to devastating consequences, named fat embolism syndrome (FES) in some. Despite advances in treatment strategies regarding the timing of definitive fixation of major fractures, FES still occurs in patients. In this overview, current literature is reviewed and optimal treatment strategies for patients with multiple traumatic injuries, including major fractures, are discussed. Considering the multifactorial etiology of FES, including mechanical and biochemical pathways, FES cannot be prevented in all patients. However, screening for symptoms of FES should be standard in the pre-operative work-up of these patients, prior to definitive fixation of major fractures.

Inhalational Ciclesonide found beneficial in prevention of fat embolism syndrome and improvement of hypoxia in isolated skeletal trauma victims

BACKGROUND

Many studies have established intravenous corticosteroid as an effective prophylactic therapy in fat embolism syndrome (FES). However, its use is limited among surgeons because of systemic side effects. Inhalational steroids have least systemic effects and are widely used for several chest conditions (i.e., asthma), but their effectiveness in FES has not been established.

QUESTION/PURPOSE

This study was sought to evaluate the (1) efficacy and (2) safety of inhalational Ciclesonide (CIC) in prevention of FES and treatment of hypoxemia in isolated skeletal trauma victims.

METHODS

A nonrandomized prospective control trial was designed in which all patients between 18 and 40 years with isolated skeletal injury who presented within 8 h of injury were allocated to either Trial group or control group. Trial group patients received 640 mcg of inhalational CIC with a metered-dose inhaler at the time of admission, and at 24 h. Control group patients did not receive any prophylactic therapy. Both groups were evaluated for development of FES (Gurd's criteria) and hypoxemia (PaO₂ <70 mmHg) for 72 h. The complications related to CIC administration were evaluated in trial group patients during their hospital stay.

RESULTS

Of 35 patients in each group, two patients in Trial group and nine patients in control group developed FES (P = 0.022). Eight patients in Trial group had hypoxemia at the time of admission, six of them improved and one additional patient developed hypoxemia after inhalational CIC administration. In control group, ten patients had hypoxia at the time of admission, only one of them improved and remaining nine patients had persistent hypoxemia even after 72 h. Additionally, three patients developed hypoxemia. A significant improvement in hypoxemia and a significant decrease in the incidence of FES were observed in Trial group (P < 0.05) compared to control group. None of the patients presented with any complications or adverse effects of steroid in Trial group.

CONCLUSION

Inhalational CIC is a safe and effective therapy for prevention of FES and also an effective drug for treatment of hypoxemia in orthopedic trauma victims.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Cortical blindness along with motor aphasia: An unusual presentation of fat embolism syndrome

Fat embolism syndrome presented with the classical triad of respiratory manifestations (95%), cerebral effects (60%) and Petechial rash (33%). Focal neurological symptoms in the form of combined bilateral cortical blindness and motor aphasia even prior to respiratory symptoms have been never reported in previous literature. We describe a case of these rare focal neurological symptoms secondary to the fat embolism syndrome in a young adult male following closed femur fracture.

Inflammatory responses to neutral fat and fatty acids in multiple organs in a rat model of fat embolism syndrome. Forensic Sci Int. 2015;254:126-132. [PMID: 26218407 DOI: 10.1016/j.forsciint.2015.07.011]

Fat embolism syndrome (FES) is a common complication of long bone fractures. FES is rare but with significant morbidity and occasional fatalities. Studies of animal models of FES are numerous; however, few studies compare inflammatory reactions in multiple organs. The present study investigated the effect of neutral fat and fatty acids, which cause changes in multiple organs and induce FES. Using rats we evaluated the ratio of lung-to-body weight and conducted histological analyses and quantitative analysis of inflammatory cytokine mRNAs in the lungs following intravenous administration of neutral fat or fatty acids. Neutral fat increased the ratio of lung-to-body weight, and neutral fat formed emboli in lung capillaries. The levels of interleukin-1 beta (IL-1β), IL-6 and tumor necrosis factor-alpha (TNF-α) in the lungs increased after injection of neutral fat and oleic acid. Analysis of the histologic changes revealed that the highest numbers of fat droplets, occluding the capillaries of the lungs, kidney, heart, and brain formed 12h after the injection of neutral fat and fat droplets gradually diminished 48h later. Fat droplets were not detected in any organs after the injection of oleic acid. IL-1β and TNF-α levels in the lungs were elevated 9-24h after the injection of neutral fat, although IL-6 levels peaked at 6h. After injection of oleic acid, peak levels of IL-1β, IL-6, and TNF-α were detected at 6h, and IL-6 again increased in all organs and plasma at 15h. Neutral fat, but not fatty acids, formed emboli in the capillaries of multiple organs. These findings suggest that neutral fat increased inflammatory cytokine levels by forming emboli in organ capillaries, particularly in the lungs, while oleic acid augmented inflammatory cytokine levels by stimulating endothelial cells of multiple organs.

Clinical effectiveness analysis of dextran 40 plus dexamethasone on the prevention of fat embolism syndrome

This study aims to investigate the clinical efficacy of Dextran 40 plus dexamethasone on the prevention of fat embolism syndrome (FES) in high-risk patients with long bone shaft fractures. According to the different preventive medication, a total of 1837 cases of long bone shaft fracture patients with injury severity score (ISS) > 16 were divided into four groups: dextran plus dexamethasone group, dextran group, dexamethasone group and control group. The morbidity and mortality of FES in each group were analyzed with pairwise comparison analysis. There were totally 17 cases of FES and 1 case died. The morbidity of FES was 0.33% in dextran plus dexamethasone group and significantly lowers than that of other groups (P < 0.05). There was no significant difference among other groups (P > 0.05). Conclusion from our data is dextran 40 plus dexamethasone can effectively prevent long bone shaft fractures occurring in high-risk patients with FES.

Early, reliable, utilitarian predictive factors for fat embolism syndrome in polytrauma patients

BACKGROUND

Fat embolism is one of the apocalyptic pulmonary complications following high energy trauma situations. Since delay in diagnosis may have devastating consequences, early, easily accessible and relatively inexpensive investigations for risk stratification may prove useful, especially in developing nations.

MATERIALS AND METHODS

This prospective trial included a total of 67 young polytrauma patients, in whom the role of nine easily available, rapidly performable clinical or laboratory investigations (or observations noted at admission) in predicting the later occurrence of fat embolism syndrome were assessed. All the patients also underwent continuous monitoring of oxygen saturation with pulsoximetry.

RESULTS

The correlation between initial serum lactate (within 12 hours of injury) and hypoxia was statistically significant. There was a trend towards correlation with FES(by Gurd's criteria) (P=0.07), Sensitivity of 24-hour monitoring of oxygen saturation in predicting later pulmonary deterioration approached 100%.

CONCLUSIONS

The combination of three factors including polytrauma (with NISS >17), serum lactate >22 mmol/l at admission (within 12 hours of injury) fall in oxygen saturation (SaO2 below 90% in the initial 24 hours) predict the development of post-traumatic pulmonary complications, especially the fat embolism syndrome.

Pulmonary and cerebral fat embolism syndrome after total knee replacement

Fat embolism occurs after long bone fracture or orthopedic surgery and usually shows mild symptom. But it rarely results in fat embolism syndrome, presenting as multiorgan dysfunction such as lung, brain and skin. Although the diagnosis of fat embolism syndrome is mostly based on clinical features, we experienced fat embolism syndrome involving lung and brain, showing typical imaging findings in pulmonary computed tomography and brain magnetic resonance image. So we present interesting case about fat embolism syndrome after total knee replacement with reviewing associated literatures including imaging findings.

Fat embolism syndrome: clinical and imaging considerations: case report and review of literature

Fat embolism syndrome (FES) is a serious clinical disorder occurring after trauma, orthopedic procedures and rarely in non-traumatic patients. Fat emboli develop in nearly all patients with bone fractures, but they are usually asymptomatic. Small number of patients develop signs and symptoms of various organ system dysfunction due to either mechanical obstruction of capillaries by fat emboli or due to hydrolysis of fat to fatty acids. A triad of lung, brain and skin involvement develop after an asymptomatic period of 24 to 72 hours. This symptom complex is called FES. The incidence reported is up to 30%, but many mild cases may recover unnoticed. Diagnosis of fat embolism is clinical with nonspecific, insensitive diagnostic test results. Treatment of fat embolism syndrome remains supportive and in most cases can be prevented by early fixation of large bone factures. Here we report two cases of traumatic fat embolism, which were diagnosed initially by Gurd's criteria and subsequently confirmed by typical appearance on magnetic resonance imaging (MRI) of the brain in these patients. These patients were successfully treated with supportive management. In conclusion, diagnosis of FES needs high index of suspicion, exclusion of other conditions and use of clinical criteria in combination with imaging. Magnetic resonance imaging of the brain is of great importance in diagnosis and management of these patients.