Clinical Fat Embolism Syndrome Research Articles

Is There Any Role of Inhalational Corticosteroids in the Prophylaxis of Post-Traumatic Fat Embolism Syndrome?

Fat embolism syndrome (FES) is primarily a lung parenchymal disorder resulting from interstitial and alveolar inflammation triggered by the lipid metabolites in blood circulation. The 'low-dose' corticosteroid is supposed to have a prophylactic effect on the incidence of the FES and arterial hypoxemia by reducing this inflammatory response. It is expected that inhaled corticosteroids (ciclesonide aerosol) may prevent the development of hypoxemia or fat embolism syndrome in high-risk patients by reducing this inflammatory response. Metered-dose inhaler (MDI) steroid preparations can reach the lung parenchyma with minimal systemic effect. Sixty cases of polytrauma patients presenting within eight hours of injury were randomly allocated into one of the two groups. In Group 1 (n1=30) ciclesonide, 640 mcg, was given with a metered dose inhaler and repeated once again after 24 hours, whereas Group 2 (n2=30) was taken as control and observed for 72 hours for any episode of hypoxia. The outcome was assessed using Schonfeld’s criteria for the eventual outcome of subclinical or clinical FES. Out of 30 patients in each group, six patients developed subclinical FES, whereas three from ciclesonide prophylaxis group and eight from controls developed clinical FES. There is no statistical significance found between the eventual outcomes of subclinical or clinical FES between the ciclesonide prophylaxis and control group. Although there was a trend seen in the possible preventive efficacy of inhalational steroid in the present study, it did not reach the statistically significant level. The prophylactic role of inhalational steroid in post-traumatic subclinical and clinical FES is statistically insignificant in the present study.

Multiorgan dysfunction due to traumatic fat embolism syndrome: Critical care and perioperative issues

Fat embolism is the presence of fat droplets within the circulation following trauma with or without clinical sequel. Fat embolism syndrome (FES) is a rare, but serious sequel of fat embolism usually occurring within 24 h of trauma and mostly causing petechial rashes, respiratory insufficiency, and central nervous system dysfunction. We report a young male who developed clinical FES while awaiting surgery for definitive fixation of bilateral closed tibial fracture following initial stabilization with long leg slab, was treated in the intensive care unit and underwent internal fixation under epidural anesthesia after clinical improvement. FES is a multisystem disorder with variable clinical presentation. Timely organ support improves prognosis. Epidural anesthesia can be a safe option for definitive fixation of lower limb fractures after improvement of organ dysfunctions.

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.

Hemorrhage in cerebral fat embolisms in a cat model using triolein dependent on the physical properties of triolein

Hemorrhage is a finding of clinical fat embolism syndrome. The purpose of the present study was to evaluate the occurrence of hemorrhage in the cat brain by SW MR imaging after infusion of triolein as a bolus or as an emulsion into the carotid artery. Twenty-two cats were divided into two groups according to the type of triolein infused: group 1 (n = 11) was infused with a 0.1 ml triolein bolus, group 2 (n = 11) with triolein emulsion containing 0.1 ml triolein in 20 ml saline. SW imaging was performed before and after triolein infusion (at 2 h, 1 and 4 days). After MR imaging on day 4, cats were sacrificed and brains were immediately excised. Hemorrhage was evaluated using H&E staining. Hemorrhage was observed in eight cats in group 1, in no cats in group 2. Hemorrhage on SW images was found to correspond with light microscopy. SW images revealed hemorrhage in lesion hemispheres infused with triolein bolus. However, there was no evidence of hemorrhage infused with emulsified triolein. Thus, the occurrence of hemorrhage in cerebral fat embolism may depend on fat status.

Fat embolus in femur fractures: a comparison of two reaming systems

Objective To measure the amount of fat presented to the right heart during reaming and nail placement using two different reamer systems. Design Prospective, randomized clinical trial. Setting University-based Level I Trauma Center. Patients 20 patients with femur fractures. Intervention Patients with femur fractures were treated with intramedullary nailing using either reamer-irrigator-aspirator or a conventional reamer. Main Outcome Measure four-chamber trans-esophageal echocardiogram was used to quantify the amount of fat presented to the right atrium. Results There were 2 female and 18 male patients enrolled, 10 in each group. There was no significant difference (p=0.10) between reaming systems on the opening reamer, which was expected since both trial limbs used the same opening reamer. However, during the first pass of the reamer, the RIA showed a nearly-significant decrease in the volume of fat in the right atrium (p=0.06). During passage of the nail, there was a significant difference with Group B having less fat embolus than Group A (p=0.01). The power of this study is 0.81. The mean ISS was not significantly different between the two groups, nor was the sex, age or race. There was one death from cardiac complications in a patient who showed no fat during any phase of the procedure. This patient had significant mitral and aortic regurgitation pre-operatively. There was one patient with clinical fat embolism syndrome and one patient with a nonunion. Conclusions There is a statistically significant difference in the amount of fat presented to the lungs using a RIA versus conventional reamer.

CD61 and fibrinogen immunohistochemical study to improve the post-mortem diagnosis in a fat embolism syndrome clinically demonstrated by transesophageal echocardiography

Fat embolization following major trauma is reported to be a quite common event, while the clinical fat embolism syndrome (FES) seems to be a much rarer event. Fat embolism occurs in 2 up to 23% of patients with isolated femoral shaft fractures. This complication appears to be related not only to the fracture, but also to the timing of stabilization. Sometimes it may be impossible to perform histochemical reactions on frozen sections to detect fat emboli thus confirming diagnosis or suspicion of FES. The finding of fibrinogen and platelets around the apparently empty spaces in the blood vessels has been proposed as an evidence for vital reaction due to either a vital cellular reaction or a flotation mechanism, thus supporting an intravital fat embolism. We report a fatal case due to fat embolism syndrome in a young man hospitalized for a right femoral neck fracture, treated with orthopaedic surgery and subjected to an intra-surgery transesophageal echocardiography that revealed embolization of numerous highly echogenic bodies. Four hours after the onset of clinical symptoms the man died from respiratory failure. The autopsy confirmed the clinical diagnosis of fat embolism syndrome. The histological examination revealed a large amount of fat globules in cerebral and pulmonary arteries and in glomerular capillaries, as well as fibrin and platelet deposition confirmed by the positive results by Sudan III staining for lipids and immunohistochemistry with anti-CD61 and anti-fibrinogen antibodies. The quantitative classification of fat embolism was grade 3 of Sevitt's classification or grade 4 of Fineschi's quantification, according to the current quantitative microscopic methods used for grading fat embolism in pulmonary tissue.

Fat Embolism in Patients with Multiple Injuries

Of 459 patients treated in the intensive care unit (ICU) from 1975 - 1978, 211 patients with multiple injuries and fractures of the long bones and pelvis / spine were treated emergently using internal fixation in a primary stage. The main outcome of interest was clinical fat embolism syndrome (grade III), a severe and potentially life-threatening condition that is common following long-bone and pelvic fractures. Early operative fixation resulted in a low rate of grade III fat embolism and, therefore, may effectively prevent subsequent morbidity and mortality in this patient population.

Effect of Fat Embolism with Triolein Emulsion on Blood-Retinal Barrier

Background: Triolein emulsion is under investigation for supplemental use to open the blood-brain barrier during chemotherapy. The effects of triolein emulsion on the blood-retinal barrier (BRB) were investigated. Methods: Fat emboli were induced in 20 cats by injecting triolein emulsion through the carotid artery. At 30 min, 4, 12 and 48 h after embolization, electroretinography (ERG) and fluorescein angiography (FA) were performed. The eyeballs were enucleated for transmission electron-microscopic study. Results: FA revealed multiple leaking points at 30 min, and prominent diffuse leakage at 4 h when scotopic b-waves showed significant differences between the study and control eyes. Multiple focal disruptions of the blood vessels by fat vacuoles were found with electron microscopic study. ERG improved at 12 and 48 h, and the BRB appeared to be recovered on FA and electron microscopic studies after 48 h. Conclusion: An experimental embolism with triolein emulsion disrupted the blood retinal barrier. Delayed maximal change was observed, and it could be implicated in the latent interval of clinical fat embolism syndrome.

Intramedullary Canal Pressure Distribution: An Experimental Parametric Study

Intramedullary instrument/device insertion during total joint replacement can generate high intramedullary pressures, with potential for clinical fat embolism syndrome. We evaluated effects of process parameters on intramedullary pressure generated when hammering an implant into a simulated femur analogue. Lower implant insertion speed, lower hammering force, a rubber- compared with steel-tipped hammer and a larger synthetic bone-to-implant radial gap reduced intramedullary pressure generated. Number of hammer strikes required to insert an implant increased with increasing marrow viscosity, whereas intramedullary pressure decreased with increasing viscosity. Significant intramedullary pressure reduction is obtained by applying more strikes of lower peak force using a rubber hammer tip, as opposed to fewer larger strikes. Caution should be exercised when instrumenting the distal femur, where viscosity is low and very high intramedullary pressures can be generated.

Therapeutic aspects of fat embolism syndrome

Signs and symptoms of clinical fat embolism syndrome (FES) usually begin within 24-48 hours after trauma. The classic triad involves pulmonary changes, cerebral dysfunction, and petechial rash. Clinical diagnosis is key because laboratory and radiographic diagnosis is not specific and can be inconsistent. The duration of FES is difficult to predict because it is often subclinical or may be overshadowed by other illnesses or injuries. Medical care is prophylactic or supportive, including early fixation and general ICU management to ensure adequate oxygenation and ventilation, hemodynamic stability, prophylaxis of deep venous thrombosis, stress-related gastrointestinal bleeding, and nutrition. Studies support early fracture fixation as a method to reduce recurrent fat embolism and FES. The main therapeutic interventions once FES has been clinically diagnosed are directed towards support of pulmonary and neurological manifestations and management of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS).

FAT EMBOLISM SYNDROME

Since it was initially described, fat embolism syndrome (FES) has remained one of the least clearly understood complications of trauma. This article is a review of the classic and current literature on FES with regard to its causes, pathophysiology, clinical presentation, diagnosis, and treatment. FES is associated with many traumatic and nontraumatic conditions, but is most commonly associated with fractures of long bones of the lower extremity. The pathophysiology is thought to be a cascade of events which can lead to adult respiratory distress syndrome (ARDS). Signs and symptoms of clinical FES usually begin within 24 to 48 hours after trauma. The classic triad involves pulmonary changes, cerebral dysfunction, and petechial rash. Clinical diagnosis is key because laboratory and roentgenographic diagnosis is not specific. Treatment consists of careful initial handling, early stabilization of fractures, careful volume replacement, analgesia, respiratory support, and perhaps steroids. The vast majority of patients today survive FES without sequelae.

Clinically Inapparent Hypoxemia After Skeletal Injury The Use of the Pulse Oximeter as a Screening Method

The efficacy of the pulse oximeter was evaluated in lieu of multiple arterial blood gas (ABG) determinations as a screening method for the early diagnosis of hypoxemia and clinical fat embolism syndrome. A prospective analysis was performed on 43 patients with long bone and pelvic fractures without any associated chest wall, head, or intraabdominal trauma. A standard pulse oximetry reading was obtained initially within 12 hours of injury and at 24-hour intervals thereafter until the patient had been observed for 72 hours. Fifteen patients were hypoxemic with an oxygen-hemoglobin (O2-Hb) saturation less than or equal to 94%. All hypoxemic patients were evaluated by ABG measurements that demonstrated the expected correlation with the pulse oximetry readings. These patients were subsequently managed with an intensive pulmonary care regimen. Hypoxemia resolved in all patients within 48 hours of the initiation of treatment. The pulse oximeter is an efficient and reliable screening device to identify patients with clinically unrecognized hypoxemia.

Fat release after femur nailing in the dog.

Internal fixation of fractures in the first few hours following injury has important advantages. It can diminish continued blood loss, improve patient mobility, and may help avoid pulmonary and cardiovascular complications of multiple trauma. Fear of increased risk of fat embolism has limited its use. We studied the release of fat during intramedullary reaming and nailing of the femur in dogs. Comparing fat release from an intact and a fractured femur in each dog, significantly more triglyceride was released from the intact bone than from the fractured femur. Thus, reaming a fractured bone produces minimal embolization. The presence of a fracture may decompress the pressure in the medullary canal, minimizing the release of fat into the circulation during acute internal fixation. This could help to explain the low incidence of clinical fat embolism syndrome associated with immediate intramedullary nailing of the femur.

Fat embolism in patients with multiple injuries.

The diagnostic criteria of clinical fat embolism syndrome are most important. Petechial rush, positive chest X-ray films, low arterial oxygen content, and cerebral involvement are major features. Three different grades of fat embolism can be distinguished. The development of the first grade cannot be prevented. By early internal fixation of long-bone fractures in patients with multiple injuries it may be possible in most cases to prevent the development of the third grade, the severe clinical fat embolism syndrome. Thus specific treatment because of fat embolism was indicated in only three cases in this series of 211 patients with broken long bones and multiple injuries.

Corticosteroids in patients with a high risk of fat embolism syndrome

The effects of methylprednisolone on the clinical fat embolism syndrome were studied in a series of 60 patients who had at least two fractures of the pelvis, femur and tibia and who did not have any other important injuries. This series was dichotomized at random, and 29 patients were given 10 milligrams per kilogram of methylprednisolone three times, once upon admission and, then, at eight and 16 hours post-traumatically. Thirty-one patients served as controls. Fat embolism syndrome was defined as a combination of hypoxemia, bilateral "snow storm" infiltrations of the lungs, petechial rash, mental disturbances, pyrexia, anemia and thrombocytopenia. Varying degrees of the syndrome were observed in two patients given methylprednisolone and in 15 patients in the control group. Methylprednisolone reduced all individual signs. There were no fatalities in this series of fracturers. No complications were observed from the use of methylprednisolone. Methylprednisolone in an early pharmacologic dosage is effective in fulminant instances of fat embolism that occur in spite of adequate respiratory care and the proper treatment of fractures.

The Use of Methylprednisolone and Hypertonic Glucose in the Prophylaxis of Fat Embolism Syndrome

In a prospective randomized trial of prophylactic therapy in fat embolism syndrome (FES) 64 patients with femoral and/or tibial shaft fractures uncomplicated by other significant injuries were treated with hypertonic glucose (A), methylprednisolone (B), and placebo (C). Clinical findings and several laboratory parameters were used to establish the diagnosis. Two of the 23 patients in the placebo group (C), 3 of the 21 patients in the hypertonic dextrose (A) group and none of the 20 patients in the methylprednisolone (B) group developed clinical fat embolism syndrome. All patients with fat embolism syndrome were hypoxemic (pO2 less than 65 mm Hg) and exhibited central nervous system symptoms. Four out of 5 were hypocalcemic and 3 patients had thrombocytopenia. There was a high incidence of subclinical hypoxemia or subclinical fat embolism syndrome (29% in A Group, 15% in B Group and 39% in C Group). A comparison between groups of the mean pO2 for each patient demonstrated a statistically significant difference between the methylprednisolone group and the control group (p less than 0.025) as was the comparison of proportions of pO2 less than 70 mm Hg (methylprednisolone versus control p less than 0.01, glucose versus control p less than 0.03). Methylprednisolone given prophylactically may reduce the incidence of fat embolism syndrome and can reduce the degree of hypoxemia associated with long bone fractures of the lower extremmity.

Early diagnosis of the fat embolism syndrome.

One hundred consecutive cases of trauma with associated fractures of the lower limb long bones were studied for the subsequent development of the fat embolism syndrome (FES). This is to be differentiated from the intravascular fat embolism which often occurs without clinical FES becoming manifest. Seventeen of the patients developed the clinical picture, with a further 16 patients being considered to have had the syndrome subclinically. Clinical and biochemical features were studied to determine pointers to the early diagnosis and patient "at risk" of developing FES. Young males under the age of 30 with significant hypoxemia occurring early in the course of the disease were considered the most likely candidates "at risk" for developing FES. These results favor the concept that FES is essentially a form of respiratory insufficiency syndrome similar to that which occurs following trauma in other situations, e.g., shock lung.