Fat embolism

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.

Successful Management of Intraoperative Acute Bilateral Pulmonary Embolism in a High Grade Astrocytoma Patient

Patient: Female, 39

Final Diagnosis: Acute bilateral pulmonary embolism

Symptoms: Headache • amnesia • seizure • urinary incontinence

Medication: —

Clinical Procedure: —

Specialty: Anesthesiology

Detection of pulmonary fat embolism with dual-energy CT: an experimental study in rabbits

OBJECTIVES

To evaluate the use of dual-energy CT imaging of the lung perfused blood volume (PBV) for the detection of pulmonary fat embolism (PFE).

METHODS

Dual-energy CT was performed in 24 rabbits before and 1 hour, 1 day, 4 days and 7 days after artificial induction of PFE via the right ear vein. CT pulmonary angiography (CTPA) and lung PBV images were evaluated by two radiologists, who recorded the presence, number, and location of PFE on a per-lobe basis. Sensitivity, specificity, and accuracy of CTPA and lung PBV for detecting PFE were calculated using histopathological evaluation as the reference standard.

RESULTS

A total of 144 lung lobes in 24 rabbits were evaluated and 70 fat emboli were detected on histopathological analysis. The overall sensitivity, specificity and accuracy were 25.4 %, 98.6 %, and 62.5 % for CTPA, and 82.6 %, 76.0 %, and 79.2 % for lung PBV. Higher sensitivity (p < 0.001) and accuracy (p < 0.01), but lower specificity (p < 0.001), were found for lung PBV compared with CTPA. Dual-energy CT can detect PFE earlier than CTPA (all p < 0.01).

CONCLUSION

Dual-energy CT provided higher sensitivity and accuracy in the detection of PFE as well as earlier detection compared with conventional CTPA in this animal model study.

KEY POINTS

• Fat embolism occurs commonly in patients with traumatic bone injury. • Dual-energy CT improves diagnostic performance for pulmonary fat embolism detection. • Dual-energy CT can detect pulmonary fat embolism earlier than CTPA.

Sudden death following accidental ingestion of a button battery by a 17-month-old child: a case study

Cases of ingesting button batteries by children are not common clinical situations in forensic medicine. Although it can be a cause of death when associated with digestive perforations, no cases of sudden death have been reported in the literature. We report the case of a 17-month-old girl who presented at home with haematemesis, followed by failed cardiopulmonary resuscitation. The child had been treated on two occasions for nasopharyngitis, 14 and 18 days prior to her death. The post-mortem scan revealed a radio-opaque foreign body in the oesophagus. The autopsy revealed the presence of a round button battery, 20 mm in diameter, blocking the lumen of the oesophagus in its upper third, associated with two parietal oesophageal ruptures opposite each other. There was limited digestive haemorrhage, but above all significant bronchial inhalation of blood. Toxicology analyses showed slightly increased blood levels of the heavy metals of which the battery was composed (lithium, chromium, manganese and molybdenum). The anatomopathological analyses confirmed the recent nature of these ruptures. Ingestions of button batteries localised at the level of the oesophagus are the cases linking to the highest risk of complications, particularly for batteries with a diameter of more than 20 mm and in children under the age of 4. The main difficulty in such clinical situations is identifying when the ingestion occurred, as more often than not, no witnesses are present. We discuss the advantages of anatomopathology and toxicology examinations targeted towards heavy metals in these forensic situations.

Hydrocephalus Caused by Fat Embolism: A Rare Complication of Atlanto-Axial Fixation for Odontoid Fractures

BACKGROUND AND IMPORTANCE

Odontoid fracture is not uncommon and surgical treatment that uses posterior screw/rod fixation is an acceptable option. This is the first report of delayed hydrocephalus due to subarachnoid fat migration as a complication of posterior atlanto-axial (AA) fixation.

CASE DESCRIPTION

A 27-year-old man underwent posterior C1 lateral mass and C2 pedicle screw fixation for a recent Anderson-D'Alonzo type 2 odontoid fracture. Autologous bone graft was wired for onlay fusion. The surgery was smooth, except that there was an incidental durotomy intraoperatively. The patient had significant relief of his neck pain, although computed tomography (CT) demonstrated a medial breach of the left C1 screw postoperation; however, he gradually developed headache and dizziness after discharge. Five weeks after operation, magnetic resonance imaging demonstrated a large pseudo-meningocele at the surgical site, which was managed conservatively. Nine weeks after the AA fixation, the patient was sent to the emergency department for altered consciousness. A brain CT demonstrated hydrocephalus and multiple fat emboli in the subarachnoid and intraventricular space. A ventriculoperitoneal shunt was inserted to manage the hydrocephalus and pseudo-meningocele. The patient recovered well and was followed up to 13 months after operation. To date, this was the first report of delayed hydrocephalus caused by fat embolism after AA fixation surgery.

CONCLUSIONS

Incidental durotomy in posterior AA fixation may predispose the patient to a serious complication of fat-cerebrospinal fluid embolism and subsequent hydrocephalus. There should be a heightened awareness for such a complication. Both CT and magnetic resonance imaging are useful for the diagnosis of subarachnoid fat droplets.

Fat embolism syndrome: State-of-the-art review focused on pulmonary imaging findings

BACKGROUND

Fat embolism syndrome (FES) is a rare but potentially fatal complication of trauma or orthopedic surgery, which presents predominantly with pulmonary symptoms. Modern intensive care has improved the mortality rates, however diagnosis remains difficult, relying predominantly on a combination of a classic triad of symptoms and non-specific, but characteristic radiological features. The aim of this review is to describe the main clinical and imaging aspects of FES, ranging from pathophysiology to treatment with emphasis on pulmonary involvement.

METHODS

We reviewed the currently published literature on the main characteristics of FES.

RESULTS

In a hypoxic patient with recent trauma or orthopedic surgery, the presence of diffuse, well-demarcated ground glass opacities or ill-defined centrilobular nodules on computed tomography (CT) of the chest are suggestive of FES.

CONCLUSIONS

Combination of the classic clinical syndrome in the appropriate clinical setting, together with the characteristic imaging findings on chest CT, can help to achieve the correct diagnosis. Management remains predominantly supportive care, and the benefit of medical therapies such as corticosteroids and heparin remains unclear.

Massive cerebral fat embolism leading to brain death: A rare presentation

Fat embolism syndrome (FES) typically consists of a triad of neurological, pulmonary, and cutaneous symptoms. There exist few case reports of FES involving central nervous system (CNS) only without pulmonary involvement. In most of such cases, CNS involvement is partial, and patients recover fully neurologically within days. We report a rare and unusual case of massive cerebral fat embolism that led to brain death in trauma patient.

Non-infectious Parenchymal Lung Disease

Acute dyspnea is a common presenting complaint in the emergency room, emergency medicine and intensive care. It may have a cardiovascular or a non-cardiovascular origin, the latter including pulmonary parenchymal diseases. Depending on the cause, it may be associated with fever, cough, hemoptysis, and/or chest pain, with a duration of symptoms that can range from hours to days.

Prompt identification of the underlying cause of acute dyspnea is essential in guiding appropriate therapy and management, as patients may rapidly progress to acute respiratory failure. Evaluation with chest radiography is vital for initial assessment and may reveal diffuse parenchymal abnormalities, which may require further assessment with computed tomography (HRCT).

Acute non-infectious parenchymal lung diseases are often overlooked and may be under-diagnosed. Their diagnosis requires the evaluation, along with the HRCT pattern, of the clinical and laboratory features and of the bronchoalveolar lavage. Biopsy may be necessary in more complex cases.

Although the most frequent cause of diffuse non-infectious parenchymal lung involvement is acute hydrostatic pulmonary edema, there is a wide variety of diseases that may be encountered, including acute drug toxicity, hypersensitivity pneumonitis (HP), acute respiratory distress syndrome (ARDS) and diffuse alveolar hemorrhage (DAH). In trauma patients, fat embolism syndrome (FES) must be taken into account. Acute respiratory failure is an eventuality that can occur during the course of chronic lung diseases (UIP for example), which may have been unknown until then.

Donor-acquired fat embolism syndrome after lung transplantation

OBJECTIVES

Fat embolism is a known complication of severe trauma and closed chest cardiac resuscitation both of which are more common in the lung transplant donor population and can lead to donor-acquired fat embolism syndrome (DAFES). The objective was to review the diagnosis and management of DAFES in the lung transplantation literature and at our centre.

METHODS

We performed a literature review on DAFES using the Medline database. We then reviewed the transplant record of Brigham and Women's Hospital, a large academic hospital with an active lung transplant programme, for cases of DAFES.

RESULTS

We identified 2 cases of DAFES in our centre, one of which required extracorporeal membrane oxygenation (ECMO) for successful management. In contrast to the broader literature on DAFES, which emphasizes unsuccessfully treated cases, both patients survived.

CONCLUSION

DAFES is a rare but likely underappreciated early complication of lung transplant as it can mimic primary graft dysfunction. Aggressive interventions, including ECMO, may be necessary to achieve a good clinical outcome following DAFES.

A Case of Acute Fulminant Fat Embolism Syndrome after Liposuction Surgery

Fat embolism syndrome (FES) is a clinical manifestation that consists of multiple organ dysfunction due to fat emboli. FES occurs as a complication after trauma or procedures such as surgery. The diagnostic criteria of FES have not yet been established, so clinical criteria are used for its diagnosis. The clinical course of acute fulminant FES can be rapid. Liposuction surgery, in which adipocytes are mechanically disrupted, is one cause of FES. As the number of liposuction surgeries increases, clinicians should be aware of the possibility of FES. This was the first report of a case of acute fulminant FES with severe acute respiratory distress syndrome after liposuction surgery, in Korea.

Fat embolism after liposuction in Klippel-Trenaunay syndrome

Fat embolism syndrome (FES) is a rare but potentially fatal postoperative complication from liposuction. We present the case of a 24-year-old woman with Klippel-Trenaunay syndrome who developed FES as a complication of lower extremity liposuction. There may be an increased risk of FES in patients with vascular malformations undergoing liposuction.

Inflammatory responses to neutral fat and fatty acids in multiple organs in a rat model of fat embolism syndrome

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

Concomitant fat embolism syndrome and pulmonary embolism in a patient with a femoral shaft fracture

Case

A 22-year-old man was injured in a traffic accident and developed respiratory distress on his first day of admission. On postadmission day 3, he developed serious respiratory distress with a suddenly altered mental status. Chest computed tomography revealed a pulmonary embolism that had not been evident when he was admitted. The patient was intubated and a continuous heparin infusion was started to treat the pulmonary embolism. Palpebral conjunctival petechiae were noticed the following day, at which point the patient fulfilled Gurd's criteria for fat embolism syndrome. Within a few days, his respiratory status was improved. Brain magnetic resonance imaging also provided evidence of fat embolism syndrome. His femoral shaft fracture was repaired on day 20.

Outcome

The patient was discharged home on postadmission day 63.

Conclusion

Concomitant fat embolism syndrome and pulmonary embolism, although very rare, should be considered when a trauma patient's respiratory status worsens.

Does intramedullary canal irrigation reduce fat emboli? A randomized clinical trial with transesophageal echocardiography

The effect of medullary cavity irrigation on fat emboli during total knee arthroplasty (TKA) was evaluated. Thirty female patients with osteoarthritis were randomly assigned to undergo conventional TKA without irrigation (conventional group) or with medullary canal saline irrigation (irrigation group). The four-chamber view was monitored by transesophageal echocardiography (TEE) and echogenic reflections of fat emboli were observed. The grey-scale score and area ratio of fat emboli were calculated during TKA. Hemodynamic parameters were simultaneously monitored and showed no obvious change between two groups (P>0.05). The average grey-scale score (P=0.016) and area ratio (P=0.033) of emboli were significantly decreased in irrigation group. Removal of medullary contents by irrigation could significantly reduce the formation of fat emboli during TKA.

Fat Intravasation from Intraosseous Flush and Infusion Procedures

STUDY HYPOTHESIS

The primary study objective was to delineate the procedural aspects of intraosseous (IO) infusions responsible for fat intravasation by testing the hypothesis that the fat content of effluent blood increases during IO infusions.

METHODS

IO cannulas were inserted into the proximal tibiae of 35 anesthetized swine (Sus scrofa, 50.1 ± 3.5 kg) and intravasated fat was assessed using a lipophilic fluoroprobe (Nile red) and by vascular ultrasound imaging. Effluent blood bone marrow fat was assessed at baseline, during flush, and with regimens of controlled infusion pressures (73-300 mmHg) and infusion flow rates (0.3-3.0 mL per second). Fat intravasation was also assessed with IO infusions at different tibial cannulation sites and in the distal femur. In 7 animals, the lipid uptake of alveolar macrophages and lung tissue assessed for fat embolic burden using oil red O stain 24 hours post infusion. Additionally, bone marrow shear-strain was assessed radiographically with IO infusions.

RESULTS

Fat intravasation was observed during all IO infusion regimens, with subclinical pulmonary fat emboli persisting 24 hours post infusion. It was noted that initial flush was a significant factor in fat intravasation, low levels of intravasation occurred with infusions ≤300 mmHg, fat intravasation and bone marrow shear-strain increased with IO infusion rates, and intravasation was influenced by cannula insertion site. Ultrasound findings suggest that echogenic particles consistent with fat emboli are carried in fast and slow venous blood flow fields. Echo reflective densities were observed to rise to the nondependent endovascular margins and coalesce in accordance with Stoke's law. In addition, ultrasound findings suggested that intravasated bone marrow fat was thrombogenic.

CONCLUSION

Results suggest that in swine the intravasation of bone marrow fat is a common consequence of IO infusion procedures and that its magnitude is influenced by the site of cannulation and infusion forces. Although the efficacy and benefits of IO infusions for emergent care are well established, emergency care providers also should be cognizant that infusion procedures affect bone marrow fat intravasation.

Peri-operative massive pulmonary embolism management: is veno-arterial ECMO a therapeutic option?

Pulmonary embolism remains an important clinical problem with a high mortality rate. The potential for sudden and fatal hemodynamic deterioration highlights the need for a prompt diagnosis and appropriate intervention. The purpose of the present case report is to describe a successful peri-operative veno-arterial extra corporeal membrane oxygenation (VA-ECMO) implantation for assumed massive pulmonary embolism associated with high hemodynamic instability and severe hypoxemia. A 52-year-old female victim of a motorcycle accident had been operated on for unstable fractures that required optimal repair. Despite subcutaneous administration of 40 mg enoxaparin on day 0 and day 1, the patient developed a massive pulmonary embolism leading to peri-operative pulseless activity. As intravenous thrombolysis was strictly contraindicated, a VA-ECMO was successfully implanted and permitted to stabilize the patient's hemodynamics. The hemodynamic and respiratory status improved by day 3, and the ECMO was removed. A vena cava filter was implanted before successful and definitive stabilization of the femoral fracture and the L2 fracture on days 4 and 5. The patient was able to be mobilized 2 days after the surgery and was transferred to a rehabilitation ward on day 15. At that time, her cognitive functions had fully recovered. ECMO can provide lifesaving hemodynamic and respiratory support in patients with massive pulmonary embolism who are too unstable to tolerate other interventions, who have failed other therapies or for whom other therapies are contraindicated.

Fat embolism syndrome: Case report of a clinical conundrum

Fat embolism syndrome is a rare clinical condition associated with trauma, particularly of long bones. FES after fracture of neck of femur or head of humerus is uncommon. We report a case of FES following fracture in neck of femur and head of humerus in a man with history of mitral valve replacement, on long-term oral anticoagulant therapy, with an alleged history of convulsions. Our dilemma in clinical diagnosis is discussed.

High-dose rosuvastatin treatment for multifocal stroke in trauma-induced cerebral fat embolism syndrome: a case report

BACKGROUND

Fat embolism syndrome is a life-threatening condition with treatment centering on the provision of excellent supportive care and early fracture fixation. No pharmacologic intervention has yet shown any clear benefit. We used high-dose rosuvastatin specifically for its anti-inflammatory effects to treat a patient with severe fat embolism syndrome. We also suggest that magnetic resonance imaging and transcranial Doppler studies are helpful in establishing the diagnosis and for monitoring the patient's course.

PATIENT

A 17-year-old boy developed severe cerebral fat embolism syndrome with multifocal strokes after sustaining bilateral femur fractures.

RESULTS

In spite of profound and prolonged neurological impairment, our patient experienced dramatic recovery by the time he was discharged from inpatient rehabilitation several weeks after his initial injury. Magnetic resonance imaging revealed the classic "starfield" pattern of infarcts on diffusion-weighted sequences early in the illness. Additionally, serial transcranial Doppler studies demonstrated dramatically elevated microembolic events that resolved completely during the course of treatment.

CONCLUSION

We feel that the acute administration of high-dose rosuvastatin early in the development of our patient's illness may have contributed to his ultimate recovery. Therapeutic guidelines cannot be extrapolated from a single patient, but our experience suggests that statin therapy could be potentially beneficial for individuals with severe fat embolism syndrome, and this approach deserves further clinical evaluation. Additionally, the diagnosis and monitoring of cerebral involvement in fat embolism syndrome is facilitated by both magnetic resonance imaging and transcranial Doppler studies.

[A case of cerebral fat embolism after artificial bone replacement operation for femoral head fracture]

A 83 years old woman was slipped and injured with right femoral neck fracture. After three days from the fracture, she underwent an artificial head bone replacement operation. Immediately after surgery, she complained of chest discomfort, nausea and dyspnea. A few hours later, she became comatose. Brain CT showed no abnormality and clinical diagnosis of heart failure was made without pulmonary embolism on enhanced chest CT. Magnetic resonance imaging (MRI) of the brain next day showed multiple small patchy hyperintense lesion in bilateral hemispheres on diffusion-weighted images (DWI), producing a "star field pattern''. Based on Criteria of Gurd, this patient had one major criterion and four minor criteria. And according to the Criteria of Schonfeld, this patient had 5 points, consistent with clinical diagnosis of fat embolism. Because of these criteria, she was diagnosed as cerebral fat embolism syndrome. We started supported care and edaravon. Two weeks after surgery, her condition recovered and remaind to stuporous state even six month after surgery. We experienced a typical case of cerebral fat embolism, after bone surgery with diagnostic findings on MRI-DWI. Diagnosis of cerebral fat embolism syndrome requires a history of long bone fracture and/or replacing surgery with typical finding on MRI images, such as "star field pattern''.

Paradoxical cerebral fat embolism in revision hip surgery

The incidence of clinical fat embolism syndrome (FES) is low (<1%) whilst fat embolism (FE) of marrow fat appears to occur more often (Mellor and Soni (2001)). Paradoxical brain FE may occur in patients undergoing hip orthopedic surgery who have an undocumented patent foramen ovale (PFO). We report a case of an eighty-year-old male patient, who underwent a scheduled revision hip surgery suffering a paradoxical cerebral FE.

Use of early inhaled nitric oxide therapy in fat embolism syndrome to prevent right heart failure

Fat embolism syndrome (FES) is a life-threatening condition in which multiorgan dysfunction manifests 48–72 hours after long bone or pelvis fractures. Right ventricular (RV) failure, especially in the setting of pulmonary hypertension, is a frequent feature of FES. We report our experience treating 2 young, previously healthy trauma patients who developed severe hypoxemia in the setting of FES. Neither patient had evidence of RV dysfunction on echocardiogram. The patients were treated with inhaled nitric oxide (NO), and their oxygenation significantly improved over the subsequent few days. Neither patient developed any cardiovascular compromise. Patients with FES that have severe hypoxemia and evidence of adult respiratory distress syndrome (ARDS) are likely at risk for developing RV failure. We recommend that these patients with FES and severe refractory hypoxemia should be treated with inhaled NO therapy prior to the onset of RV dysfunction.

Transposition of intravascular lipid in experimentally induced fat embolism: a preliminary study

BACKGROUND

Liposuction is a procedure to reduce the volume of subcutaneous fat by physical force. Intracellular storage fat is composed of triglyceride, whereas circulating fat particles exist as cholesterol or triglycerol bound to carrier proteins. It is unavoidable that the storage form of fat particles enters the circulation system after these particles are physiologically destroyed. To date, however, no studies have clarified the fatal characteristics of fat embolism that occurs after the subclinical phase of free fat particles.

METHODS

A mixture of human lipoaspirate and normal saline (1:100, 0.2 mL) was injected into the external jugular vein of rats, weighing 200 g on average. Biopsy specimens of the lung and kidney were examined at 12-hour intervals until postoperative 72 hours. The deposit location and transport of the injected free fat particles were confirmed histologically by an Oil Red O stain.

RESULTS

Inconsistent with previous reports, free fat particles were transported from the intravascular space to the parenchyma. At 24 hours after infusion, free fat particles deposited in the vascular lumen were confirmed on the Oil Red O stain. At 72 hours after infusion, free fat particles were accumulated compactly within the parenchymal space near the perivascular area.

CONCLUSIONS

Many surgeons are aware of the fatal results and undiscovered pathophysiologic mechanisms of free fat particles. Our results indicate that free fat particles, the storage form of fat that has been degraded through a physiological process, might be removed through a direct transport mechanism and phagocytotic uptake.

Magnetic resonance imaging of traumatic brain injury: a pictorial review

Traumatic brain injury (TBI) is a significant source of major morbidity and mortality in blunt trauma patients. Computed tomography (CT) is the primary imaging modality of choice for patients with potential brain injury in the acute setting, with magnetic resonance imaging (MRI) playing a role in evaluating equivocal CT findings and may help with determining long-term prognosis and recovery. MRI is being utilized more commonly in the acute and subacute setting of TBI; therefore, radiologists should be familiar with the MRI appearance of the various manifestations of TBI. Here, we review the imaging of common intracranial injuries with illustrative cases comparing CT and MRI.

Autopsy diagnosis of fat embolism syndrome

The fat embolism syndrome (FES) is considered a clinical diagnosis. It typically occurs within several days following major traumatic injury, usually involving fractures of the pelvis and/or lower extremities. Fat embolism syndrome is characterized by the onset of respiratory, neurological, cutaneous, and hematologic manifestations and is thought to be related to intravascular embolization of fat, presumably arising from within the fractured bone marrow space. In its most severe form, FES can be lethal. The presence of fat emboli within the microvasculature of the lungs, brain, and sometimes other organs verifies the clinical impression of FES. Despite its relatively well-known clinical characterization, debate exists within the clinical literature regarding the most appropriate diagnostic criteria for FES. Given this fact, along with the fact that FES is a clinical diagnosis, it is not surprising that forensic pathologists may be somewhat reluctant to make a postmortem diagnosis of FES, especially in cases where insufficient clinical information is available. A case of fatal FES is presented in which rapid clinical deterioration occurred, followed by death, such that a clinical diagnosis of FES was never rendered. We propose that, given the correct circumstances, clinical scenario, and autopsy findings, it is appropriate and acceptable to make a postmortem diagnosis of FES. A multitiered approach to the postmortem diagnosis of FES is presented.

Favorable outcome of cerebral fat embolism syndrome with a glasgow coma scale of 3: a case report and review of the literature

Prognosis of deep coma caused by cerebral fat embolism syndrome (CFES) is rarely reported. We present a case of fulminant CFES which was induced by long bone fracture, with a Glasgow Coma Scale (GCS) of 3/15. The brain magnetic resonance imaging (MRI) revealed abnormal spotty lesions scattered over both cerebral hemispheres and the posterior fossa. Thirty days later, the patient regained consciousness with a GCS of 15/15.

Purtscher's retinopathy after intramedullary nailing of a femoral shaft fracture in a 20-year old healthy female - report of a rare case and review of the literature

Background

Purtscher’s retinopathy is a sight threatening, occlusive microvasculopathy associated with trauma, it is rarely reported after long bone fractures.

Case presentation

A 20-year-old female sustained a femoral shaft fracture (AO 32-A2.3) in a ski accident colliding with a snowgun and was treated with intramedullary nailing one hour after the accident. 14 hours after surgery the patient complained of loss of vision in both eyes and was therefore referred to a neurologist, furthermore an MRI scan of the brain was performed. Neither showed any pathological findings. The patient was finally transferred to an ophthalmology department. After slit lamp examination and funduscopy Purtscher’s retinopathy was diagnosed. Treatment was started right after diagnosis and 5 days after the onset of symptoms. The patient was administered intravenous haemo-rheologic therapy for five days as well as low molecular heparine in therapeutic dose and Vasonit® 400 mg bid orally.

At follow-up 4 weeks and 6 months later visual acuity had improved after 4 weeks before that exam. At final follow-up the symptoms had almost resolved completely and uncorrected visual acuity (UCVA) and best corrected visual acuity had improved from originally 0.25 decimal in both eyes to 0.8 decimal UCVA and BCVA in both eyes.

Conclusions

Patients suffering from perioperative loss of vision have to be referred for ophthalmological and neurological assessment as soon as possible. History of trauma and visual loss can point to the diagnosis of Purtscher’s retinopathy.

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

A traumatic case of fat embolism

A fit and healthy 47-year-old woman developed type I respiratory failure 2 days following surgical fixation for a left intertrochanteric neck of femur fracture. She presented to the acute trauma unit following a fall off a horse and had a long dynamic hip screw fixation in theatre. Postoperatively, she became confused and hypoxic. Her chest X-ray was inconclusive and her CT pulmonary angiogram showed diffuse patchy ground glass shadowing in keeping with acute respiratory distress syndrome. Following review by intensive care and respiratory physicians, a diagnosis of acute lung injury secondary to fat embolism was reached. The patient made a good recovery on the orthopaedic ward with supportive treatment.

Alveolar hemorrhage in a case of fat embolism syndrome: A case report with short systemic review

Fat embolism and fat embolism syndrome (FES) are well-known complications of long bone fracture and surgery involving manipulation of skeletal elements. Many non-traumatic causes of FES have been suggested but they constitute only a small portion. FES presents with classical symptoms of petechiae, hypoxemia, central nervous system symptoms along with other features such as tachycardia and pyrexia. Diagnosis of FES relies on clinical judgment rather than objective findings such as emboli present in the retinal vessels on fundoscopy, fat globules present in urine and sputum, a sudden inexplicable drop in hematocrit or platelet values, increasing erythrocyte sedimentation rate.

Pulmonary fat embolism and related effects during femoral intramedullary surgery: An experimental study in dogs

The aim of the present study was to develop an animal model of pulmonary fat embolism (PFE) caused by femoral intramedullary procedures, and to investigate the initial changes in the hemodynamics, cytokines and risk factors of PFE. Sixteen dogs were randomly divided into two groups: Group A (intramedullary reaming and bone cement injection, n=8) and Group B (surgical approach without opening the medullary cavity, n=8). The hemodynamics, arterial blood gases and relevant cytokines were evaluated, and the lungs were examined using Oil Red O staining. In the animals of Group A, the heart rate, central venous pressure, mean pulmonary arterial pressure, pulmonary capillary wedge pressure and extravascular lung water (EVLW) were increased compared with the baseline levels, while the mean arterial pressure was decreased immediately following the reaming and bone cement infusion (P<0.05). Furthermore, there was a significant reduction in the pH and the arterial oxygen tension (PaO₂), and a significant increase in the arterial carbon dioxide tension (PaCO₂; P<0.05 for all) following the bilateral intramedullary surgery. The EVLW was correlated with the PaO₂ (P<0.001) and PaCO₂ (P=0.046). Following surgery, there was a significant increase in tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6 levels in Group A (P<0.05). However, there were no significant changes in these parameters in Group B. The parameters tested, with the exception of pH, were significantly different in Group A compared with those in Group B (P<0.05) following the bilateral intramedullary surgery. Oil Red O staining was positive for all animals in Group A and negative for those in Group B. Femoral intramedullary surgery may induce PFE and subsequently affect hemodynamics and arterial blood gases. EVLW was correlated with the PaO₂ (P<0.001) and the PaCO₂ (P=0.046). These results demonstrated that EVLW and cytokines may serve as predictors of the development of fat embolism syndrome (FES).

Fatal Systemic Embolism following Revision of Hip Arthroplasty: A Complication of Pulmonary Arteriovenous Malformation

A 72-year-old female patient who had a pulmonary arteriovenous malformation (PAVM) suffered systemic emboli causing pulmonary and cerebral infarction following the revision of an infected total hip replacement. Although not ultimately successful in this case, we detail the management of maintaining oxygenation and adequate cardiac output in a critically ill patient with a PAVM. We also discuss techniques that may be employed to minimise the shunt associated with the PAVM, with the aim of reducing the risk of systemic emboli.

Fat embolism syndrome in long bone trauma following vehicular accidents: Experience from a tertiary care hospital in north India

BACKGROUND

Fat embolism syndrome (FES) is a clinical problem arising mainly due to fractures particularly of long bones and pelvis. Not much literature is available about FES from the Indian subcontinent.

MATERIALS AND METHODS

Thirty-five patients referred/admitted prospectively over a 3-year period for suspected FES to a north Indian tertiary care center and satisfying the clinical criteria proposed by Gurd and Wilson, and Schonfeld were included in the study. Clinical features, risk factors, complications, response to treatment and any sequelae were recorded.

RESULTS

The patients (all male) presented with acute onset breathlessness, 36-120 hours following major bone trauma due to vehicular accidents. Associated features included features of cerebral dysfunction (n = 24, 69%), petechial rash (14%), tachycardia (94%) and fever (46%). Hypoxemia was demonstrable in 80% cases, thrombocytopenia in 91%, anemia in 94% and hypoalbuminemia in 59%. Bilateral alveolar infiltrates were seen on chest radiography in 28 patients and there was evidence of bilateral ground glass appearance in 5 patients on CT. Eleven patients required ventilatory assistance whereas others were treated with supportive management. Three patients expired due to associated sepsis and respiratory failure, whereas others recovered with a mean hospital stay of 9 days. No long term sequelae were observed.

CONCLUSION

FES remains a clinical challenge and is a diagnosis of exclusion based only on clinical grounds because of the absence of any specific laboratory test. A high index of suspicion is required for diagnosis and initiating supportive management in patients with traumatic fractures, especially in those having undergone an invasive orthopedic procedure.

Delayed recovery of spontaneous circulation following cessation of cardiopulmonary resuscitation in an older patient: a case report

Introduction

This report describes the apparent ‘resurrection’ of a patient in an emergency department setting. Befittingly named the ‘Lazarus phenomenon’, the recovery of spontaneous circulation after cessation of cardiopulmonary resuscitation is an extremely rare occurrence that was first described in 1982 and has been mentioned only 38 times in the medical literature. Our patient’s case is remarkable in that it helps illustrate many of the mechanisms of this rare phenomenon. It also serves as a reminder of our limitations in determining when to terminate cardiopulmonary resuscitation and suggests that cessation of cardiopulmonary resuscitation should be approached with more care.

Case presentation

An 89-year-old Caucasian woman with a medical history of hypertension, atrial fibrillation, hypothyroidism, aortic insufficiency, lymphedema and hypoxia secondary to partial lung resection presented to our hospital after a witnessed fall unassociated with head trauma or loss of consciousness. On examination, our patient was saturating at 85 percent and exhibited a decreased range of motion of the upper extremities and left hip. Radiographic images revealed a left femoral neck and left distal radius fracture. Our patient was stabilized on 100 percent fraction of inspired oxygen and was awaiting transfer to an in-patient unit when, at 3:30 a.m., she went into cardiac arrest. An advanced cardiac life support protocol was initiated, at which time our patient was intubated and administered epinephrine, vasopressin and sodium bicarbonate. Our patient remained unresponsive and asystolic so cardiopulmonary resuscitation was abandoned at 3:48 a.m. After five minutes a ventricular contraction was noted at 3:51 a.m. This progressed to sinus rhythm with a pulse at 3:53 a.m. Our patient was stabilized on norepinephrine and moved to our Intensive Care Unit. At 10:55 a.m., however, our patient again arrested and, despite resuscitative efforts, was pronounced dead at 11:03 a.m.

Conclusions

Our patient’s case clearly illustrates many of the proposed mechanisms for delayed return of spontaneous circulation including pulmonary hyper-inflation, hyperkalemia, delayed drug onset, and embolism dislodgement. Our patient represents a humbling and disturbing reminder that our medical acumen does not necessarily dictate the fate of our patients and that the decision to discontinue cardiopulmonary resuscitation should be approached with care by incorporating techniques such as end-tidal carbon dioxide, ventilator disconnect and passive monitoring.

Fat embolism syndrome

Fat embolism syndrome is an often overlooked cause of breathlessness in trauma wards. Presenting in a wide range of clinical signs of varying severity, fat embolism is usually diagnosed by a physician who keeps a high degree of suspicion. The clinical background, chronology of symptoms and corroborative laboratory findings are instrumental in a diagnosis of fat embolism syndrome. There are a few diagnostic criteria which are helpful in making a diagnosis of fat embolism syndrome. Management is mainly prevention of fat embolism syndrome, and organ supportive care. Except in fulminant fat embolism syndrome, the prognosis is usually good.

[Fat embolism syndrome after bone fractures]

OBJECTIVES

To review the incidence, clinical features, diagnosis, therapy and mortality rates of fat embolism syndrome (FES) in a tertiary referral hospital in the last decade.

PATIENTS AND METHODS

Retrospective and descriptive study of patients diagnosed with post-traumatic FES between january 2001 and december 2011.

RESULTS

A total of 19 patients, 16 men and 3 women, with an average age of 27 years were evaluated. All had long bone fractures, multiple in 78.9%, as a result of multiple injuries. Respiratory symptoms were the most frequent (89.5%), followed by neurological symptoms (68.4%) and petechial rash (63.2%). The average time of presentation of the syndrome after admission was 42 hours. All patients underwent early stabilisation of the fracture prior to the embolic event. Steroids prophylaxis was not used in any of the cases. Definitive surgical treatment had mean delay of 7 days. The mean hospital stay was 34 days. The overall incidence of FES was 0.14%, and mortality was 10.5%.

CONCLUSIONS

Post-traumatic FES mainly affected young patients with multiple injuries and long bone fractures. They all had symptoms of the classic clinical triad (respiratory, neurological, rash) after an initial asymptomatic period of less than 2 days. The overall incidence was low.