Fat embolism

Trends and associated outcomes of fat embolism after trauma surgery

BACKGROUND

Fat embolism is a life-threatening complication often occurring in patients with traumatic injuries. However, temporal trends and perioperative outcomes of fat embolism remain understudied. Using a nationally representative cohort, we aimed to characterize temporal trends of fat embolism and its associated resource utilization in operatively managed trauma patients.

METHODS

All patients (≥18 years) undergoing any major operations after traumatic injuries were tabulated using the 2005 to 2020 National Inpatient Sample. Patients were stratified into those with fat embolism and those without. Multivariable logistic and linear regressions were developed to assess the association between fat embolism and outcomes of interest.

RESULTS

Of an estimated 10,600,000 hospitalizations, 7,479 (0.07%) patients had fat embolism. Compared to the non-fat embolism cohort, the fat embolism cohort was younger (55 [26-79] vs 69 [49-82] years, standard mean difference = 0.46) and more likely to receive treatment at a high-volume trauma center (42.9 vs 33.7%, standard mean difference = 0.19). Over the study period, there was an increase in annual mortality and hospitalization costs among the fat embolism group (nptrend <0.001). After risk adjustment, fat embolism was associated with greater odds of mortality (adjusted odds ratio: 2.65, 95% confidence interval: 2.24-3.14) compared to others. Additionally, fat embolism was associated with increased odds of cerebrovascular, infectious, and renal complications.

CONCLUSION

Among all operatively managed trauma patients, those who developed fat embolism had increased mortality, rates of complications, length of stay, and costs. Optimization of early and accurate identification of fat embolism is warranted to mitigate complications and improve resource allocation among trauma patients.

Fat intravasation, fat emboli and fat embolism syndrome in adult major trauma patients with intraosseous catheters: a systematic review

INTRODUCTION

Intraosseous (IO) administration of medication, fluids and blood products is accepted practice for critically injured patients in whom intravenous access is not immediately available. However, there are concerns that high intramedullary pressures resulting from IO infusion may cause bone marrow intravasation and subsequent fat embolisation. The aim of this systematic review is to synthesise the existing evidence describing fat intravasation, fat embolism and fat embolism syndrome (FES) following IO infusion.

METHODS

A systematic search of CINAHL, MEDLINE and Embase was undertaken using the search terms "intraosseous", "fat embolism", "fat intravasation" and "fat embolism syndrome". Two authors independently screened abstracts and full texts, against eligibility criteria and assessed risk of bias. A grey literature search (including references) was undertaken. Inclusion criteria were: all human and animal studies reporting novel data on IO-associated fat emboli. This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis.

RESULTS

22 papers were identified from the search, with a further 5 found from reference lists. N=7 full papers met inclusion criteria. These papers were all translational animal studies. The overall risk of bias was high. Studies demonstrated that fat intravasation and fat embolisation are near universal after IO infusion, but of uncertain clinical significance. The initial IO flush appears to cause the highest intramedullary pressure and highest chance of fat intravasation and embolisation. No conclusions could be drawn on FES.

CONCLUSIONS

IO catheters remain a useful intervention in the armamentarium of trauma clinicians. Although their use is widely accepted, there is a paucity of evidence investigating fat embolisation in IO infusions. Despite this, pulmonary fat emboli after IO infusion are very common. The existing data are of low quality with a high risk of bias. More research is needed to address this important subject.

PROSPERO REGISTRATION NUMBER

CRD42023399333.

CT pulmonary arteriogram diagnosis of macroscopic fat embolism to the lung

Pulmonary fat embolism (PFE) is a recognised complication of long bone fractures. The majority of cases represent microscopic embolism and are not detectable at CT pulmonary arteriography (CTPA). CT can be used to detect macroscopic fat based on Hounsfield attenuation. This case describes a case of macroscopic fat embolism to the pulmonary arteries which was confidently diagnosed at CTPA. Distinction from thromboembolism is important as treatment is supportive and may avoid risks of anticoagulation.

A 17-Year-Old Male With Hypoxemia After Long-Bone Fracture

CASE PRESENTATION

An otherwise healthy 17-year-old male patient presented to a periphery hospital with a compound fracture of the right distal tibia and fibula after a traumatic accident on a ski trip. He was treated empirically with IV cefazolin before undergoing open reduction with internal fixation with intramedullary nail for surgical fixation. Postoperatively, he became febrile, tachypneic, and hypoxemic, requiring up to 6 L/min supplemental oxygen by nasal prongs. He reported mild chest discomfort but denied productive cough, hemoptysis, or calf tenderness. Because of nonresolving oxygen demands, on postoperative day (POD) 4, he was transferred to a tertiary care center for further management.

A Rare Case of Progressive Encephalopathy in a Sickle Cell Trait Patient: A Case Report

Fat embolism syndrome (FES) is one of the underdiagnosed and underrecognized complications that can happen in multiple medical and surgical conditions. FES can manifest in a broad spectrum of signs and symptoms and affect multiple organ systems in the human body. One of the most commonly involved is the central nervous system (CNS), mainly the brain, which can be involved in different ways, and the presenting symptoms can vary in type and severity. One of the most common causes of FES is trauma, mainly a long bone fracture or any orthopedic injury. However, one of the rare causes of FES is sickle cell disease (SCD) and thalassemia. Generalized and vague presenting symptoms, the rarity of FES, and the absence of well-defined diagnostic criteria make it a challenging diagnosis for healthcare practitioners. FES diagnosis is usually made after having a high index of suspicion in patients with underlying risk factors that can precipitate and contribute to the pathophysiology of FES. Moreover, the diagnosis is usually reached after excluding other more common and treatable conditions.

Fat Pulmonary Embolism With Crazy-Paving Pattern Opacities and Pneumothorax: A Rare Complication of Liposuction

Fat embolism syndrome (FES) is a rare multiorgan disease caused by microvascular obstruction by fat globules and free fatty acid-mediated endothelial injury leading to pro-inflammatory cytokine release. We present a rare case of a 54-year-old woman who underwent elective aesthetic liposuction and developed FES and pneumothorax within 12 hours of the procedure.

Stars from the bones-An uncommon presentation of fat embolism syndrome

Trauma or surgery to the lower limbs can cause fat from the marrow within the leg bones to enter the bloodstream and form an embolus. However, if there is cerebral involvement without any pulmonary or dermatological manifestations at diagnosis, it could delay identifying cerebral fat embolism (CFE).

Prospective study examining the probability of cerebral fat embolism based on magnetic resonance imaging

Purpose

Cerebral fat embolism (CFE) is a rare syndrome caused by the embolization of fat particles into the brain circulation. This prospective single-center observational study investigated the incidence of CFE in long-bone or pelvic fractures based on magnetic resonance imaging (MRI) findings. The purpose of this study was to investigate the incidence of CFE by MRI findings with or without symptoms suggestive of CFE.

Methods

Eligible patients were consecutive, aged 15 years or older, with high-energy traumas, including pelvic or femur fractures. Excluded patients were those who died, could not undergo MRI resulting from medical conditions, or had insufficient mental capacity and no consultee to provide consent. The MRI was scheduled within 4 weeks of the injury, and the images were reviewed by one of the three neuroradiologists who were unaware of the patient's clinical information. Patient data regarding demographics, preceding trauma, injury severity score (ISS), presentation and examination timing of MRI, management including surgery, and outcome were collected.

Results

Sixty-two patients were recruited, and three patients were excluded. All patients were injured by blunt trauma. The median patient age was 44 years. The median ISS was 13, and 53 patients needed surgical fixation. There were 22 patients with long-bone fractures, all of whom received external fixation or intramedullary nailing on admission day. MRI was performed after a median hospital day of 18 days. Using MRI imaging, three (5.0%) patients were diagnosed with CFE, and three patients were suspected of CFE.

Conclusions

This is the first study to prospectively examine the probability of CFE based on MRI. Since fat embolism syndrome (FES) is confirmed in patients without clinical symptoms, CFE may be more common in patients with trauma than currently believed. Therefore, studies to determine the diagnostic criteria combined with symptoms, MRI, or other objective findings are required in the future.

Fat Embolism Syndrome After Knee Arthroscopy in a Pediatric Patient

Fat embolism syndrome describes a constellation of symptoms that follow an insult and that results in a triad of respiratory distress, neurologic symptoms, and petechia. The antecedent insult usually entails trauma or orthopedic procedure, most frequently involving long bone (especially the femur) and pelvic fractures. The underlying mechanism of injury remains unknown but entails biphasic vascular injury with vascular obstruction from fat emboli followed by an inflammatory response. We present an unusual case of a pediatric patient with acute onset of altered mental status, respiratory distress, hypoxemia, and subsequent retinal vascular occlusions after knee arthroscopy and lysis of adhesions. Diagnostic findings most supportive of the fat embolism syndrome included anemia, thrombocytopenia, pulmonary parenchymal, and cerebral pathologic findings on imaging studies. This case highlights the importance of fat embolism syndrome as a diagnostic consideration after an orthopedic procedure, even absent major trauma or long bone fracture.

Mortality Rates and autopsy findings in fat embolism syndrome complicating sickle cell disease

Fat embolism syndrome is a rare but underdiagnosed complication of sickle cell disease associated with high morbidity and mortality. It affects predominantly patients with a previously mild course of their illness and those of non-SS genotypes while there is possibly an association with infection with human parvovirus B19 (HPV B19). Here, we present the mortality rates and autopsy findings of all reported cases to date. A systematic review has revealed 99 published cases in the world literature with a mortality rate of 46%. Mortality varied greatly according to the time of reported cases with no survivors in the 1940s, 1950s or 1960s and no deaths since 2020. 35% of cases had previously undiagnosed sickle cell disease and the latter was only identified at autopsy after developing fat embolism with a fatal outcome. 20% of cases reported after 1986 tested positive for HPV B19 with an associated mortality of 63% whereas in cases that have not documented HPV B19 infection the mortality was 32%. The organs most often staining positive for fat were the kidneys, lungs, brain and heart whereas ectopic haematopoietic tissue was found in 45% of the examined lung specimens.

Multisystemic involvement of post-traumatic fat embolism at a Pediatric Trauma Center: a clinical series and literature review

Post-traumatic fat embolism syndrome (FES) is a severe complication consequent to bone fractures. The authors describe its clinical features and management in a population of teenagers by detailing demographics, organ involvement, laboratory, and imaging findings, as well as outcome. Moreover, a systematic review of pediatric published case reports of post-traumatic FES is provided. First, a series of eight episodes of post-traumatic FES that occurred in seven patients (median age 16.0 years, IQR 16.0-17.5) admitted to a pediatric intensive care unit (PICU) in an 8-year period was analyzed through a retrospective chart review. Secondly, a systematic research was performed on PUBMED database. Trauma patients ≤ 18 years without comorbidities in a 20-year period (2002-2022) were included in the review. Neurological impairment was present in five out of seven patients, and a patent foramen ovale was found in four cases. Hemodynamic instability requiring vasoactive drugs was recorded in four patients. A severe form of acute respiratory distress syndrome (ARDS) occurred in five cases, with the evidence of hemorrhagic alveolitis in three of them. In the literature review, eighteen cases were examined. Most cases refer to adolescents (median age 17.0 years). More than half of patients experienced two or more long bone fractures (median: 2 fractures). Both respiratory and neurological impairment were common (77.8% and 83.3%, respectively). 88.9% of patients underwent invasive mechanical ventilation and 33.3% of them required vasoactive drugs support. Neurological sequelae were reported in 22.2% of patients.

CONCLUSION

Post-traumatic FES is an uncommon multi-faceted condition even in pediatric trauma patients, requiring a high level of suspicion. Prognosis of patients who receive prompt support in an intensive care setting is generally favorable.

WHAT IS KNOWN

•Post-traumatic fat embolism syndrome is a severe condition complicating long bone or pelvic fractures. •Little is known about clinical features and management in pediatric age.

WHAT IS NEW

•Post-traumatic fat embolism syndrome can cause multiple organ failure, often requiring an intensive care management. •Prompt supportive care contributes to a favorable prognosis.

Nontrombotic Pulmonary Embolism: Different Etiology, Same Significant Consequences

Nontrombotic pulmonary embolism represents the embolization of different types of materials (cells, organisms, gas, foreign material) into pulmonary circulation. The disease is uncommon, and clinical presentation together with laboratory findings are nonspecific. Its pathology is usually misdiagnosed based on imaging findings as pulmonary thromboembolism, but the correct diagnosis is essential because different therapeutic approaches are required. In this context, knowledge of the risk factors associated with nontrombotic pulmonary embolism and specific clinical symptoms is fundamental. Our objective was to discuss the specific features of the most common etiologies of nontrombotic pulmonary embolism, gas, fat, amniotic fluid, sepsis and tumors, to provide assistance for a rapid and correct diagnosis. Because the most common etiologies are iatrogenic, knowledge of the risk factors could be an important tool for prevention or rapid treatment if the disease develops during different procedures. The diagnosis of nontrombotic pulmonary embolisms represent a laborious challenge, and endeavors should be made to prevent development and increase awareness of this disease.

Dyspnea after endomedullary nailing: Fat embolism

Fat embolism is a well-known and life-threatening condition that can develop after long bone fractures and lower limb orthopedic surgery. It presents in a wide range of respiratory, hematological, neurological, and cutaneous symptoms and signs of varying severity, resulting from embolic showering. It is important for clinicians to have a high index of suspicion for fat embolism in patients with respiratory compromise postoperatively. Rapid recognition and supportive treatment are key in improving the outcome of these patients. The prognosis is usually good, except in fulminant fat embolism syndrome.

Fat Embolism Syndrome Without Bone Fracture: Is It Possible?

BACKGROUND: Fat embolism syndrome is a life challenge syndrome. Early diagnosing and treatment can significantly improve the patient’s prognosis and likelihood of success. This syndrome occurs mainly after long bones fractures or orthopedic surgery up to 95% of diagnosed cases, but in unusual situation can be faced as well. These rare situations include diabetes mellitus, video-assisted thoracoscopies, fatty liver, and fat injection in plastic and cosmetic procedures. The likelihood of this syndrome can be increased if multiplex long bones fractures occur in the same patient simultaneously. This syndrome is usually manifested with respiratory changes (hypoxemia and ARDS), neurological focal symptoms (confusion, headache, aphasia, and hemiplegia), and skin abnormalities (petechias, and rush in conjunctiva and oral mucosa). The clinical scenario begins typically after 24−72 h of injury, and mainly, respiratory changes are the first, followed by neurological abnormalities and finally petechias as the most significant sign. CASE REPORT: In this case, we report a rare case of unexpected fat embolism syndrome after soft-tissue minimal trauma. This is the first case that we faced according to literature, and the aim of reporting this case is to emphasize that fat syndrome embolism can happen perhaps in every trauma patient even in minor soft-tissue trauma in absence of bone fractures. CONCLUSION: We strongly suggest that this case should make the physicians taking in consideration fat embolism syndrome even if bone fracture missed, to early diagnosing and adequately treating the patient, and optimizing his chances to survive.

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.

Rapid recovery of fat embolism syndrome with acute respiratory failure due to liposuction

Liposuction is not a risk-free procedure and potentially fatal complications may occur, especially liposuction-induced fat embolism syndrome (FES). Here we report the case of a 29-year-old woman who developed FES suddenly during a liposuction operation in a cosmetic medical clinic. She was transferred to the hospital and achieved complete recovery within 11 days by comprehensive therapeutic strategies, including noninvasive ventilation (NIV), corticosteroids, albumin, diuretics and anticoagulation. Liposuction-induced FES is a life-threatening condition, which can be treated with complate recovery by comprehensive therapeutic strategies according to its pathophysiologic mechanism.

Use of Point-of-Care Ultrasound and Focus-Assessed Transthoracic Echocardiography to Diagnose Acute Right Heart Failure Due to Fat Emboli in a Parturient

Fat embolism syndrome (FES), causing right heart dysfunction, is a rare disease that is often difficult to diagnose with imaging modalities such as computed tomography (CT). FES is the clinical presentation that follows the entry of fat globules into the systemic circulation, which typically results in respiratory failure, scattered petechiae, cardiovascular collapse, and neurological sequelae. It is mostly observed in the cases of orthopedic trauma but may occur in any circumstance where fat can enter the circulatory system. In this case report, the authors describe an atypical presentation of FES in a 24-week parturient. The use of bedside point-of-care ultrasonography (POCUS) and the focus-assessed transthoracic echocardiography (FATE) protocol aided in the prompt diagnosis of right heart failure and helped to confirm the diagnosis of FES with more advanced imaging technology.

Fat Embolism Syndrome and in-Hospital Mortality Rates According to Patient Age: A Large Nationwide Retrospective Study

Introduction

Fat embolism syndrome (FES) is a rare life-threatening condition that can develop after traumatic orthopedic injuries. Controversy remains concerning the epidemiology in the elderly population. Therefore, this study aims to report FES related to in-hospital mortality stratified by age.

Methods

A retrospective trauma cohort study was conducted using data from the National Trauma Data Bank (NTDB) from 2007 to 2014. All FES cases were included in the study with the diagnosis of FES (ICD9 958.1). Death on arrival cases were excluded. Patients were stratified by age cohort: less than 40 (G1), 40–64 (G2), and greater than 65 (G3) years of age. The primary outcome evaluated was in-hospital mortality. Multivariable regression models were performed to adjust for potential confounders.

Results

Between 2007 and 2014, 451 people from a total of 5,836,499 trauma patients in the NTDB met the inclusion criteria. The incidence rate was 8 out of 100,000. The inpatient mortality rate was 11.8% for all subjects with the highest mortality rate of 17.6% in patients over 65. Multivariable analyses demonstrated that age greater than 65 years was an independent predictor of mortality (aOR 24.16, 95% CI 3.73, 156.59, p=0.001), despite higher incidence and injury severity of FES among patients less than 40. No significant association with length of hospital stay, length of intensive unit care, or length of ventilation use was found between the groups. Subgroup analysis of the elderly population also showed a higher mortality rate for FES in femoral neck fracture patients (18%) than other femoral fractures (14%).

Conclusion

In this retrospective cohort analysis, old age (≥ 65 years) was found to be an independent risk factor for in-hospital mortality among fat embolism syndrome patients. Elderly patients specifically with femoral neck fractures should be monitored for the development of FES.

Concomitant post-traumatic ocular and cerebral fat embolism syndrome and thrombotic pulmonary embolism: A case report

RATIONALE

Fat embolism syndrome (FES) is composed of a triad of symptoms, including respiratory distress, neurologic deficit, and petechiae. Respiratory distress usually presents first before the other symptoms. Thrombotic pulmonary embolism (TPE) is a differential diagnosis of FES. Trauma is a risk factor for both diseases; however, co-occurrence is rare.

PATIENT CONCERNS

A 35-year-old male patient presented with altered consciousness, focal neurologic deficit, and respiratory distress after a left femoral subtrochanteric fracture and subsequent open reduction and internal fixation with an intramedullary nail.

DIAGNOSIS

Computed tomography pulmonary angiography (CTPA) revealed lower pulmonary artery filling defects and ground-glass opacities in bilateral lung, indicating TPE and FES, respectively.

INTERVENTIONS

Heparin was initially added and subsequently switched to apixaban. The symptoms improved quickly without major bleeding complications.

LESSION SUBSECTIONS

Concomitant TPE and FES after trauma are rare and require different treatment approaches. Due to clinical similarities, prompt chest CTPA was advised to detect TPE that was treated with anticoagulant therapy instead of supportive care for FES.

Factors Associated with Postoperative Lipiduria and Hypoxemia in Patients Undergoing Surgery for Orthopedic Fractures

We investigated factors associated with postoperative lipiduria and hypoxemia in patients undergoing surgery for orthopedic fractures. We enrolled patients who presented to our emergency department due to traumatic fractures between 2016 and 2017. We collected urine samples within 24 h after the patients had undergone surgery to determine the presence of lipiduria. Hypoxemia was defined as an SpO2 &lt;95% determined with a pulse oximeter during the hospitalization. Patients’ anthropometric data, medical history, and laboratory test results were collected from the electronic medical record. Logistic regression analyses were used to determine the associations of clinical factors with postoperative lipiduria and hypoxemia with multivariate adjustments. A total of 144 patients were analyzed (mean age 51.3 ± 22.9 years, male 50.7%). Diabetes (odd ratio 3.684, 95% CI, 1.256–10.810, p = 0.018) and operation time (odd ratio 1.005, 95% CI, 1.000–1.009, p = 0.029) were independently associated with postoperative lipiduria, while age (odd ratio 1.034, 95% CI, 1.003–1.066, p = 0.029), body mass index (odd ratio 1.100, 95% CI, 1.007–1.203, p = 0.035), and operation time (odd ratio 1.005, 95% CI, 1.000–1.010, p = 0.033) were independently associated with postoperative hypoxemia. We identified several factors independently associated with postoperative lipiduria and hypoxemia in patients with fracture undergoing surgical intervention. Operation time was associated with both postoperative lipiduria and hypoxemia, and we recommend that patients with prolonged operation for fractures should be carefully monitored for clinical signs related to fat embolism syndrome.

Fatal Fulminant Fat Embolism Syndrome in Adult Spine Deformity Surgery: A Case Report

CASE

A 68-year-old woman was scheduled to undergo elective correction of coronal spinal malalignment after a previous lumbar instrumented fusion. In the final stages of the operation, the patient became hemodynamically unstable. Her systemic condition worsened subsequently, leading to cardiac arrest followed by unsuccessful resuscitation. An autopsy revealed a massive fat embolism in the lungs.

CONCLUSIONS

The diagnosis of fat embolism syndrome (FES) is clinical, and treatment is supportive, with no clinical or investigative criteria that can facilitate diagnosis in a patient under general anesthesia. This is the first description of FES in adult spinal deformity surgery.

A Rare Case of Cerebral Fat Embolism With No Respiratory or Dermatologic Involvement

Fat embolism syndrome is potentially lethal. It is frequently a complication of long bone fractures and/or orthopedic surgery. Cerebral fat embolism is an unusual condition characterized by purely cerebral involvement. Neurological signs can be variable and brain MRI has a pivotal role in the diagnosis. We report the case of a 69-year-old male who presented motor impairment and a disorder of consciousness in the early postoperative course of total hip arthroplasty for a left femoral neck fracture, which occurred 24 hours before surgery. He had no dermatologic or respiratory signs. No respiratory or dermatologic signs were found. Blood samples showed moderate thrombopenia and hemolytic anemia. Multiple lesions were found on brain MRI. Diagnosis of cerebral fat embolism was established after ruling out differentials.

Biomimetic Nanomaterials Triggered Ferroptosis for Cancer Theranostics

Ferroptosis, as a recently discovered non-apoptotic programmed cell death with an iron-dependent form, has attracted great attention in the field of cancer nanomedicine. However, many ferroptosis-related nano-inducers encountered unexpected limitations such as immune exposure, low circulation time, and ineffective tumor targeting. Biomimetic nanomaterials possess some unique physicochemical properties which can achieve immune escape and effective tumor targeting. Especially, certain components of biomimetic nanomaterials can further enhance ferroptosis. Therefore, this review will provide a comprehensive overview on recent developments of biomimetic nanomaterials in ferroptosis-related cancer nanomedicine. First, the definition and character of ferroptosis and its current applications associated with chemotherapy, radiotherapy, and immunotherapy for enhancing cancer theranostics were briefly discussed. Subsequently, the advantages and limitations of some representative biomimetic nanomedicines, including biomembranes, proteins, amino acids, polyunsaturated fatty acids, and biomineralization-based ferroptosis nano-inducers, were further spotlighted. This review would therefore help the spectrum of advanced and novice researchers who are interested in this area to quickly zoom in the essential information and glean some provoking ideas to advance this subfield in cancer nanomedicine.

Delayed onset of fat embolus in the cerebral venous system after breast and hip augmentation: a case report

Background

Cerebral fat embolism (CFE) is a subtype of fat embolism syndrome which tends to cause ischemic cerebral infarction. Fat embolism in the cerebral venous system have not been reported. We hereby present a rare case of fat embolus formed in the cerebral venous system 10 days after cosmetic surgery, and describe our management of this patient.

Case presentation

A 26-year-old woman with the disturbance of consciousness and recurrent convulsions of the right upper extremity over a 21-h period was admitted to our hospital. The patient was initially diagnosed with haemorrhagic infarction, and cerebral venous thrombosis (CVT) was suspected based on computed tomography (CT). A diagnosis of CFE was confirmed based on surgical findings. Breast and hip augmentation performed 10 days ago was considered the underlying cause. Drug-induced hypothermia, low molecular weight heparin, atorvastatin, dexamethasone, piperacillin/tazobactam, valproic acid, and mannitol were applied. On hospital day 30, she was discharged with a Montreal Cognitive Assessment score of 25.

Conclusions

Fat embolism can occur in the cerebral venous system, and may mimic CVT symptoms rather than CFE symptoms. Early identification of the nature of the embolus is essential. The use of heparin may prevent secondary thrombus formation, and accelerate fat embolus decomposition.

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.

Supportive care of right ventricular failure due to fat embolism syndrome

Pulmonary fat embolism is a common phenomenon in cases of traumatic long bone fractures, with only a minority developing the more catastrophic Fat Embolism Syndrome (FES). Diagnosis is clinical and requires a high index of suspicion. Treatment remains under-investigated, with common interventions having low quality level-of-evidence and no mortality benefit. In severe cases, focus should be on supporting the failing right ventricle through use of inotropes, pulmonary vasodilators, and mechanical circulatory support. This requires a thorough understanding of the unique physiology through the pulmonary circulation.

•

Pulmonary fat embolism is a common phenomenon following long bone fracture. Only a minority develop the more serious complication Fat Embolism Syndrome (FES).

•

FES is a diagnosis of exclusion classically characterized by hypoxemia, altered mentation, and petechiae. Mortality is often a result of right ventricular (RV) failure.

•

The failing RV has unique physiology. Treatment focuses on supportive care through use of inotropes, pulmonary vasodilators, and mechanical circulatory devices.

Radiological features of pulmonary fat embolism in trauma patients: a case series

PURPOSE

Fat embolism syndrome (FES) is a rare complication in trauma patients (usually with long bone fractures) in which migrating medullary fat precipitates multiorgan dysfunction, classically presenting with dyspnoea, petechiae and neurocognitive dysfunction. Although this triad of symptoms is rare, it nonetheless aids diagnosis of pulmonary fat embolism (PuFE). Typical imaging features of PuFE are not established, although increasing use of CT pulmonary angiography (CTPA) in this cohort may provide important diagnostic information. We therefore conducted a case series of FES patients with CTPA imaging at a Level 1 Trauma Centre in Melbourne, Australia.

METHODS

Medical records and various radiological investigations including CTPA of consecutive patients diagnosed clinically with FES between 2006 and 2018, including demographics, injury and their progress during their admission, were reviewed.

RESULTS

Fifteen FES patients with retrievable CTPAs were included (mean age 31.2 years, range 17-69; 12 males [80%]). 93.3% had long bone fractures. CTPA was performed 2.00 ± 1.41 days post-admission. Review of these images showed pulmonary opacity in 14 (93.3%; ground-glass opacities in 9 [64.3%], alveolar opacities in 6 [42.9%]), interlobular septal thickening in 10 (66.7%), and pleural effusions in 7 (46.7%). Filling defects were identified in three (20%) CTPAs, with density measuring - 20HU to + 63HU. Ten patients (66.7%) had neuroimaging performed, with two patients demonstrating imaging findings consistent with cerebral fat emboli.

CONCLUSION

CTPA features of PuFE are variable, with ground-glass parenchymal changes and septal thickening most commonly seen. Filling defects were uncommon.

Arterial Fat Embolism in a Pediatric Patient with Femur Fracture: A Case Report

CASE

Here, we present the case of a pediatric polytrauma patient found to have lower extremity intra-arterial fat embolism causing ischemic necrosis and ultimately necessitating below-the-knee amputation.

CONCLUSION

Fat embolism, a common complication of long bone fractures in adults, can be associated with significant morbidity. Although rare, it should be considered among the possible etiologies for a pulseless limb after trauma. Early fracture stabilization may prevent fat embolism and fat embolism syndrome; however, there is no known definitive treatment, and management is supportive.

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.

Incidence of Fat Embolism Syndrome in Femur Fractures and Its Associated Risk Factors over Time-A Systematic Review

BACKGROUND

Fat embolism (FE) continues to be mentioned as a substantial complication following acute femur fractures. The aim of this systematic review was to test the hypotheses that the incidence of fat embolism syndrome (FES) has decreased since its description and that specific injury patterns predispose to its development.

MATERIALS AND METHODS

Data Sources: MEDLINE, Embase, PubMed, and Cochrane Central Register of Controlled Trials databases were searched for articles from 1 January 1960 to 31 December 2019.

STUDY SELECTION

Original articles that provide information on the rate of FES, associated femoral injury patterns, and therapeutic and diagnostic recommendations were included.

DATA EXTRACTION

Two authors independently extracted data using a predesigned form.

STATISTICS

Three different periods were separated based on the diagnostic and treatment changes: Group 1: 1 January 1960-12 December 1979, Group 2: 1 January 1980-1 December 1999, and Group 3: 1 January 2000-31 December 2019, chi-square test, χ² test for group comparisons of categorical variables, p-value < 0.05.

RESULTS

Fifteen articles were included (n = 3095 patients). The incidence of FES decreased over time (Group 1: 7.9%, Group 2: 4.8%, and Group 3: 1.7% (p < 0.001)). FES rate according to injury pattern: unilateral high-energy fractures (2.9%) had a significantly lower FES rate than pathological fractures (3.3%) and bilateral high-energy fractures (4.6%) (p < 0.001).

CONCLUSIONS

There has been a significant decrease in the incidence of FES over time. The injury pattern impacts the frequency of FES. The diagnostic and therapeutic approach to FES remains highly heterogenic to this day.

Radiologic mimics of pulmonary embolism

The diagnosis of pulmonary embolism (PE) is often made more challenging by the presence of diseases that can mimic thromboembolic disease. There is no specific or sensitive constellation of clinical signs or symptoms that can be used to diagnose PE. Ventilation/perfusion scans can have false-positive findings related to mediastinal conditions that can compress the pulmonary arteries, and pulmonary hemorrhage can resemble PE on V/Q scanning with potentially devastating consequences if anticoagulation is started. CT-scan related issues l eading to potential false-positive diagnoses range from inadequate imaging technique, to systemic-pulmonary shunting, to non-thrombotic occlusion of pulmonary arteries by tumor, septic emboli, and emboli of fat, air, and foreign material, as well as vasculitic processes. Careful assessment of the patient and consideration of these potential mimickers is imperative to correct diagnosis of this potentially life-threatening condition.

Personal Strategy to Avoid Fat Embolism During Fat Grafting: Brisk Withdrawal of Cannula While Injection

INTRODUCTION

Complications of fat grafting by means of injection may lead to unwanted passage of substrate into vessel lumens resulting in catastrophic complications. Likewise, a similar trend of complications is observed with non-autologous fillers regardless of an almost generalized use of blunt cannulas, the latter being implicated in the majority of serious vascular complications of hyaluronic acid injection. This report is the product of investigation to review all cases that underwent an original technique of fat injection: "The smart fat injection" during the cannula's brisk withdrawal technique. The aim of this research was to document the safety of this technique by searching if fat embolism had occurred and if yes, its incidence in this group of fat injection surgeries.

METHOD

This retrospective review included 3039 patients who underwent the smart fat injection at the facial or corporeal level between 2001 and 2019. The study focused on the search for complications linked to fat yet also cruorical embolism, as the latter may resemble the clinical symptoms of fat embolism.

RESULTS

The assessment of the 3039 patients who underwent the smart fat injection during cannula's brisk withdrawal, resulted in none presenting clinically detectable fat or a cruorical embolism.

CONCLUSION

This report documents the safety of the smart fat injection developed over a period of 22 years. It further explains the rationale of the technique for avoiding fat embolism while simultaneously enhancing fat take. This technique should not be implemented without appropriate in vitro training.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine Ratings, please refer to Table of Contents or online Instructions to Authors www.springer.com/00266 .

Safety of oil-based contrast medium for hysterosalpingography: a systematic review

Recent meta-analyses have shown that a hysterosalpingography (HSG) with oil-based contrast increases pregnancy rates in subfertile women. However, the frequency of complications during or after an HSG with oil-based contrast in subfertile women and/or their offspring is still unclear. This systematic review and meta-analysis, without restrictions on language, publication date or study design, was performed to fill this knowledge gap. The results show that the most frequently reported complication was intravasation of contrast, which occurred in 2.7% with the use of oil-based contrast (31 cohort studies and randomized controlled trials [RCT], 95% CI 1.7-3.8, absolute event rate 664/19,339), compared with 2.0% with the use of water-based contrast (8 cohort studies and RCT, 95% CI 1.2-3.0, absolute event rate 18/1006). In the cohort studies and RCT there were 18 women with an oil embolism (18/19,339 HSG), all without serious lasting consequences. Four cases with serious consequences of an oil embolism were described (retinal oil embolism [n = 1] and cerebral complaints [n = 3]); these reports did not describe the use of adequate fluoroscopy guidance during HSG. In conclusion, the most frequently reported complication after an HSG with oil-based contrast is intravasation occurring in 2.7%. In total four cases with serious consequences of oil embolisms in subfertile women were published.

Transient cortical blindness in fat embolism syndrome---a diagnostic enigma

Fat embolism syndrome (FES) is a serious life-threatening manifestation of the fat embolism phenomenon characterized by Bergman's triad of dyspnea, petechiae and mental confusion. While fat embolization into systemic circulation is common, FES occurs in a meagre 0.05%-3% of patients having isolated long bone fractures. Though visual symptoms are commonly attributed to fat embolism retinopathy and is a later occurrence, it may not always be the case. Cortical blindness has been seldom reported in association with FES, and less so as a presenting complaint. Furthermore, no previous literature has described the same in context of an isolated tibia fracture. We report a 20-year-old gentleman with an isolated right tibia shaft fracture who developed sudden onset diminution of vision in both eyes less than 24 h following trauma with no other complaints. Lack of any remarkable ophthalmoscopic findings or other symptoms left us with a diagnostic conundrum. He later went on to develop altered mentation, hypoxia and generalized tonic-clonic seizures with subsequent MRI revealing multiple cerebral fat emboli also involving both occipital lobes. Supportive measures were instituted and his general condition as well as vision gradually improved following which he underwent plate fixation of the fracture under spinal anaesthesia. The perioperative period was uneventful and he was discharged following staple removal. At one month of follow-up, the patient had no residual visual field defects or neurological deficits. Though FES is rare among isolated tibia fractures, this clinical catastrophe may strike in any unsuspected setting thereby warranting a high index of suspicion to ensure early diagnosis and improved patient outcomes.

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.

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.

Nontraumatic Multiple-Organ Fat Embolism: An Autopsy Case and Review of Literature

The patient was an 88-year-old woman with a 10-year history of hypertension. She was suspected to have been hit by a car. At the time of the event, she was conscious and able to stand on her own and had no obvious injuries. She was sent home, but she lapsed into unconsciousness and was nonresponsive after 2 hours. She was sent to the hospital, and her heartbeat and breathing stopped. After half an hour of rescue attempts, her heartbeat did not recover, and she was declared dead. During the autopsy, a small subcutaneous hemorrhage was observed below the right knee joint. No obvious internal organ injuries or bone fractures were observed. The deceased also had mild atherosclerosis in the coronary arteries and an old cerebral infarction in the right cerebellum. The tissue histopathological tests showed distinct fat embolism in multiple organs, including the brain, lungs, kidneys, liver, and pancreas. A postmortem blood biochemistry test of the heart blood showed that the levels of low-density lipoprotein, cholesterol, triglycerides, and free fatty acids in the blood were increased, and the level of C-reactive protein was elevated. According to the autopsy results, the direct cause of death was multiorgan fat embolism. This case suggests that aging, hypertension, and hyperlipidemia may be risk factors for nontraumatic fat embolism under stressful conditions.

Fat Embolism Syndrome in Sickle Cell Disease

Fat embolism syndrome is a devastating complication of sickle cell disease resulting from extensive bone marrow necrosis and associated with high mortality rates, while survivors often suffer severe neurological sequelae. Despite that, the syndrome remains under-recognised and under-diagnosed. Paradoxically, it affects exclusively patients with mild forms of sickle cell disease, predominantly HbSC and HbSβ⁺. A significant number of cases occur in the context of human parvovirus B19 infection. We provide here a brief summary of the existing literature and describe our experience treating 8 patients in our institution. One patient had HbSS, 6 HbSC and 1 HbSβ⁺. All patients developed type I respiratory failure and neurological involvement either at presentation or within the first 72 h. The most striking laboratory abnormality was a 100-fold increase of the serum ferritin from baseline. Seven patients received emergency red cell exchange and 1 simple transfusion. Two patients (25%) died, 2 patients (25%) suffered severe neurological impairment and 1 (12%) mild neurological impairment on discharge, while 3 (38%) patients made a complete recovery. With long-term follow-up, 1 patient with severe neurological impairment and one patient with mild neurological impairment made dramatic improvements, making the long-term complete recovery or near complete recovery rate 63%. Immediate red cell exchange transfusion can be lifesaving and should be instituted as soon as the syndrome is suspected. However, as the outcomes remain unsatisfactory despite the increasing use of red cell exchange, we suggest additional therapeutic measures such as therapeutic plasma exchange and pre-emptive transfusion for high risk patients.

Extremely Acute-Onset Cerebral Fat Embolism

Cerebral fat embolism (CFE) causes the neurological involvement observed in fat embolism syndrome, which is a post-traumatic complication seen mostly after long bone fractures and usually presents 24–72 h after the injury. An early 80s female who sustained an isolated traumatic fracture of the left distal femur without dislocation was alert on admission but fell into a coma 55 min after the injury. Brain computed tomography showed no abnormalities. Brain magnetic resonance imaging was performed approximately 5 h after the accident, and diffusion-weighted images revealed hyperintense, dot-like lesions disseminated in a “starfield” pattern in the brain. The patient was diagnosed with CFE and admitted to the intensive care unit. The day after the injury, the patient developed petechiae on the palpebral conjunctiva and was still comatose 4 months after the trauma. The current patient developing CFE in less than 1 h after a traumatic injury illustrates that CFE should be considered in patients with sudden deterioration of consciousness within 1 h after long bone fractures.

Risk Factors of Fat Embolism Syndrome After Trauma: A Nested Case-Control Study With the Use of a Nationwide Trauma Registry in Japan

BACKGROUND

Fat embolism syndrome (FES) is a rare syndrome resulting from a fat embolism, which is defined by the presence of fat globules in the pulmonary microcirculation; it is associated with a wide range of symptoms.

RESEARCH QUESTION

What are the specific unknown risk factors for FES after we have controlled for basic characteristics and patient's severity?

STUDY DESIGN AND METHODS

This was a nested case-control study that used the Japan Trauma Data Bank database from 2004 and 2017. We included patients with FES and identified patients without FES as control subjects using a propensity score matching. The primary outcome was the presence of FES during a hospital stay.

RESULTS

There were 209 (0.1%) patients with FES after trauma; they were compared with 2,090 matched patients from 168,835 candidates for this study. Patients with FES had long bone and open fractures in their extremities more frequently than those without FES. Regarding treatments, patients with FES received bone reduction and fixation more than those without FES. Among patients who received bone reduction and fixation, time to operation was not different between the groups (P = .63). The overall in-hospital mortality rate was 5.8% in patients with FES and 3.4% in those without FES (P = .11). Conditional logistic regression models to identify risk factors associated with FES shows long bone and open fractures in extremities injury were associated with FES. Primary bone reduction and fixation was not associated independently with FES (OR, 1.80; 95% CI, 0.92-3.54), but delay time to the operation was associated with FES (OR, 2.21; 95% CI, 1.16-4.23).

INTERPRETATION

Long bone and open fractures in injuries to the extremities were associated with FES. Although bone reduction and fixation were not associated with FES, delay time to the operation was associated with FES.

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.

The intersection of cerebral fat embolism syndrome and traumatic brain injury: a literature review and case series

OBJECTIVE

To review the historical, clinical, radiographic, and outcome characteristics of individuals diagnosed with an acquired brain injury (ABI) due to cerebral fat embolism syndrome (CFES) with and without features of traumatic brain injury (TBI).

METHODS

A retrospective chart review of individuals with the diagnosis of CFES admitted to an ABI rehabilitation program. Cases were divided into two cohorts 1) individuals with evidence of classic features of CFES alone, and 2) individuals with evidence of CFES in conjunction with features of TBI.

RESULTS

14 individuals were identified, seven individuals with diagnosis of CFES alone, and seven with CFES and TBI. Median initial GCS was 15 for the isolated CFES cohort and 8 for the dual diagnosis cohort (p =.006). There were clear qualitative differences in MRI findings with characteristic patterns between the two groups.

CONCLUSION

The diagnosis of CFES is an important consideration for individuals who have new neurologic impairment following a trauma, especially in cases where initial GCS was high. MRI has an important role in differentiating lesions of CFES from TBI and should be utilized for prognostication and management decisions. Individuals with neurologic injury secondary to CFES had good functional recovery outcomes as measured by Glasgow Outcome Scale.

Concomitant fat embolism syndrome and pulmonary embolism in a patient with patent foramen ovale

We present a rare case of a patient with concurrent fat embolism and pulmonary embolism, in a closed femur fracture with patent foramen ovale (PFO). A 24-year-old man was involved in a motor vehicle accident with a closed left midshaft femur fracture. He developed fat embolism syndrome (FES) on day 3 of admission, and plating was performed. The D-dimer concentration was also high, which raised the suspicion of pulmonary artery embolism. Computed tomography pulmonary angiography (CTPA) revealed right inferior lobar pulmonary artery embolism and FES. A transthoracic echocardiogram (TEE) was performed, which showed a PFO. The presence of a PFO in patients with pulmonary embolism increases the risk of systemic embolism. Therefore, we recommend the routine echocardiogram for patients with pulmonary embolism to exclude any cardiac defect in causing right-to-left shunts, which predisposes the patient to paradoxical embolism.