Fat embolism

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.

Unusual clinicopathological presentation of nontraumatic cerebral fat embolism: Two-case report

RATIONALE

Fat embolism syndrome (FES) is characterized by the classical triad of cerebral, respiratory, and cutaneous manifestations. In contrast, cerebral fat embolism (CFE), corresponding to incomplete pure type FES, is much rarer and usually follows trauma. CFE typically shows a "starfield" pattern on diffusion-weighted magnetic resonance imaging due to the involvement of multiple small arteries. We report 2 unusual cases of CFE that showed a nontraumatic etiology and the involvement of a single dominant cerebral artery.

PATIENT CONCERNS

Case 1 was a 33-year-old woman without a history of trauma who visited the emergency room due to hemiparesis and hemisensory deficits. She was a heavy smoker and had used oral contraceptives for several years. Most importantly, she had 2 experiences of autologous fat grafting 2 months previously. Magnetic resonance angiography (MRA) revealed acute occlusion of the right middle cerebral artery. Case 2 was an 80-year-old man suddenly presented with dizziness, ataxia, and left-sided sensorimotor dysfunction. He had a history of hypertension, untreated atrial fibrillation, and chronic alcoholism. MRA demonstrated the occlusion of the distal basilar artery.

DIAGNOSIS

Case 1: Microscopic findings demonstrated variable sized fat vacuoles intermixed with moderate amounts of thrombi. Case 2: Histologically, mature adipocytes were intermingled with fibrin, blood cells, and a fragment of entrapped soft tissue resembling the vessel wall.

INTERVENTION

Case 1 and 2 underwent aspirational thrombectomy guided by transfemoral cerebral angiography.

OUTCOME

Case 1 recovered well but Case 2 still suffers from gait ataxia.

LESSONS

CFE can rarely occur in various nontraumatic conditions, with or without evident etiology. Furthermore, it may not show characteristic clinicopathological manifestations. Therefore, careful follow up of those who have undergone procedures that are likely to trigger FES or who have hemodynamic or hypercoagulable risk factors is needed.

The Potential Role of Corticosteroid Prophylaxis for the Prevention of Microscopic Fat Embolism Syndrome in Gluteal Augmentations

BACKGROUND

Microscopic fat embolism syndrome (micro-FES) has been recently identified as a potentially fatal complication following gluteal augmentation utilizing autologous fat grafts; safety recommendations advocating for subcutaneous lipo-injections may be insufficient for its prevention.

OBJECTIVES

The authors of this systematic review evaluated the potential role of corticosteroid prophylaxis for the prevention of micro-FES in gluteal augmentation procedures.

METHODS

The authors performed a systematic search employing the National Library of Medicine (PubMed), Medline, and Embase databases. Search terms were those pertaining to studies reporting the efficacy of prophylactic corticosteroid administration on micro-FES incidence in a high-risk surrogate population.

RESULTS

Thirteen articles met the inclusion criteria for review, comprising 2 studies reporting on the efficacy of a single intravenous (IV) corticosteroid dose for the prophylaxis of micro-FES, 9 studies reporting on multiple prophylactic IV doses, and 2 additional studies reporting on the efficacy of inhaled corticosteroids in this context. All studies were identified from the orthopedic literature given that none were available directly from within plastic surgery. The prophylactic efficacy of multiple IV doses of methylprednisolone, or a single larger dose, was established, whereas the efficacy of inhaled corticosteroids remains elusive.

CONCLUSIONS

A single perioperative IV dose of methylprednisolone may be most appropriate for utilization by plastic surgeons; the safety and implication of this therapy on wound healing and fat graft survival are discussed. Further studies directly evaluating the efficacy of corticosteroid prophylaxis in the gluteal augmentation population are indicated. Finally, recommendations pertaining to the prevention, timely recognition, and effective management of micro-FES are discussed.

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.

A young adult with post-traumatic breathlessness, unconsciousness and rash

A 23-year-old Bangladeshi male was referred to our hospital for gradual worsening of breathlessness over 3 h, developed following a road-accident about 14 h previously. He had a close fracture of mid-shaft of his right tibia, which was immobilised with back slab at the previous healthcare facility. During presentation at the emergency department, he was conscious and oriented (Glasgow coma scale 15/15), tachycardic (heart rate 132 per min), blood pressure 100/70 mmHg, tachypnoeic (respiratory rate 34 per min) with oxygen saturation 89% on room air, and afebrile. Chest examination revealed restricted chest movement, hyper-resonant percussion notes and reduced breath sound on the left, and diffuse crackles on both sides.

Can you diagnose this young adult with post-traumatic breathlessness, unconsciousness and rash?http://bit.ly/2LlpkiV

Induction of periosteal bone formation by intraosseous BMP-2 injection in a mouse model of osteogenesis imperfecta

PURPOSE

Surgical interventions are routinely performed on children with osteogenesis imperfecta (OI) to stabilize long bones, often post fracture. We speculated that a combination of intramedullary reaming and intraosseous injection of recombinant bone morphogenetic protein-2 (BMP-2) could enhance periosteal ossification and ultimately cortical thickness and strength. This approach was conceptually tested in a preclinical model of genetic bone fragility.

METHODS

Six experimental groups were tested including no treatment, intramedullary reaming, and reaming with 5 µg BMP-2 injection performed in the tibiae of both wild type (WT) and Col1a2 ^G610C/+ (OI, Amish mutation) mice. Bone formation was examined at a two-week time point in ex vivo specimens by micro-computed tomography (microCT) analysis and histomorphometry with a dynamic bone label.

RESULTS

MicroCT data illustrated increases in tibial cortical thickness with intramedullary reaming alone (Saline) and reaming plus BMP-2 injection (BMP-2) compared to no intervention controls. In the OI mice, the periosteal bone increase was not statistically significant with Saline but there was an increase of +192% (p = 0.053) with BMP-2 injection. Dynamic histomorphometry on calcein label was used to quantify new woven bone formation; while BMP-2 induced greater bone formation than Saline, the anabolic response was blunted overall in the OI groups.

CONCLUSIONS

These data indicate that targeting the intramedullary compartment via reaming and intraosseous BMP-2 delivery can lead to gains in cortical bone parameters. It is suggested that the next step is to validate safety and functional improvements in a clinical OI setting.

Fatal diffuse pulmonary fat microemboli following reperfusion in liver transplantation with the use of marginal steatotic allografts

Organ shortage is a major cause of delayed liver transplantation and increased waitlist time. The level of donor steatosis is a significant determinant in organ selection. Scarcity of organs has led some programs to expand their acceptable criteria for the percentage of steatosis. We report two cases of liver transplantation of steatotic donor organs that resulted in mortality within hours from transplantation. Postmortem analysis showed evidence of diffuse pulmonary fat microemboli likely originating from the donor organ, with marked preservation reperfusion injury. The mechanism of diffuse fat microemboli in this setting and possible relationship to other perioperative syndromes (transfusion-related lung injury, acute kidney injury, and postreperfusion syndrome) is discussed.

Fat Embolism, Fat Embolism Syndrome and the Autopsy

Fat embolism is common following trauma and is a common autopsy finding in these cases. It may also be seen in non-traumatic cases and is seen in children as well as adults. In comparison fat embolism syndrome (FES) only occurs in a small number of trauma and non-trauma cases. Clinical diagnosis is based on characteristic clinical and laboratory findings. Fat embolism exerts its effect by mechanical blockage of vessels and/or by biochemical means including breakdown of fat to free fatty acids causing an inflammatory response. Fat embolism can be identified at autopsy on microscopy of the lungs using fat stains conducted on frozen tissue, including on formalin fixed but not processed tissue. With FES fat emboli can be seen in other organs including the brain, kidney and myocardium. Fat can also be identified with post-fixation staining, typically with osmium tetroxide. Scoring systems have been developed to try and determine the severity of fat embolism in lung tissue. Fat embolism is also common following resuscitation. When no resuscitation has taken place, the presence of fat on lung histology has been used as proof of vitality. Diagnosis of fat embolism syndrome at autopsy requires analysis of the history, clinical and laboratory findings along with autopsy investigations to determine its relevance, but is an important diagnosis to make which is not always identified clinically. This paper reviews the history, clinical and laboratory findings and diagnosis of fat embolism and fat embolism syndrome at autopsy.

VEGF mediates fat embolism-induced acute lung injury via VEGF receptor 2 and the MAPK cascade

Fat embolism (FE) is a lethal medical emergency often caused by fracture of long bones and amputation of limbs. Vascular endothelial growth factor (VEGF) promotes angiogenesis and increases vascular permeability. We tested the hypothesis that VEGF plays a critical role in FE-induced acute respiratory distress syndrome (ARDS) and acute lung injury (ALI). Fat tissues were collected from male Sprague-Dawley rats, and animal oil was extracted and mixed with water to form fatty micelles. The micelles were then injected into the tail vein to produce FE and ALI in rats. Lung weight gain was measured as the index of pulmonary edema. The expression of pulmonary VEGF was evaluated by real-time PCR and western blot analysis. Inducible nitric oxide synthase (iNOS) and phosphorylation of mitogen-activated protein kinase (MAPK) were determined by western blot analyses. Interleukin-1β (IL-1β) was quantified by ELISAs. Hematoxylin and eosin staining was used to evaluate the pathological damage of ALI. In this study, we found that animal oil-induced FE significantly increased pulmonary VEGF expression and MAPK phosphorylation. We also evaluated the inflammatory response after FE and found that iNOS and IL-1β significantly increased after FE. Systemic administration of SU-1498, an antagonist of VEGF receptor 2 (VEGFR-2), significantly attenuated the FE-induced inflammatory response and histological damage. This study suggested that VEGF is involved in FE-induced ARDS via the VEGFR-2 and MAPK cascades, which induce IL-1β release and iNOS upregulation. Blockade of could be used to treat FE-induced pulmonary damage.

Histopathological evaluation of autopsy cases with isolated pulmonary fat embolism (IPFE): is cardiopulmonary resuscitation a main cause of death in IPFE?

Background: Fat embolism (FE) may develop following many traumatic and atraumatic clinical conditions; however, fewer data exist regarding the occurrence of isolated pulmonary FE (IPFE). Cardiopulmonary resuscitation (CPR) is an emergency procedure for maintaining blood circulation and oxygenation during cardiac arrest. In this study, we aimed to evaluate the association of CPR with IPFE in autopsy cases.

Methods: A total 402 cases among 4,118 autopsies were diagnosed with IPFE, and the medical background of these cases was retrospectively evaluated. Diagnosis of FE and FE grading were performed with histopathological examinations of postmortem tissue samples, and injury-severity scores of traumatic cases were assessed. Data of traumatic and atraumatic cases were statistically compared.

Results: Of the IPFE cases, 298 (741%) were male and 104 (25.9%) female, with overall mean age 53.7 (2–99) years. Causes of death of studied subjects were traumatic for 302 (75.1%) and atraumatic reasons for 100 (24.9%) cases. CPR was performed for 277 cases of which 177 (63.9%) were traumatic and 100 (36.1%) were non-traumatic. In comparison to traumatic cases, significantly higher CPR frequency was determined in atraumatic IPFE (P=0.001). High grade FE in the traumatic cases, and mild-moderate grade of FE in the nontraumatic cases were found statistically significant (P=0.001).

Conclusion: This study indicates that CPR may be one of the leading factors in the development of IPFE in atraumatic conditions, and this procedure was related to mild–moderate IPFE manifestations. Regardless of whether conditions were traumatic or atraumatic, in patients who survive following CPR for manifest ventilation/perfusion problems, it should be remembered that IPFE may have developed due to CPR.

Intraluminal Arterial Filling Defects Misdiagnosed as Pulmonary Emboli: What Else Could They Be?

Pulmonary artery filling defects can be observed in various pathologic processes other than pulmonary embolism, for example, nonthrombotic pulmonary embolism with biological and nonbiological materials and intrinsic pulmonary artery lesions. They have also been described in rare conditions, such as fibrosing mediastinitis and congenital absence or stenosis of pulmonary artery, and some pulmonary parenchymal and airway malignancies. Misdiagnosis is common owing to the relative rarity of these conditions. Correct diagnosis is based on the appropriate clinical suspicion considering the unique clinical features, laboratory findings, and additional radiologic clues inferring a pathology other than pulmonary embolism.

Fat Embolism and Fat Embolism Syndrome

Fat embolism (FE) occurs frequently after trauma and during orthopaedic procedures involving manipulation of intramedullary contents. Classically characterized as a triad of pulmonary distress, neurologic symptoms, and petechial rash, the clinical entity of FE syndrome is much less common. Both mechanical and biochemical pathophysiologic theories have been proposed with contributions of vascular obstruction and the inflammatory response to embolized fat and trauma. Recent studies have described the relationship of embolized marrow fat with deep venous thrombosis and postsurgical cognitive decline, but without clear treatment strategies. Because treatment is primarily supportive, our focus must be on prevention. In trauma, early fracture stabilization decreases the rate of FE syndrome; however, questions remain regarding the effect of reaming and management of bilateral femur fractures. In arthroplasty, computer navigation and alternative cementation techniques decrease fat embolization, although the clinical implications of these techniques are currently unclear, illustrating the need for ongoing education and research with an aim toward prevention.

Approaching pulmonary fat embolism on postmortem computed tomography

PURPOSE

Pulmonary fat embolism (PFE) is a relevant diagnosis playing a role as a sign of vitality or a cause of death. Its severity is assessed according to histological grading systems like that of Falzi. The aim of this study was to determine the utility of unenhanced postmortem computed tomography (PMCT) for PFE diagnosis based on the detection of fat layers.

METHODS

Consecutive cases with PMCT and autopsy were studied retrospectively. The case group consisted of cases with positive PFE, and the control group included cases with negative PFE. Three observers independently assessed PMCT data for fat layers in the pulmonary trunk and the right and left pulmonary artery. For cases with fat layers, autopsy protocols were assessed for the cause of death, relation to trauma, and undertaken resuscitation measures.

RESULTS

Eight hundred thirty cases were included: 366 PFE positive cases (144 of Falzi grade 1, 63 of 1.5, 99 of 2, 28 of 2.5, and 32 of 3) and 464 PFE negative cases. Interrater reliabilities varied between substantial and almost perfect, and discrepancies were solved according to majority. Eighteen cases showed fat layers on PMCT (2 controls-traumatic instantaneous deaths-, 16 PFE positive cases). PMCT showed low sensitivity but high specificity for PFE diagnosis. The layers were located at the same position in the pulmonary trunk directly adjacent to the pulmonary valve distal to the right ventricle.

CONCLUSION

Fat layer on PMCT is a rare finding but relates to PFE diagnosis, especially of severe histological grade. It is to be expected in a typical position within the pulmonary trunk.

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.

Microscopic and Macroscopic Fat Embolism: Solving the Puzzle with Case Reports

BACKGROUND

The frequency of fat embolism mortality after liposuction has increased. As the only dependable evidence for this problem is that available in the medical literature, a study of clinical case reports is warranted.

METHODS

The authors reviewed the medical literature by searching for case reports of fat embolism after liposuction in humans who manifested either of the variants of the condition: microscopic fat embolism or macroscopic fat embolism. The authors performed a literature search of the PubMed and PubMed Central databases from the first case of fat embolism syndrome associated with liposuction reported until March of 2017; keywords Fat Embolism (Fat Embolism Syndrome), Liposuction, and Case (((fat embolism) AND liposuction) AND case) were used. A detailed analysis of the data contained in the clinical case reports was conducted.

RESULTS

In total, 39 and 98 articles were found in PubMed and PubMed Central, respectively, using the keywords (((Fat + Embolism) + AND + Liposuction) + AND + Case). After analysis, only 15 reports corresponded to cases of macroscopic or microscopic fat embolism after liposuction, and the basic statistics of the two proposed variants were examined.

CONCLUSIONS

This work provides relevant information regarding very important characteristics of microscopic and macroscopic fat embolism. Despite the diagnostic difficulty, clinical diagnosis remains the gold standard for identifying microscopic and macroscopic fat embolism. The establishment of a rapid and timely diagnosis is of great help for appropriate treatment.

Fat Embolism and Nonconvulsive Status Epilepticus

Fat embolism syndrome (FES) typically occurs following orthopedic trauma and may present with altered mental status and even coma. Nonconvulsive status epilepticus is an electroclinical state associated with an altered level of consciousness but lacking convulsive motor activity and has been reported in fat embolism. The diagnosis is clinical and is treated with supportive care, antiepileptic therapy, and sedation. A 56-year-old male presented with altered mental status following internal fixation for an acute right femur fracture due to a motor vehicle accident 24 hours earlier. Continued neuromonitoring revealed nonconvulsive status epilepticus. Magnetic resonance imaging of the brain showed multiple bilateral acute cerebral infarcts with a specific pattern favoring the diagnosis of fat embolism syndrome. He was found to have a significant right to left intracardiac shunt on a transesophageal echocardiogram. He improved substantially over time with supportive therapy, was successfully extubated on day 6, and discharged to inpatient rehabilitation on postoperative day 15. Fat embolisms can result in a wide range of neurologic manifestations. Nonrefractory nonconvulsive status epilepticus that responds to antiepileptic drugs, sedation, and supportive therapy can have a favorable outcome. A high index of suspicion and early recognition reduces the chances of unnecessary interventions and may improve survival.

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.

The Protective Roles of Urinary Trypsin Inhibitor in Brain Injury Following Fat Embolism Syndrome in a Rat Model

Fat embolism syndrome (FES) is a common complication following long bone fracture; fat droplets are released into the blood circulation and form embolisms, mainly in lung and brain. However, the potential mechanisms involved remain to be clarified. In this study, the mechanism of brain injury following FES and the protective effects of urinary trypsin inhibitor (UTI)—a serine protease inhibitor—were investigated. Sixty male Sprague-Dawley rats were divided randomly into sham, FES and FES+UTI treatment groups. The FES model was established using tail vein injection of glycerol trioleate, and UTI was administered by intraperitoneal injection immediately following FES. Brain/lung water content evaluation, Evans blue content and magnetic resonance imaging examination were used to assess the effects of UTI. Furthermore, immunohistochemistry and western blot were also applied to explore the protective mechanism of UTI following FES. The results of oil red O staining indicated that the FES model was successfully established. UTI could significantly attenuate blood-brain-barrier (BBB) disruption, as seen through brain edema evaluation and Evans blue content examination. Immunofluorescence staining results indicated that the TLR4-JNK pathway was involved in brain injury after FES; this effect could be quenched by UTI treatment. Furthermore, UTI could decrease the levels of downstream target proteins of the TLR4-JNK pathway, phosphorylated-NF- κB (p65) and p53 in brain. Our results showed that UTI could alleviate BBB injury after FES through blocking activity of the TLR4-JNK pathway.

Cerebral fat embolism syndrome (FES): similar cases with different outcomes

Fat embolism syndrome (FES) is a rare multisystem, clinical syndrome occurring in 0.9%-2.2% of long-bone fractures. The severity of FES can vary from subclinical with mild respiratory changes and haematological aberrations to a fulminant state characterised by sudden onset of severe respiratory and neurological impairment. Here we present two patients with cerebral FES secondary to femur fracture. Both patients exhibited profound neurological impairment with varied outcomes. Our cases highlight the importance of a high clinical suspicion of FES in patients with long-bone fractures and neurological deterioration. We recommend early plate osteosynthesis to prevent additional emboli in patients with FES and situational placement of intracranial pressure monitoring. Finally, cerebral FES has low mortality even in a patient with tentorial herniation and fixed, dilated pupils.

Critical Differences between Microscopic (MIFE) and Macroscopic (MAFE) Fat Embolism during Liposuction and Gluteal Lipoinjection

BACKGROUND

Liposuction and gluteal lipoinjection are two of the most frequent surgical procedures in body contouring surgery, and two of the most important complications are microscopic (MIFE) and macroscopic (MAFE) fat embolism. Despite a high index of morbidity and mortality, few reports exist about these complications, and although they have the same causal agent, their etiopathogenesis, clinical evolution, treatment, prognosis, and prevention are totally different. Therefore, the authors performed a comprehensive review of the literature to exhaustively analyze both pathologic conditions and present the differences between them.

METHODS

A detailed search was carried out in PubMed of studies on humans from 1946 to March of 2017 in any language and including the keywords microscopic fat embolism and macroscopic fat embolism with either liposuction or gluteal lipoinjection. The articles found were selected according to the search criteria and were analyzed to provide the final data and recommendations.

RESULTS

Of the 1245 and 26 articles that were found on complications related to liposuction and gluteal lipoinjection, respectively, only 41 on liposuction and microscopic fat embolism and seven on gluteal lipoinjection and microscopic fat embolism met the specific criteria for inclusion in the analysis. Only two articles on liposuction and two on gluteal lipoinjection referred to macroscopic fat embolism as a complication.

CONCLUSION

Although microscopic fat embolism and macroscopic fat embolism are pathologic conditions with high morbidity and mortality rates in association with liposuction and gluteal lipoinjection, few reports about them exist; therefore, the authors made recommendations based on this study for their diagnosis, prevention, and treatment.

Pulmonary Fat Embolism and Coronary Amyloidosis

Patient: Male, 72

Final Diagnosis: Fat lung embolism

Symptoms: Dyspnea

Medication: —

Clinical Procedure: —

Specialty: Orthpedics and Traumatology

A Systematic Review of the Causes and Management of Nonthrombotic Embolic Stroke of Tissue Origin

Introduction

Various bodily tissues have been reported to enter the arterial circulation and embolize to the brain resulting in ischemic stroke. Most frequently nonthrombotic embolic stroke (NTES) of tissue origin is iatrogenic or related to an underlying disease process. With the increase in elective surgery and intravascular procedures, NTES may increase in prevalence.

Aim

To compile a summary of the background, incidence, presentation, and treatment of NTES of tissue origin, by conducting a systematic review of the current literature.

Summary of Review

We searched EMBASE and MEDLINE for articles on NTES of tissue origin published in English with no restriction on publication date (search date June 2017). 800 articles were identified and screened and 159 articles were ultimately reviewed in full text and included in qualitative analysis. Articles deemed relevant were assessed by a second reviewer to confirm compatibility with the inclusion criteria. References of included articles were reviewed for relevant publications. We categorized the pathology of the emboli into the following groups: amniotic fluid (4 publications), tumour (60 publications), fat (43 publications), cholesterol (19 publications), and intravascular debris (12 publications). We then summarized the available literature on each cause of NTES.

Conclusions

NTES of tissue origin is an uncommon but important diagnosis to consider particularly in younger stroke patients and in certain clinical settings. Treatment for NTES is currently anecdotal and based on small case series. Embolectomy may emerge as the therapy of choice due to the longer treatment timeframe and heterogeneity of the emboli.

A case of fat embolism syndrome complicated by diffuse alveolar hemorrhage

Fat embolism syndrome is a life-threatening condition that may develop after orthopedic trauma and surgery. Fat embolism is caused by lipid droplets in the systemic circulation inducing mechanical or biochemical injury. Diagnosis is clinical and treatment is supportive. Clinical features including respiratory changes, neurological abnormalities, and petechial rashes generally present 12–72 h after the initial injury. However, respiratory failure accompanying diffuse alveolar hemorrhage in fat embolism syndrome is rare. This report describes a 44-year-old male patient suffering from fat embolism syndrome with diffuse alveolar hemorrhage caused by traumatic long bone fracture, in which mechanical ventilation was required to provide respiratory support.

Purtscher-like retinopathy - A rare complication of acute myocardial infarction and a review of the literature

Purtscher-like retinopathy is an uncommon condition with features similar to Purtscher retinopathy but have non-traumatic causes. Several pathogenic mechanisms have been put forth with differing views on treatment options. We describe for the first time, a case of Purtscher-like retinopathy which developed following a myocardial infarct and a transient ischemic attack. We present a review of the literature on this condition, describing the various clinical presentations, investigation findings, treatment options and prognosis.

Bone marrow necrosis and fat embolism syndrome: a dreadful complication of hemoglobin sickle cell disease

Sickle cell disease encompasses a wide range of genotypic presentation with particular clinical features. The entity affects millions of people, particularly those whose ancestors came from sub-Saharan Africa and other countries in the Western Hemisphere, Saudi Arabia, and India. Currently, the high frequency of S and C genes reflects natural selection through the protection of heterozygotes against severe malaria, the high frequency of consanguineous marriages, improvement of some public health policies and the nutritional standards in the poorer countries where newborns are now living long enough to present for diagnosis and management. Although there is a high burden of the disease, in many countries, the new-born sickle cell screening test is being performed and is rendering an early diagnosis; however, it is still difficult for sickle cell patients to find proper treatment and adequate follow-up. Moreover, in many countries, patients are neither aware of their diagnosis nor the care they should receive to prevent complications; also, they do not receive adequate genetic counseling. Hemoglobin SC (HbSC) disease is the most frequent double sickle cell heterozygosis found in Brazil. The clinical course tends to be more benign with fewer hospitalizations compared with double homozygotic SS patients. However, HbSC patients may present severe complications with a fatal outcome. We report the case of a 36-year-old man who presented to the emergency care facility with symptoms consistent with the diagnosis of sickling crisis. The outcome was unfavorable and death occurred just hours after admission. The autopsy revealed a generalized vaso-occlusive crisis by sickled red cells, bone marrow necrosis, and fat embolism syndrome.

Fat embolism after fractures in Duchenne muscular dystrophy: an underdiagnosed complication? A systematic review

Duchenne muscular dystrophy is the most frequent lethal genetic disease. Several clinical trials have established both the beneficial effect of steroids in Duchenne muscular dystrophy and the well-known risk of side effects associated with their daily use. For many years it has been known that steroids associated with ambulation loss lead to obesity and also damage the bone structure resulting in the bone density reduction and increased incidence of bone fractures and fat embolism syndrome, an underdiagnosed complication after fractures. Fat embolism syndrome is characterized by consciousness disturbance, respiratory failure and skin rashes. The use of steroids in Duchenne muscular dystrophy may result in vertebral fractures, even without previous trauma. Approximately 25% of patients with Duchenne muscular dystrophy have a long bone fracture, and 1% to 22% of fractures have a chance to develop fat embolism syndrome. As the patients with Duchenne muscular dystrophy have progressive cardiac and respiratory muscle dysfunction, the fat embolism may be unnoticed clinically and may result in increased risk of death and major complications. Different treatments and prevention measures of fat embolism have been proposed; however, so far, there is no efficient therapy. The prevention, early diagnosis and adequate symptomatic treatment are of paramount importance. The fat embolism syndrome should always be considered in patients with Duchenne muscular dystrophy presenting with fractures, or an unexplained and sudden worsening of respiratory and cardiac symptoms.

Strategies for Reducing Fatal Complications in Liposuction

BACKGROUND

Liposuction has become one of the most common cosmetic surgical procedures, and severe complications secondary to this procedure have also increased significantly. That is why we carry out a research work to know the most frequent severe complications reported in the scientific literature to indicate criteria for prevention.

METHODS

English-language scientific publications about liposuction and its complications were analyzed using the PubMed.gov, from the beginning of PubMed's history through June 10, 2017. Five terms were used to define liposuction and its complications: "liposuction," "liposuction AND complications," liposuction AND major complications," "liposuction AND complications AND death," and "liposuction AND death." The quantities of results for the 5 phrases were analyzed, along with their contents.

RESULTS

One thousand sixty-three results were obtained from 1973 through June 10, 2017 for the phrase "Liposuction and Complications" in humans; for "Liposuction and Major Complications," 153 articles were found; for "Liposuction and Deaths," 89 articles were found; and 42 articles were obtained with the terms "Liposuction and Major Complications and Deaths." After final depuration, all those that were not specific to severe liposuction complications were eliminated, leaving a total of 39 articles that were included in our study. Five problems proved to be the most serious complications when performing liposuction: Thromboembolic disease, fat embolism, pulmonary edema, lidocaine intoxication, and intraabdominal visceral lesion.

CONCLUSIONS

The 5 most important complications that can cause death in liposuction are easily preventable using simple measures and proper safety protocols that are described in this work.

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.

The renin inhibitor aliskiren protects rat lungs from the histopathologic effects of fat embolism

BACKGROUND

Fat embolism (FE) and the consequent FE syndrome occurring after trauma or surgery can lead to serious pulmonary injury, including ARDS and death. Current treatment of FE syndrome is limited to supportive therapy. We have shown in a rat model that the renin angiotensin system plays a significant role in the pathophysiology of FE because drugs interfering with the renin angiotensin system, captopril and losartan reduce the histopathologic pulmonary damage. The purpose of the current study was to determine if inhibition of renin by aliskiren, an FDA-approved drug for treating hypertension, would produce effective protection in the same model.

METHODS

The FE model used intravenous injection of the neutral fat triolein in unanesthetized rats. Intraperitoneal injections of saline or aliskiren at either 50 or 100 mg/kg were performed 1 hour after FE induction via triolein. Rats were euthanized at 48 hours, and various histologic stains were used to examine the lungs.

RESULTS

(1) Fibrosis: rats treated with triolein showed significant fibrotic changes with increased collagen and myofibroblast activation (p < 0.0001 for both trichrome and α-smooth muscle actin staining). Aliskiren blocked this inflammatory and profibrotic process to a level indistinguishable from the controls (p < 0.0001 for both trichrome and α-smooth muscle actin staining). (2) Fat: rats treated with triolein showed a statistically significant increase in fat (p = 0.0006). Subsequent aliskiren administration at both doses reduced the size, distribution, and amount of fat droplets (low dose, p = 0.0095; high dose, p = 0.0028). (3) Vessel patency: the low dose of aliskiren blocked the reduction of lumen patency observed after triolein administration (p = 0.0058).

CONCLUSIONS

Aliskiren protected the lungs of rats from gross and histopathologic FE-induced pulmonary damage at 48 hours. Clinical implications include the use of aliskiren both prophylactically (before certain orthopedic procedures) and therapeutically (after severe trauma) to prevent the consequent severe pulmonary pathologic sequelae.

Integrating Fat Embolism Syndrome Scoring Indices in Sickle Cell Disease: A Practice Management Review

Fat embolism syndrome (FES) has been described in the literature as a rare complication of sickle cell disease (SCD). A review article published in 2005 reported 24 cases of FES associated with SCD. In many cases, a definitive diagnosis of FES in SCD is made on autopsy because of the lack of early recognition and the paucity of sensitive and specific testing for this syndrome. Patients with FES usually have a fulminant, rapidly deteriorating clinical course with mortality occurring within the first 24 hours. We postulate that FES is not well recognized in SCD and that FES scores are useful diagnostic tools in patients with SCD. We queried the electronic medical records with the diagnostic codes for SCD with acute chest syndrome (ACS), pulmonary embolism, or acute respiratory distress syndrome admitted to our hospital from 2008 to 2016 to identify patients suspected of having FES. In addition, we performed an extensive literature review to evaluate the management practice of pediatric patients with FES and SCD from 1966 to 2016. Six patients met our selection criteria from the hospital records, and 4 case reports from the literature search were also included. We applied the Gurd and Wilson criteria and the Schonfeld Fat Embolism Index to identify patients who met the criteria for FES. Nine patients fulfilled Gurd and Wilson criteria, and 9 patients who were evaluable met the Schonfeld criteria for FES. A rapidly deteriorating clinical course in a patient with SCD presenting with ACS or severe vaso-occlusive crisis should trigger a high index of suspicion for FES. Gurd and Wilson criteria or the Schonfeld Fat Embolism Index are useful diagnostic tools for FES in SCD.

An autopsy case of non-traumatic fat embolism syndrome

Fat embolism syndrome (FES) occurs after long bone fractures and the symptoms appear 24-72 h after the initial trauma. Fat emboli can affect both the pulmonary and systemic circulation. Apart from the most common type of FES that originates from bone fracture, non-traumatic FES has been also reported. We have experienced an autopsy case of non-traumatic FES. An 81-year-old man with hepatocellular carcinoma associated with alcoholic liver cirrhosis suddenly lost consciousness before transcatheter arterial chemoembolization treatment for his disease and died 5 h after the episode. At autopsy, numerous fat droplets were detected in the alveolar capillaries of the lung and glomerular capillaries of the kidney. Lipid analysis of lung autopsy specimens by thin-layer chromatography showed that the emboli were composed mainly of tristearin. Free fatty acids (FFA) has been considered to be the main component of fat emboli and can be a cause of acute respiratory distress syndrome (ARDS). However, in the present case, the lung specimen contained tristearin and ARDS did not occur. This is the first report of non-traumatic FES in which lipid analysis of human autopsy specimens has been conducted.

Fat emboli syndrome and the orthopaedic trauma surgeon: lessons learned and clinical recommendations

PURPOSE

Fat emboli syndrome is a rare but well-described complication of long-bone fractures classically characterised by a triad of respiratory failure, mental status changes and petechial rash. In this paper, we present the case of a patient who sustained bilateral femoral fractures and subsequently developed FES. Our aim was to review and summarise the current literature regarding the pathophysiology and management of fat emboli syndrome (FES) and propose an algorithm for treating patients with bilateral femoral fractures to reduce the risk of FES.

METHODS

A literature analysis was performed to determine implications in the clinical setting.

RESULTS

Currently, there exists little high-quality evidence to guide the orthopaedic surgeon in identifying patients at highest risk of FES or in preventing FES in patients with multiple long-bone fractures. However, the literature does suggest that the risk is directly related to the volume of marrow displaced and inversely related to both the time to fracture stabilisation and the respiratory reserve of the patient. Based on these correlations, we propose an algorithm for treating patients with bilateral femoral fractures, taking into consideration haemodynamic and pulmonary stability.

CONCLUSIONS

Our algorithm for managing bilateral femoral fractures prioritises early stabilisation with external fixation, staged intramedullary nailing and conversion to plate fixation if FES develops. This protocol is meant to be the basis of future investigations of optimal treatment strategies.

Fat embolism syndrome: What have we learned over the years?

Although its original clinical description dates from the nineteenth century, fat embolism syndrome remains a diagnostic challenge for clinicians. Fat emboli occur in all patients with long-bone fractures, but only few of them develop a multisystem disorder affecting the lung, brain, and skin, also known as fat embolism syndrome (FES). The incidence of FES varies and is often underestimated. Mechanical and biochemical theories have been proposed for the pathophysiology of FES. Clinical manifestations consist of respiratory and cerebral dysfunction and a petechial rash. Diagnosis of FES is difficult and based mainly on clinical criteria. FES is a self-limiting disease and treatment needs to be mainly supportive. Surgical treatment of the coexistent injuries is still obscured by controversies and the treatment methods used provide inconclusive results. In this context, prevention focuses on the early identification of predisposing factors.

Prospective Randomized Clinical Trial Investigating the Effect of the Reamer-Irrigator-Aspirator on the Volume of Embolic Load and Respiratory Function During Intramedullary Nailing of Femoral Shaft Fractures

OBJECTIVES

We sought to determine whether the use of the Reamer-Irrigator-Aspirator (RIA) device resulted in a decreased amount of fat emboli compared with standard reaming (SR) when performing intramedullary (IM) nailing of femoral shaft fractures.

DESIGN

Prospective randomized clinical trial.

SETTING

Multi-centered trial, level I trauma centers.

PATIENTS/PARTICIPANTS

All eligible patients who presented to participating institutions with an isolated femoral shaft fracture amenable to fixation with antegrade IM nailing. Thirty-one patients were enrolled: nine were excluded because of technical difficulties with the transesophageal echocardiogram (TEE) recording. Therefore, the study comprised 22 patients: 11 patients randomized to the SR group and eleven patients randomized to the RIA group.

INTERVENTION

Antegrade IM nailing of a femoral shaft fracture with standard reamers or the RIA device. All patients were monitored intraoperatively with a continuous TEE to assess embolic events in the right atrium. A radial arterial line was used to monitor blood gases and potential systemic effects of emboli.

MAIN OUTCOME MEASURE

Duration, size, and severity of emboli as measured by TEE. The operative procedure was divided into 6 distinct stages: preoperative, reduction, guidewire passage, reaming, nail insertion, and postoperative.

RESULTS

There was no significant difference in emboli between the RIA and SR groups preoperatively, during fracture reduction, guidewire insertion, or postoperatively. Measured with a standardized scoring system, there was a modest reduction in total emboli score in the RIA group during reaming (SR 5.30 [SD; 1.81] vs. RIA 4.05 [SD; 2.19], P = 0.005) and during nail insertion (SR 5.09 [SD; 1.74] vs. RIA 4.25 [SD; 1.89], P = 0.03). We were unable to correlate this reduction with any improvement in physiologic parameters (mean arterial pressure, end-tidal CO2, O2 saturation, pH, paO2, and paCO2).

CONCLUSIONS

This study showed a modest reduction of embolic debris during the reaming and nail insertion segments of the operative procedure. We were unable to correlate this with any change in physiologic parameters.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Fat Embolism Syndrome: Lung Computed Tomography Findings in 18 Patients

OBJECTIVE

The purpose of this study was to evaluate the lung computed tomography (CT) findings in fat embolism (FE) syndrome.

METHODS

We retrospectively evaluated 19 CT examinations of 18 patients with FE syndrome, diagnosed clinically using the Gurd and Wilson criteria.

RESULT

Fat embolism syndrome showed 3 patterns: negative examination, bilateral interstitial-alveolar involvement, and adult respiratory distress syndrome like. Frequent findings included consolidations (17 patients), mostly with gravity dependent distribution, and ground-glass opacities (17 patients), mostly with patchy distribution. Fifteen patients showed an overlapping random nodular pattern. Less common findings included lobular ground-glass opacities and lobular consolidations, smooth septal thickening, thickening of the bronchial wall, and areas of crazy paving. The extension of the consolidations correlates with the duration of assisted ventilation.

CONCLUSIONS

In FE syndrome, pulmonary CT findings are ground-glass opacities and dependent consolidations, associated with other variably overlapping signs, such as lobular opacities, random nodules, septal thickening, and bronchial wall thickening.

Pathogenesis, diagnosis and treatment of cerebral fat embolism

In this study, we analyzed two cases of pure cerebral fat embolism and reviewed related literatures to explore the pathogenesis, clinical manifestations, diagnosis and treatment of cerebral fat embolism, improve the treatment efficiency and reduce the misdiagnosis rate. In our cases, patients fully returned to consciousness at the different times with good prognosis, normal vital signs and without obvious sequelae. For patients with the limb fractures, who developed coma without chest distress, dyspnea or other pulmonary symptoms 12 or 24 h post injury, cerebral fat embolism should be highly suspected, except for those with intracranial lesions, such as delayed traumatic intracerebral hemorrhage, etc. The early diagnosis and comprehensive treatment can improve prognosis.

Ultrasound in cardiac trauma

In the perioperative period, the emergency department or the intensive care unit accurate assessment of variable chest pain requires meticulous knowledge, diagnostic skills, and suitable usage of various diagnostic modalities. In addition, in polytrauma patients, cardiac injury including aortic dissection, pulmonary embolism, acute myocardial infarction, and pericardial effusion should be immediately revealed and treated. In these patients, arrhythmias, mainly tachycardia, cardiac murmurs, or hypotension must alert physicians to suspect cardiovascular trauma, which would potentially be life threatening. Ultrasound of the heart using transthoracic and transesophageal echocardiography are valuable diagnostic tools that can be used interchangeably in conjunction with other modalities such as the electrocardiogram and computed tomography for the diagnosis of cardiovascular abnormalities in trauma patients. Although ultrasound of the heart is often underused in the setting of trauma, it does have the advantages of being easily accessible, noninvasive, and rapid bedside assessment tool. This review article aims to analyze the potential cardiac injuries in trauma patients, and to provide an elaborate description of the role of echocardiography for their accurate diagnosis.

Staged Correction of Severe Thoracic Kyphosis in Patients with Multilevel Osteoporotic Vertebral Compression Fractures

Study Design Technical report. Objective Multilevel osteoporotic vertebral compression fractures may lead to considerable thoracic deformity and sagittal imbalance, which may necessitate surgical intervention. Correction of advanced thoracic kyphosis in patients with severe osteoporosis remains challenging, with a high rate of failure. This study describes a surgical technique of staged vertebral augmentation with osteotomies for the treatment of advanced thoracic kyphosis in patients with osteoporotic multilevel vertebral compression fractures. Methods Five patients (average age 62 ± 6 years) with multilevel osteoporotic vertebral compression fractures and severe symptomatic thoracic kyphosis underwent staged vertebral augmentation and surgical correction of their sagittal deformity. Clinical and radiographic outcomes were assessed retrospectively at a mean postoperative follow-up of 34 months. Results Patients' self-reported back pain decreased from 7.2 ± 0.8 to 3.0 ± 0.7 (0 to 10 numerical scale; p < 0.001). Patients' back-related disability decreased from 60 ± 10% to 29 ± 10% (0 to 100% Oswestry Disability Index; p < 0.001). Thoracic kyphosis was corrected from 89 ± 5 degrees to 40 ± 4 degrees (p < 0.001), and the sagittal vertical axis was corrected from 112 ± 83 mm to 38 ± 23 mm (p = 0.058). One patient had cement leakage without subsequent neurologic deficit. Decreased blood pressure was observed in another patient during the cement injection. No correction loss, hardware failure, or neurologic deficiency was seen in the other patients. Conclusion The surgical technique described here, despite its complexity, may offer a safe and effective method for the treatment of advanced thoracic kyphosis in patients with osteoporotic multilevel vertebral compression fractures.

Spinal cord infarction as a rare complication of fat embolism syndrome following bilateral intramedullary nailing of femur fractures

Fat embolism syndrome (FES) is a rare and potentially fatal complication occurring most often after long bone or pelvic fractures and orthopaedic procedures. It can consist of pulmonary, central nervous system and cutaneous manifestations. The exact pathophysiology of emboli reaching the arterial circulation is poorly understood.1 It is suggested that this may occur by either 'paradoxical' embolism or microembolism.2 3 Its true incidence is unknown but increases in the presence of multiple closed fractures. It can be a diagnostic dilemma for clinicians and if suspected diffusion-weighted MRI is the modality of choice for the investigation of the central nervous system.4 We present the case of a 22-year-old man who developed multifocal cerebral infarcts, a right-sided cerebellar infarct and an infarct in the anterior cord bilaterally at the level of C5-C6 as a result of FES.