Fat embolism: the hidden murder for trauma patients!

INTRODUCTION: fat embolism syndrome (FES) is an acute respiratory disorder that occurs when an inflammatory response causes the embolization of fat and marrow particles into the bloodstream. The exact incidence of FES is not well defined due to the difficulty of diagnosis. FES is mostly associated with isolated long bone trauma, and it is usually misdiagnosed in other trauma cases. The scope of this study was to identify and search the current literature for cases of FES in nonorthopedic trauma patients with the aim of defining the etiology, incidence, and main clinical manifestations. METHODS: we perform a literature search via the PubMed journal to find, summarize, and incorporate reports of fat embolisms in patients presenting with non-orthopedic trauma. RESULTS: the final literature search yielded 23 papers of patients presenting with fat embolism/FES due to non-orthopedic trauma. The presentation and etiology of these fat embolisms is varied and complex, differing from patient to patient. In this review, we highlight the importance of maintaining a clinical suspicion of FES within the trauma and critical care community. CONCLUSION: to help trauma surgeons and clinicians identify FES cases in trauma patients who do not present with long bone fracture, we also present the main clinical signs of FES as well as the possible treatment and prevention options.

Severe Hemodynamic Collapse During Humerus Stabilization with Photodynamic Implant: A Report of Two Cases.

CASE: We present 2 cases of severe hemodynamic collapse during prophylactic stabilization of impending pathologic humerus fractures using a photodynamic bone stabilization device. Both events occurred when the monomer was infused under pressure into a balloon catheter. CONCLUSION: We suspect that an increase in intramedullary pressure during balloon expansion may cause adverse systemic effects similar to fat embolism or bone cement implantation syndrome. Appropriate communication with the anesthesia team, invasive hemodynamic monitoring, and prophylactic vent hole creation may help mitigate or manage these adverse systemic effects.

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

OBJECTIVE: To explore characteristics of clinical and imaging findings in patients with fat embolism syndrome. METHODS: From January 2021 to October 2022,clinical manifestations of 13 patients with fat embolism due to fracture or orthopaedic surgery were retrospectively analyzed,including 11 males and 2 females,aged from 17 to 60 years old. Mental and respiratory abnormalities and changes in vital signs occurred after admission or after surgery,and patient's chest and brain imaging results were abnormal. The patient's mental and respiratory abnormalities,vital signs,chest and brain imaging results were continuously monitored. RESULTS: The main clinical manifestations of fat embolism syndrome were abnormal pulmonary respiration in 13 patients,abnormal central nervous function in 7 patients,and spotted rash in 2 patients. Chest CT showed diffuse distribution of ground glass shadows in 13 patients,and severe symptoms were "snowstorm". Nine patients with ground glass fusion consolidation,5 patients with multiple nodules and 4 patients accompanied by bilateral pleural effusion. Head CT findings of 5 patients were negative,and head MRI findings of 1 patient showed multiple T1WI low signal,T2WI high signal shadow,DWI high signal shadow,and "starry sky sign" in basal ganglia,radiative crown,hemioval center,thalamus,frontal parietal cortex and subcortex. CONCLUSION: Fat embolism syndrome has a high mortality rate. Clinical manifestations of respiratory system and nervous system are not specific,and the skin spot rash has a characteristic manifestation. The "blizzard" sign is the specific manifestation of chest X-ray and CT examination of fat embolism,and the "starry sky" sign is the typical manifestation of diffusion-weighted sequence of brain MRI examination of fat embolism.

Pulmonary fat embolism in non-survivors after cardiopulmonary resuscitation.

BACKGROUND: Blunt trauma acting against the human body presents the fundamental cause of pulmonary fat embolism (PFE) and fat embolism syndrome. The aim of the present study was to investigate PFE in non-survivors after cardiopulmonary resuscitation (CPR). METHODS: This was a prospective cohort study conducted in University Hospital Ostrava, Czech Republic. Within a 4-year study period, all non-survivors after CPR because of out-of-hospital cardiac arrest were assessed for the study eligibility. The presence/seriousness of PFE was determined by microscopic examination of cryo-sections of lung tissue (staining with Oil Red O). RESULTS: In total, 106 persons after unsuccessful CPR were enrolled in the study. The most frequent cause of death in the study population (63.2% of cases) was cardiac disease (ischemic heart disease); PFE was not determined as the cause of death in any of our study cases. Sternal fractures were identified 66.9%, rib fractures (usually multiple) in 80.2% of study cases; the median number of rib fractures was 10.2 fractures per person. Serious intra-thoracic injuries were found in 34.9% of cases. Microscopic examination of lung cryo-sections revealed PFE in 40 (37.7%) study cases; PFE was most frequently evaluated as grade I or II. Occurrence of sternal and rib fractures was significantly higher in persons with PFE than between persons without PFE (p = 0.033 and p = <0.001). Number of rib fractures was also significantly higher in persons with PFE. The occurrence of serious intra-thoracic injuries was comparable in both our study groups (p = 0.089). CONCLUSIONS: PFE presents a common resuscitation injury which can be found in more than 30% of persons after CPR. Persons with resuscitation skeletal chest fractures have significantly higher risk of PFE development. During autopsy of persons after unsuccessful CPR, it is necessary to distinguish CPR-associated injuries including PFE from injuries that arise from other mechanisms.

Fat embolism syndrome associated with atraumatic compartment syndrome of the bilateral upper extremities: An unreported etiology.

Fat embolism syndrome (FES) is a potentially life-threatening condition that develops when fat embolism leads to clinical symptoms and multisystem dysfunction. The classic triad of respiratory distress, neurologic symptoms, and petechial rash are non-specific, and the lack of specific laboratory tests makes the diagnosis of FES difficult. Although FES is most common after long bone fractures, multiple conditions some of which are atraumatic have been associated with the development of FES. We report a case of FES that occurred in the setting of a non-traumatic compartment syndrome of the upper extremities. The pathologic and clinical findings, pathophysiology, diagnostic challenges, and pathologic methods to properly diagnose FES are discussed with a review of the relevant literature. This case highlights the importance of the autopsy in making a diagnosis of FES in cases where death could otherwise be incorrectly attributed to multi-organ system failure, shock, or sepsis.

In vivo study to assess fat embolism resulting from the Reamer-Irrigator-Aspirator 2 system compared to a novel aspirator-based concept for intramedullary bone graft harvesting.

INTRODUCTION: Fat embolism (FE) following intramedullary (IM) reaming can cause severe pulmonary complications and sudden death. Recently, a new harvesting concept was introduced in which a novel aspirator is used first for bone marrow (BM) aspiration and then for subsequent aspiration of morselized endosteal bone during sequential reaming (A + R + A). In contrast to the established Reamer-Irrigator-Aspirator (RIA) 2 system, the new A + R + A concept allows for the evacuation of fatty BM prior to reaming. In this study, we hypothesized that the risk of FE, associated coagulopathic reactions and pulmonary FE would be comparable between the RIA 2 system and the A + R + A concept. MATERIALS AND METHODS: Intramedullary bone graft was harvested from intact femora of 16 Merino sheep (age: 1-2 years) with either the RIA 2 system (n = 8) or the A + R + A concept (n = 8). Fat intravasation was monitored with the Gurd test, coagulopathic response with D-dimer blood level concentration and pulmonary FE with histological evaluation of the lungs. RESULTS: The total number and average size of intravasated fat particles was similar between groups (p = 0.13 and p = 0.98, respectively). D-dimer concentration did not significantly increase within 4 h after completion of surgery (RIA 2: p = 0.82; A + R + A: p = 0.23), with an interaction effect similar between groups (p = 0.65). The average lung area covered with fat globules was similar between groups (p = 0.17). CONCLUSIONS: The use of the RIA 2 system and the novel A + R + A harvesting concept which consists of BM evacuation followed by sequential IM reaming and aspiration of endosteal bone, resulted in only minor fat intravasation, coagulopathic reactions and pulmonary FE, with no significant differences between the groups. Our results, therefore, suggest that both the RIA 2 system and the new A + R + A concept are comparable technologies in terms of FE-related complications.

Cerebral fat emboli in a patient with paraplegia caused by bilateral femur fractures.

Cerebral fat embolism is a rare cause of stroke and therefore an overlooked diagnosis. Often it is seen as a consequence of major bone fractures or after arthroplasty, and can lead to respiratory or circulatory collapse. We present a case of a patient with a history of paraplegia after a thoracic spinal cord injury that developed cerebral fat embolism following a bilateral femur fracture. Since the patient was paraplegic and with an altered mental state upon admission, femoral bone fractures were not initially suspected. The case shows the difficulties in diagnosing this condition.

Fat embolism syndrome in Duchenne muscular dystrophy: Report on a novel case and systematic literature review.

We report a non-ambulatory 13-year-old boy with Duchenne muscular dystrophy who experienced severe acute respiratory distress syndrome and cerebral fat embolism following elective soft tissue surgery. Post-surgery radiological examination revealed bilateral femoral fractures and marked osteopenia that were believed to have caused disseminated pulmonary and cerebral fat embolism. The patient had never been on glucocorticoid treatment. Five months post-surgery, he remained in a state of minimal consciousness. A literature review was performed and eleven publications included, providing case reports of a total number of 23 patients with Duchenne muscular dystrophy with fat embolism syndrome. The most common causes were falls from the wheelchair that predominantly resulted in femoral fractures. Median age at the event was around 14 years. Seven patients succumbed to complications of fat embolism. No event was described in the context of surgery. We want to raise awareness that spontaneous unnoticed fractures may occur especially in adolescents with DMD from traumatic injury of large bones and also during elective surgery with a high risk of causing fat embolism with severe sequelae.

A diagnostic strategy for pulmonary fat embolism based on routine H&E staining using computational pathology.

Pulmonary fat embolism (PFE) as a cause of death often occurs in trauma cases such as fractures and soft tissue contusions. Traditional PFE diagnosis relies on subjective methods and special stains like oil red O. This study utilizes computational pathology, combining digital pathology and deep learning algorithms, to precisely quantify fat emboli in whole slide images using conventional hematoxylin-eosin (H&E) staining. The results demonstrate deep learning's ability to identify fat droplet morphology in lung microvessels, achieving an area under the receiver operating characteristic (ROC) curve (AUC) of 0.98. The AI-quantified fat globules generally matched the Falzi scoring system with oil red O staining. The relative quantity of fat emboli against lung area was calculated by the algorithm, determining a diagnostic threshold of 8.275% for fatal PFE. A diagnostic strategy based on this threshold achieved a high AUC of 0.984, similar to manual identification with special stains but surpassing H&E staining. This demonstrates computational pathology's potential as an affordable, rapid, and precise method for fatal PFE diagnosis in forensic practice.

Augmented Safety Profile of Ultrasound-Guided Gluteal Fat Transfer: Retrospective Study With 1815 Patients.

BACKGROUND: Gluteal augmentation with autologous fat transfer is one of the fastest growing aesthetic surgical procedures worldwide over the past decade. However, this procedure can be associated with high mortality from fatal pulmonary fat embolism events caused by intramuscular injection of fat. Ultrasound-guided fat grafting allows visualization of the transfer in the subcutaneous space, avoiding intramuscular injection. OBJECTIVES: The aim of this study was to assess the safety and efficacy of gluteal fat grafting performed with ultrasound-guided cannulation. METHODS: A retrospective chart review of all patients undergoing ultrasound-guided gluteal fat grafting at the authors' center between 2019 and 2022 was performed. All cases were performed by board-certified and board-eligible plastic surgeons under general anesthesia in ASA Class I or II patients. Fat was only transferred to the subcutaneous plane when over the gluteal muscle. Patients underwent postoperative follow-up from a minimum of 3 months up to 2 years. Results were analyzed with standard statistical tests. RESULTS: The study encompassed 1815 female patients with a median age of 34 years. Controlled medical comorbidities were present in 14%, with the most frequent being hypothyroidism (0.7%), polycystic ovarian syndrome (0.7%), anxiety (0.6%), and asthma (0.6%). Postoperative complications occurred in 4% of the total cohort, with the most common being seroma (1.2%), local skin ischemia (1.2%), and surgical site infection (0.8%). There were no macroscopic fat emboli complications or mortalities. CONCLUSIONS: These data suggest that direct visualization of anatomic plane injection through ultrasound guidance is associated with a low rate of complications. Ultrasound guidance is an efficacious adjunct to gluteal fat grafting and is associated with an improved safety profile that should be considered by every surgeon performing this procedure.

Pulmonary fat embolism after cardiopulmonary resuscitation.

Pulmonary fat embolism (PFE) is usually observed in patients with long bone fractures, patients with extensive subcutaneous fat contusions or skin burns. Chest compressions during cardiopulmonary resuscitation (CPR) present powerful repetitive violence against victim's chest. Skeletal chest fractures are the most frequent complication of CPR, and probably the most important cause of PFE autopsy finding in persons, which have been resuscitated before death. The aim of the present paper was to investigate the prevalence and seriousness of PFE in non-survivors after out-of-hospital cardiac arrest. During autopsy, PFE can be diagnosed in 30 - 42 % of persons after unsuccessful CPR; skeletal chest fractures are associated with significantly higher prevalence of PFE. After successful CPR, fat embolism may contribute significantly to acute respiratory distress syndrome, or multiorgan failure. The issue of CPR associated injuries has two medical aspects - clinical and forensic. From clinical point of view, the presence of CPR associated injuries must be acknowledged when offering healthcare to patients after successful CPR. During autopsy, CPR associated injuries should be diagnosed and evaluated as these injuries may contribute to death or may be potentially lethal.

Low pressure headache and cerebral fat embolism from a sacral fracture through a Tarlov cyst: a case report.

BACKGROUND: Here we report the only formally documented case in the United Kingdom, to our knowledge, of a cerebral fat embolism secondary to non-iatrogenic trauma through a Tarlov cyst. This case demonstrates the pathology clearly giving an excellent opportunity to demonstrate a rarely seen pathology as well as illustrating the importance of the patient history to guiding further management. CASE PRESENTATION: A middle-aged patient was admitted on the acute medical take complaining of severe headache with photophobia, having just returned after a skiing holiday. Computerised tomography scan of the head showed fat within the anterior horn of both lateral ventricles, and within the subarachnoid space. Re-discussion with the patient and subsequent MRI (Magnetic Resonance Imaging) of the spine identified the pathogenesis of her symptoms: a sacral insufficiency fracture through a Tarlov cyst, causing subarachnoid fat embolism and symptoms of a low-pressure headaches due to a dural leak. Patient was medically managed and discharged with planned follow-up. Due to the Coronavirus pandemic and resolution of the patient's symptoms, they declined further follow up imaging. CONCLUSIONS: The case demonstrates a rarely seen pathology as cause of a common presenting problem, headache. Emphasizing the importance of history taking and appropriate investigations in medical cases that do not conform to the usual diagnosis.

Pulmonary fat embolism: a potentially new fatal complication of SARS-CoV-2 infection. A case report.

BACKGROUND: So far, there have been more than 761 million confirmed cases of SARS-CoV-2 worldwide, with more than 6.8 million deaths. The most common direct causes of death for COVID-19 are diffuse alveolar injury and acute respiratory distress syndrome. Autopsy results have shown that 80-100% of COVID-19 patients have microthrombi which is 9 times higher than in patients with influenza. There are reported cases of fat embolism associated with Covid-19, but relevant epidemiological investigations and fatal cases of pulmonary fat embolism are lacking. In this report, we describe the first COVID-19 patient to die from pulmonary fat embolism. CASE PRESENTATION: A 54-year-old woman suddenly felt unwell while at work. She had difficulty breathing for 40 min and lost consciousness for 20 min before being taken to the hospital. On admission, her temperature was 36 ℃, but her respiration, heart rate, and blood pressure were undetectable. Laboratory examination revealed C-reactive protein, 26.55 mg/L; D-dimer, 11,400 µg/L; and procalcitonin, 0.21 ng/mL. She was declared clinically dead 2 h after admission due to ineffective rescue efforts. At autopsy, both lungs were highly oedematous with partial alveolar haemorrhage. The presence of microthrombi and pulmonary fat embolism in small interstitial pulmonary vessels was confirmed by phosphotungstic acid haematoxylin staining and oil red O staining. The immunohistochemical results of spike protein and nucleocapsid protein in laryngeal epithelial cells confirmed SARS-CoV-2 infection. CONCLUSIONS: Pulmonary fat embolism may be another fatal complication of COVID-19 infection, and clinicians should pay more attention to it.

Fat Embolism Syndrome Complicated by Diffuse Alveolar Hemorrhage After a Minimally Displaced Tibia Fracture: A Case Report.

CASE: A 26-year-old man with a minimally displaced tibial shaft fracture after an all-terrain vehicle crush injury rapidly developed fat embolism syndrome (FES), leading to diffuse alveolar hemorrhage (DAH) preoperatively. He was treated with an intramedullary rod 10 days after injury after a complicated clinical course and went on to full union with no long-term mental or systemic sequelae. CONCLUSIONS: FES is a known complication of long bone fractures, frequently presenting with hypoxemia. DAH is a rare complication of the condition. This case demonstrates the need for a high index of suspicion both for FES and DAH as complications of orthopaedic trauma.

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.

Rare, fatal pulmonary fat embolism after acupuncture therapy: A case report and literature review.

BACKGROUND: Death from nontraumatic pulmonary fat embolism associated with minor soft tissue contusion, surgery, cancer chemotherapy, hematologic disorders and so on has been reported. Patients often present with atypical manifestations and rapid deterioration, making diagnosis and treatment difficult. However, there are no reported cases of death from pulmonary fat embolism after acupuncture therapy. This case emphasizes that the stress induced by acupuncture therapy, a mild soft tissue injury, plays an important role in pulmonary fat embolism. In addition, it suggests that in such cases, pulmonary fat embolism as a complication of acupuncture therapy needs to be taken seriously, and autopsy should be used to identify the source of fat emboli. CASE PRESENTATION: The patient was 72 years old female and experienced dizziness and fatigue after silver-needle acupuncture therapy. She experienced a significant drop in blood pressure and died 2 h later despite treatment and resuscitation. A systemic autopsy and histopathology examination (H&E and Sudan Ⅲ staining) were performed. More than 30 pinholes were observed in the lower back skin. Focal hemorrhages were seen surrounding the pinholes in the subcutaneous fatty tissue. Microscopically, numerous fat emboli were observed in the interstitial pulmonary arteries and alveolar wall capillaries, in addition to the vessels of the heart, liver, spleen and thyroid gland. The lungs showed congestion and edema. The cause of death was identified as pulmonary fat embolism. CONCLUSION: This article suggests that high vigilance for risk factors and the complication of pulmonary fat embolism following silver-needle acupuncture therapy should be exercised. In postmortem examinations, it should be pay attention that the peripheral arterial system and the venous system draining from non-injured sites should be examined for the formation of fat emboli, which can help distinguish posttraumatic and nontraumatic pulmonary fat embolism.

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

OBJECTIVE: To observe the intervention effect of damage control orthopaedic(DCO) strategy on fat embolism syndrome(FES) associated with long shaft fracture of lower limbs. METHODS: Retrospective analysis was made on the clinical data of 163 patients with FES associated with lower limb long shaft fractures admitted from January 2015 to May 2021. They were divided into two groups based on the time point of implementing DCO strategy in January 2018. Total of 92 patients were admitted from January 2015 to December 2017 as the control group, and other 71 patients were admitted from January 2018 to May 2021 as the intervention group. The hospital mortality, arterial oxygen saturation (SaO2), arterial partial pressure of oxygen (PaO2) and oxygenation index (OI), hemoglobin (Hb), platelet count(PLT), Harris score of hip joint, HSS score of knee joint, AOFAS score of ankle joint, clinical efficacy and complications were observed and compared between two groups. RESULTS: Total of 163 patients were followed up for 12 to 18 months with an average of (16.91±1.22) months. The in-hospital mortality rate in the intervention group was 2.82% (2/71), and that in the control group was 16.30% (15/92), the difference between two groups was statistically significant(χ2=6.455, P<0.05). After the intervention, SaO2, PaO2 and OI in two groups were higher than those before the intervention(P<0.05), and after the intervention, SaO2, PaO2 and OI in two groups were statistically significant(P<0.05). Hb and PLT in two groups after intervention were higher than those before intervention (P<0.001), and there was statistically significant difference in Hb and PLT between two groups after intervention (P<0.05). The Harris score of hip joint, HSS score of knee joint and AOFAS score of ankle joint in both groups after 3 months of treatment were better than those before treatment (P<0.05). The total clinical effective rate of the intervention group was higher than that of the control group(χ2=4.194, P<0.05). The total incidence of complications in the intervention group was lower than that in the control group(χ2=4.747, P<0.05). CONCLUSION: DCO strategy is helpful to reduce the in-hospital mortality of patients with FES associated with long shaft fracture of lower extremities, eliminate FES symptoms and stabilize vital signs, gain time advantage for phase Ⅱ definitive surgery, and has significant clinical intervention effect, which is worth popularizing.