Prevention of fat embolism syndrome

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.

A Case of Fulminant Fat Embolism Syndrome With Very Early Onset After Femoral Neck and Sacral Fractures

Fulminant fat embolism syndrome (FES) occurring within 1 h after trauma is extremely rare. We report a case of fulminant FES that developed hyperacute nature after a traumatic injury. A 66-year-old woman was injured when she fell approximately 1.5 m down the stairs. She was rushed to our hospital. One minute after arrival, which was 49 min after the injury, her consciousness and respiratory status deteriorated. Thoracoabdominal and pelvic computed tomography revealed preexisting interstitial pneumonia, a left femoral neck fracture, and a left sacral fracture. Head magnetic resonance imaging (diffusion-weighted imaging) showed diffuse high-signal areas and susceptibility-weighted imaging showed diffuse small perivascular of perivascular hemorrhages. She was diagnosed with fulminant FES. After conservative treatment, she was transferred to a rehabilitation hospital with a Glasgow Coma Scale (GCS) of 8 and a modified Rankin Scale of 5 on Day 45. The possibility of fulminant FES should be considered a cause of early impaired consciousness after a fracture.

Dyspnea after endomedullary nailing: Fat embolism

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

Fat embolism syndrome in a patient that sustained a femoral neck fracture: A case report

Background

We present a case of a patient with a femoral neck fracture that shows neurological impairment and respiratory distress 1 day after trauma, caused by the Fat Embolism Syndrome with the presence of Cerebral Fat Embolisms.

Case summary

A 75 year old female remained unresponsive after a hemi arthroplasty was performed because of a 1 day old femoral neck fracture. She rapidly developed respiratory insufficiency and an obstructive shock with right ventricle dilatation on transthoracic echocardiography. The diffusion-weighted MRI brain images showed the "Starfield" pattern, a radiologic phenomenon typical for FES. During 3 weeks of ICU admission the neurologic state slowly ameliorated.

Conclusion

The rare FES is a clinical diagnosis with mainly respiratory, neurologic and dermatologic symptoms in the setting of a trauma patient. Fat embolisms are able to reach the brain without the presence of a patent foramen ovale to cause neurological symptoms. Diagnosing FES remains challenging but the distinctive "Starfield" pattern on MRI scans is promising.

Diagnostic significance of fat globules in blood in fulminant-type fat embolism syndrome

Fat globule detection in the blood in fat embolism syndrome (FES) diagnosis remains controversial. This case illustrates two life-threatening, possibly FES-related, episodes with dramatic increases in blood fat globule level. Future studies should aim at evaluating the significance of the quantitative changes in blood fat levels in diagnosing FES.

Fat Embolism Syndrome - A Qualitative Review of its Incidence, Presentation, Pathogenesis and Management

Fat Embolism Syndrome (FES) is a poorly defined clinical phenomenon which has been attributed to fat emboli entering the circulation. It is common, and its clinical presentation may be either subtle or dramatic and life threatening. This is a review of the history, causes, pathophysiology, presentation, diagnosis and management of FES. FES mostly occurs secondary to orthopaedic trauma; it is less frequently associated with other traumatic and atraumatic conditions. There is no single test for diagnosing FES. Diagnosis of FES is often missed due to its subclinical presentation and/or confounding injuries in more severely injured patients. FES is most frequently diagnosed using the Gurd and Wilson criteria, like its rivals it is not clinically validated. Although FES is a multi-system condition, its effects in the lung, brain, cardiovascular system and skin cause most morbidity. FES is mostly a self-limiting condition and treatment is supportive in nature. Many treatments have been trialled, most notably corticosteroids and heparin, however no validated treatment has been established.

Rapamycin alleviated pulmonary injury induced by fat embolism syndrome in rats

Fat embolism syndrome (FES) is a serious complication after trauma, surgery and fat emulsion input and can lead to serious pulmonary injury. Autophagy controls the cell survival and homeostasis by removing the mis-folded proteins and damaged organelles as well as intracellular pathogens through a lysosomal degradation pathway. Increasing research documented that autophagy was wildly involved in variety of human diseases and had huge therapeutic potential. However, the role and mechanism of autophagy in FES remains largely unknown. The rat model of FES was established by tail vein injection with fat and was assessed by Wet-to-Dry (W/D) ratio analysis, hematoxylin-eosin (HE) analysis, staining Oil red staining analysis and qPCR analysis. Western blots were employed to detect the expression of autophagy markers. The changes of pulmonary injury were observed after premedication of rapamycin (an autophagy activator). The alveolar structural damage, red free fat substances in the blood vessels of lung, increased the lung ratio, and the up-regulated MPO expression and activity were showed in the FES models. The expressions of autophagy markers were decreased and meanwhile, apoptosis markers were increased in the FES model. Rapamycin restored the expression of autophagy markers and inhibited the apoptosis and further, resulting in the improvement of the pulmonary injury. Thus, our study demonstrated that autophagy was inhibited and apoptosis was promoted in FES and further Rapamycin alleviated the pulmonary damage in FES via restoring the autophagy and inhibiting the apoptosis.

The fat embolism syndrome as a cause of paraplegia

The fat embolism syndrome is a well-known complication in trauma patients. We describe a rare case of traumatic fat embolism that leads to paraplegia. A 19-year-old male motorcycle accident victim was presented to our hospital. After stabilization and trauma survey, he was diagnosed with bilateral femur fractures, a spleen laceration and a tear in the inferior vena cava, for which damage control surgery was performed. Post-operatively, the patient became paraplegic and developed a fluctuating consciousness, respiratory distress and petechiae. Fat embolism syndrome was considered as the most plausible cause of the paraplegia. The fat embolism syndrome is seen in approximately 1% of trauma patients, mostly those with bilateral fractures of the femur. Prevention of the syndrome depends on early stabilization of fractures. However, even with optimal care, this syndrome can still occur and may have dramatic consequences, as we demonstrate in this case.

Fulminant Cerebral Fat Embolism: Case Description and Review of the Literature

The release of fat and bone marrow fragments is a common occurrence following traumatic and nontraumatic events. In most cases, they go symptomless or cause only minor disturbances, but occasionally they can determine a multiorgan dysfunction whose severity ranges from mild to fatal. The authors describe the case of a patient who became deeply comatose and ultimately died after a traffic accident in which he suffered the exposed right femoral and tibial fracture in the absence of other injuries. He underwent the external fixation of the fractured bones 2 hours after the admission under general anesthesia. Three hours later, he failed to awake at the suspension of the anesthetic agents and became anisocoric; a CT scan demonstrated a diffuse cerebral edema with the herniation of the cerebellar tonsils; these abnormalities were unresponsive to the treatment and the brain death was one day later. The causes, the mechanisms, the symptoms, the prevention, and the treatment of the syndrome are reviewed and discussed.

Fat embolism syndrome in femoral shaft fractures: does the initial treatment make a difference?

Objective

To identify the risk factors correlated with the initial treatment performed.

Methods

This is a retrospective study involving a total of 272 patients diagnosed with femoral shaft fractures. Of the patients, 14% were kept at rest until the surgical treatment, 52% underwent external fixation, 10% received immediate definitive treatment, and 23% remained in skeletal traction (23%) until definitive treatment.

Results

There were six cases of fat embolism syndrome (FES), which showed that polytrauma is the main risk factor for its development and that initial therapy was not important.

Conclusion

Polytrauma patients have a greater chance of developing FES and there was no influence from the initial treatment.

A Simple and Easy Intramedullary Lavage Method to Prevent Embolism During and After Reamed Long Bone Nailing

Reaming of the long bones is widely practiced because it allows for improved healing and early mobilization in patients needing surgical debridement of bone tissue. The insertion of reamed intramedullary nails can cause complications such as bone necrosis, cortical blood supply damage, and fat or bone marrow embolism. We describe a novel way to limit the amount of material in the canal before nail insertion to limit the chances of embolism.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Surgical Stabilization of Femur Fractures in Post-Traumatic Hypoxemic Patients: When and Why?

Background:

Post-traumatic hypoxemia can deteriorate during operative manipulations.

Objectives:

In the present study, criteria-based approach was applied to determine optimum conditions for femur surgery. The aim of this study was to optimize perioperative management of post-traumatic hypoxemia.

Patients and Methods:

In this prospective observational study, post-traumatic adults with PaO₂ < 70 mmHg in room air were enrolled. Physiological parameters, O₂ saturation (SO₂), arterial blood gas (ABG) analysis, Schonfeld fat embolism index score (SS), and Murray’s lung injury scores (LIS) were assessed. The management protocol was femur surgery when patient was hemodynamically stable with LIS < 2.5 and PaO₂/FiO₂ > 200 mmHg (FiO₂ < 0.5, PEEP < 8 cm H₂O).

Results:

A total of 31 adults (26 males and 5 females) with LIS of 0.1 to 2.5 (26 patients) and > 2.5 (five patients) at admission were recruited. Sixteen patients were admitted within 24 hours and 15 between 24 and 90 hours after injury. Thirteen patients were operated within 24 hours. Post-operative LIS was improved. No adverse sequels or mortality were seen.

Conclusions:

Appropriate surgical stabilization can be safely performed during established post-traumatic hypoxemia using a multidisciplinary approach, continuous monitoring, and serial investigations to diagnose fulminant pathology and associated injuries.

Lateral drill holes decrease strength of the femur: an observational study using finite element and experimental analyses

Background

Internal fixation of femoral fractures requires drilling holes through the cortical bone of the shaft of the femur. Intramedullary suction reduces the fat emboli produced by reaming and nailing femoral fractures but requires four suction portals to be drilled into the femoral shaft. This work investigated the effect of these additional holes on the strength of the femur.

Methods

Finite element analysis (FEA) was used to calculate compression, tension and load limits which were then compared to the results from mechanical testing. Models of intact femora and fractured femora internally fixed with intramedullary nailing were generated. In addition, four suction portals, lateral, anterior and posterior, were modelled. Stresses were used to calculate safety factors and predict fatigue. Physical testing on synthetic femora was carried out on a universal mechanical testing machine.

Results

The FEA model for stresses generated during walking showed tensile stresses in the lateral femur and compression stresses in the medial femur with a maximum sheer stress through the neck of the femur. The lateral suction portals produced tensile stresses up to over 300% greater than in the femur without suction portals. The anterior and posterior portals did not significantly increase stresses. The lateral suction portals had a safety factor of 0.7, while the anterior and posterior posts had safety factors of 2.4 times walking loads. Synthetic bone subjected to cyclical loading and load to failure showed similar results. On mechanical testing, all constructs failed at the neck of the femur.

Conclusions

The anterior suction portals produced minimal increases in stress to loading so are the preferred site should a femur require such drill holes for suction or internal fixation.

Hyperacute cerebral fat embolism in a patient with femoral shaft fracture

Fat embolism syndrome is a potentially fatal complication and occurs most commonly after long bone fracture. In patients who sustained severe trauma, both cerebral fat embolism(CFE) and diffuse axonal injury (DAI) could be the cause of altered consciousness in the absence of marked intracranial lesions in cranial computed tomography. However, distinguishing CFE and DAI can be difficult clinically. Generally, DAI develops immediately after the insult, whereas CFE occurs 48 to 72 hours after the trauma and even after internal fixation for the fractures. Fat embolism syndrome develops within an average of 48.5 hours after long bone fracture [1] but has never been reported to occur in less than 2 hours. Here, we present a patient who developed hyperacute CFE and eventually had poor neurological outcome, in contrast to previous reports stating that CFE usually has a long latent period and favorable outcomes.

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

Fat embolism syndrome (FES) is an ill-defined clinical entity that arises from the systemic manifestations of fat emboli within the microcirculation. Embolized fat within capillary beds cause direct tissue damage as well as induce a systemic inflammatory response resulting in pulmonary, cutaneous, neurological, and retinal symptoms. This is most commonly seen following orthopedic trauma; however, patients with many clinical conditions including bone marrow transplant, pancreatitis, and following liposuction. No definitive diagnostic criteria or tests have been developed, making the diagnosis of FES difficult. While treatment for FES is largely supportive, early operative fixation of long bone fractures decreases the likelihood of a patient developing FES.

Clinical utility of intra-operative 6% hydroxyethyl starch (130 / 0.4) supplementation in hypoxemic femur injury patients: a preliminary report of twenty cases

Abstract

Posttraumatic intravasation of fat and debris can lead to a cascade of events. Hydroxyethyl starches (HES) markedly suppress neutrophil influx by decreasing pulmonary capillary permeability and facilitating tissue oxygenation by improving microcirculation. It was hypothesized that in hypoxemic femur injury patients undergoing operative stabilization, HES administration will prevent the deterioration of respiratory variables and facilitates recovery. This prospective, double-blind, randomized preliminary study, enrolled twenty posttraumatic hypoxemic patients (room air PaO2 < 70 mmHg, Schonfeld fat embolism index score (SS) > 5) scheduled for femur fracture stabilization under general anesthesia. Patients were allocated to receive either; 6% HES 130/0.42, 15 mL/kg or 0.9% normal saline (NS) to maintain their central venous pressure (CVP) 12 + 2 mm Hg. Blood was transfused according to the maximum allowable blood loss and by serial hematocrit estimations. Perioperative Glasgow Coma Scale (GCS), physiological variables, arterial oxygen saturation (SpO2), arterial blood gas (ABG), SS and P/F ratios were recorded until recovery. The partial pressure of oxygen in arterial blood / fraction of inspired oxygen ratio (PaO2/FiO2) improved from a preoperative value of 273.33 ± 13.05 to 435.70 in the 6% Hydroxyethyl starch group (HES) and from 275.24 ± 15.34 to 302.25 ± 70.35 in the NS group over a period of six days (P values =0.970, 0.791, 0.345, 0.226, 0.855, 0.083, 0.221). Time taken to achieve a P/F ratio > 300 and for persistent reduction of Murray’s lung injury score (LIS) were comparable (P = 0.755 and 0.348, respectively). The number of ventilator, intensive care unit (ICU) and hospital stay days, did not differ (P value = 0.234, 1.00, 0. 301, respectively). There were no adverse sequelae or mortalities. A trend showing relatively fast improvement in the P/F ratio and an early reduction in LIS values was observed in hypoxemic, femur injury patients receiving intraoperative colloid supplementation.

[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.

Role of corticosteroid as a prophylactic measure in fat embolism syndrome: a literature review

Despite a number of studies on steroid therapy as a prophylactic measure in fat embolism syndrome (FES), there is no universal agreement about its role in this critical situation. The present article attempts to search the available literature, and provides a more lucid picture to the readers on this issue. Seven articles (total 483 patients) were reviewed and analyzed. Total of 223 patients received steroid (methyl prednisolone sodium succinate), while the remaining 260 patients formed the control population. Among these subjects, 9 patients in steroid-receiving group and 60 patients in the control group developed FES (P < 0.05). The lack of uniformities in these studies, variable dose and single-center trial are the principal limitations and confuses the surgeons to have definite conclusion. Large-scale, more uniformly designed, multi-centered, randomized, prospective trials are needed to determine the correct situations and dosage in which steroids provide the maximum benefit (with the least possible risk).

Effects of phorbol myristate acetate and sivelestat on the lung injury caused by fat embolism in isolated lungs

Background

Fat embolism syndrome (FES) associated with acute lung injury (ALI) is a clinical condition following long bone fracture. We have reported 14 victims due to ALI with FES. Our laboratory has developed an animal model that produced fat emboli (FE). The major purpose of this study was to test whether neutrophil activation with phorbol myristate acetate (PMA) and inhibition with sivelestat (SVT) exert protection on the lung.

Methods

The lungs of Sprague-Dawley rats were isolated and perfused. FE was produced by addition of corn oil micelles into the lung perfusate. PMA and SVT were given simultaneously with FE. Parameters such as lung weight/body weight ratio, LW gain, exhaled nitric oxide (NO), protein concentration in bronchoalveolar lavage relating to ALI were measured. The neutrophil elastase (NE), myeloperoxidase, malondialdehyde and phopholipase A₂ activity were determined. We also measured the nitrate/nitrite, methyl guanidine (MG), and cytokines. Pulmonary arterial pressure and microvascular permeability were assessed. Lung pathology was examined and scored. The inducible and endothelial NO synthase (iNOS and eNOS) were detected.

Results

FE caused ALI and increased biochemical factors. The challenge also resulted in pulmonary hypertension and increased microvascular permeability. The NE appeared to be the first to reach its peak at 1 hr, followed by other factors. Coadministration with PMA exacerbated the FE-induced changes, while SVT attenuated the effects of FE.

Conclusions

The FE-induced lung changes were enhanced by PMA, while SVT had the opposite effect. Sivelestat, a neutrophil inhibitor may be a therapeutic choice for patients with acute respiratory distress syndrome (ARDS) following fat embolism.

Fat embolism syndrome in long bone fracture--clinical experience in a tertiary referral center in Taiwan

BACKGROUND

Fat embolism syndrome (FES) is a potentially fatal complication of long bone fractures. There have been no reports of FES in long bone fractures in this decade in Taiwan. The purpose of this study was to review the FES experiences in a tertiary referral center between January 1997 and February 2008.

METHODS

Between January 1997 and February 2008, 13 patients with long bone fractures with documented FES in our institution were reviewed. FES was diagnosed clinically by at least 2 major criteria or 1 major with at least 4 minor signs of Gurd's criteria.

RESULTS

The incidences of FES, less than those reported in the literature, were 0.15% in fracture of the tibia, 0.78% in fracture of the femur and 2.4% in multiple fractures. The mortality rate of FES, similar to other available results, was about 7.7%. All cases were less than 35 years old, except for 1 70-year-old male. Fat embolism occurred within an average of 48.5 hours after long bone fracture. Eleven presented with sudden drop in hemoglobin level, dropping 4.2 g/dL on average. Nine presented with thrombocytopenia, and 10 presented with sudden drop in platelet count, dropping 140,000/dL on average. Two had cerebral sequelae without recovery at the last 48-month follow-up.

CONCLUSION

This 12-year interval retrospective study revealed modern epidemiologic results for FES in long bone fracture. Compared with the available literature in the recent decade, the incidence of FES in long bone fracture in our institution is less and the mortality rate is similar.

Diagnosis of fatal pulmonary fat embolism with minimally invasive virtual autopsy and post-mortem biopsy

We report a case of a 78-year-old female with a proximal femur fracture caused by an accidental fall who died suddenly 1h after orthopaedic prosthesis insertion. Post-mortem computed tomography (CT) scan and histological examination of samples obtained with post-mortem percutaneous needle biopsies of both lungs were performed. Analysis of the medical history and the clinical scenario immediately before death, imaging data, and biopsy histology established the cause of death without proceeding to traditional autopsy. It was determined to be acute right ventricular failure caused by massive pulmonary fat embolism. Although further research in post-mortem imaging and post-mortem tissue sampling by needle biopsies is necessary, we conclude that the use of CT techniques and percutaneous biopsy, as additional tools, can offer a viable alternative to traditional autopsy in selected cases and may increase the number of minimally invasive forensic examinations performed in the future.

A Lethal Case of Fat Embolism Syndrome in a Nine-Year-Old Child: Options for Prevention

We report a lethal case of fat embolism syndrome in a nine-year-old child after a direct blunt trauma leading to a pelvic fracture. On the second day, signs of bowel perforation and septic shock led to an acute aggravation of the pulmonary symptoms, cardiac arrest and death. Fat embolism is seldom thought to occur in pediatric trauma patients; however, this case illustrates it can lead to disastrous sequela. Since there is no specific treatment for it, prevention by early fracture stabilization is the only option.

Histopathological and biochemical changes following fat embolism with administration of corn oil micelles

Several experimental models have been used to produce intravascular fat embolism. We have developed a simple technique to induce fat embolism using corn oil emulsified with distilled water to form fatty micelles. Fat embolism was produced by intravenous administration of these fatty micelles in anaesthetised rats, causing alveolar oedema, haemorrhage and increased lung weight.

Histopathological examination revealed fatty droplets and fibrin thrombi in the lung, kidney and brain. The arteriolar lumen was filled with fatty deposits. Following fat embolism, hypoxia and hypercapnia occurred. The plasma phospholipase A2, nitrate/nitrite, methylguidanidine and proinflammatory cytokines were significantly increased. Mass spectrometry showed that the main ingredient of corn oil was oleic acid.

This simple technique may be applied as a new animal model for the investigation of the mechanisms involved in the fat embolism syndrome.

Clinical and pathological features of fat embolism with acute respiratory distress syndrome

FES (fat embolism syndrome) is a clinical problem, and, although ARDS (acute respiratory distress syndrome) has been considered as a serious complication of FES, the pathogenesis of ARDS associated with FES remains unclear. In the present study, we investigated the clinical manifestations, and biochemical and pathophysiological changes, in subjects associated with FES and ARDS, to elucidate the possible mechanisms involved in this disorder. A total of eight patients with FES were studied, and arterial blood pH, PaO(2) (arterial partial pressure of O(2)), PaCO(2) (arterial partial pressure of CO(2)), biochemical and pathophysiological data were obtained. These subjects suffered from crash injuries and developed FES associated with ARDS, and each died within 2 h after admission. In the subjects, chest radiography revealed that the lungs were clear on admission, and pulmonary infiltration was observed within 2 h of admission. Arterial blood pH and PaO(2) declined, whereas PaCO(2) increased. Plasma PLA(2) (phospholipase A(2)), nitrate/nitrite, methylguanidine, TNF-alpha (tumour necrosis factor-alpha), IL-1beta (interleukin-1beta) and IL-10 (interleukin-10) were significantly elevated. Pathological examinations revealed alveolar oedema and haemorrhage with multiple fat droplet depositions and fibrin thrombi. Fat droplets were also found in the arterioles and/or capillaries in the lung, kidney and brain. Immunohistochemical staining identified iNOS (inducible nitric oxide synthase) in alveolar macrophages. In conclusion, our clinical analysis suggests that PLA(2), NO, free radicals and pro-inflammatory cytokines are involved in the pathogenesis of ARDS associated with FES. The major source of NO is the alveolar macrophages.

Care of the orthopaedic trauma patient

The perianesthesia nursing care of the orthopaedic trauma patient focuses on injuries of the musculoskeletal system and the associated muscles, ligaments, tendons, and joints. Multitrauma patients often sustain more than one musculoskeletal injury at the time of the traumatic event. Early stabilization, astute nursing assessments, and interventions are imperative to the patient's functional outcome and rehabilitation. Knowing the mechanism of injury is essential to understanding and caring for musculoskeletal trauma injuries. Because patients with traumatic orthopaedic injuries are at a higher risk for wound infections, it is important for perianesthesia nurses to initiate careful infection control practices. Recognizing significant orthopaedic trauma complications that include compartment syndrome, fat embolism syndrome, and hypovolemic shock is vital for saving the life or limb of the patient.