Post-traumatic cerebral fat embolism syndrome with a favourable outcome: a case report

A hypoxic young lady in an acute confusional state

Patients presenting with respiratory and neurological symptoms after a breast filler injection should alert the clinician to this potential diagnosis https://bit.ly/3OodFQA.

Femoral Nailing in a Porcine Model Causes Bone Marrow Emboli in the Lungs and Systemic Emboli in the Heart and Brain

Background

Shaft fractures of the femur are commonly treated with intramedullary nailing, which can release bone marrow emboli into the bloodstream. Emboli can travel to the lungs, impairing gas exchange and causing inflammation. Occasionally, emboli traverse from the pulmonary to the systemic circulation, hindering perfusion and resulting in injuries such as heart and brain infarctions, known as fat embolism syndrome. We studied the extent of systemic bone marrow embolization in a pig model.

Methods

Twelve anesthetized pigs underwent bilateral intramedullary nailing of the femur, while 3 animals served as sham controls. Monitoring included transesophageal echocardiography (TEE), pulse oximetry, electrocardiography, arterial blood pressure measurement, and blood gas and troponin-I analysis. After surgery, animals were monitored for 240 minutes before euthanasia. Post mortem, the heart, lungs, and brain were biopsied.

Results

Bone marrow emboli were found in the heart and lungs of all 12 of the pigs that underwent intramedullary nailing and in the brains of 11 of them. No emboli were found in the sham group. The pigs subjected to intramedullary nailing exhibited significant hypoxia (PaO2/FiO2 ratio, 410 mm Hg [95% confidence interval (CI), 310 to 510) compared with the sham group (594 mm Hg [95% CI, 528 to 660]). The nailing group exhibited ST-segment alterations consistent with myocardial ischemia and a significant increase in the troponin-I level compared with the sham group (1,580 ng/L [95% CI, 0 to 3,456] versus 241 ng/L [95% CI, 0 to 625] at the 240-minute time point; p = 0.005). TEE detected emboli in the right ventricular outflow tract, but not systemically, in the nailing group.

Conclusions

Bilateral intramedullary nailing caused bone marrow emboli in the lungs and systemic emboli in the heart and brain in this pig model. The observed clinical manifestations were consistent with coronary and pulmonary emboli. TEE detected pulmonary but not systemic embolization.

Clinical Relevance

Femoral intramedullary nailing in humans is likely to result in embolization as described in our pig model. Focused monitoring is necessary for detection of fat embolism syndrome. Absence of visual emboli in the left ventricle on TEE does not exclude the occurrence of systemic bone marrow emboli.

Do you know the diagnostic importance of susceptibility-weighted imaging on MRI for patients with cerebral fat embolism?

Key Clinical Message

If you suspect cerebral fat embolism (CFE) of the diagnosis for the patients who present with impaired consciousness and hypoxia following a fracture, susceptibility-weighted imaging should be included of head MRI imaging.

Abstract

We report a case of cerebral fat embolism (CFE) that could be identified only by susceptibility-weighted imaging (SWI). Collection and analysis of previous case reports of CFE revealed utilization of SWI in less than one third of suspected cases, despite its known diagnostic ability for CFE.

Occurrence of Numerous Cerebral White Matter Hyperintensities in Trauma Patients With Cerebral Fat Embolism: A Systematic Review and Report of Two Cases

There has been little effort to identify an overall occurrence of numerous cerebral white matter hyperintensities (NCWMH) on relevant brain magnetic resonance imaging (MRI) sequences in postinjury cerebral fat embolism syndrome (CFES) patients. Also, quantification of pre-CFES cognitive status, degree of neurologic deterioration, and presence of a skeletal fracture with CFES is nominal. The authors performed a PubMed search and identified 24 relevant manuscripts. Two case reports from the authors' institution were also used. The presence of NCWMH was assessed by reviewing T2-weighted image (T2WI), diffusion-weighted image (DWI), fluid-attenuated inversion recovery (FLAIR) figures and captions, and by evaluating manuscript descriptions. When pre-CFES cognitive status was described, it was categorized as Glasgow Coma Scale (GCS) score = 14-15 (yes or no). When the degree of neurologic deterioration was noted with CFES, it was classified as coma or GCS ≤ 8 (yes or no). When skeletal fractures were itemized, they were categorized as yes or no. The total number of CFES patients was 133 (literature search was 131 and two author-described case reports). Of the 131 patients with manuscript MRI figures or descriptive statements, 120 (91. 6%) had NCWMH. Of 63 patients with a delineation of the MRI sequence, NCWMH appeared on DWI in 24, on T2WI in 57, and on FLAIR in 10 patients. Pre-CFES cognitive status was GCS 14-15 in 93.5% (58/62) of the patients. The CFES neurologic deterioration was coma or GCS ≤ 8 in 52.5% (62/118) of the patients. A skeletal fracture was present in 99.0% (101/102) of the CFES patients. The presence of NCWMH in trauma patients with hospital-acquired neurologic deterioration and the presence of a skeletal fracture is consistent with CFES.

A Rare Case of Progressive Encephalopathy in a Sickle Cell Trait Patient: A Case Report

Fat embolism syndrome (FES) is one of the underdiagnosed and underrecognized complications that can happen in multiple medical and surgical conditions. FES can manifest in a broad spectrum of signs and symptoms and affect multiple organ systems in the human body. One of the most commonly involved is the central nervous system (CNS), mainly the brain, which can be involved in different ways, and the presenting symptoms can vary in type and severity. One of the most common causes of FES is trauma, mainly a long bone fracture or any orthopedic injury. However, one of the rare causes of FES is sickle cell disease (SCD) and thalassemia. Generalized and vague presenting symptoms, the rarity of FES, and the absence of well-defined diagnostic criteria make it a challenging diagnosis for healthcare practitioners. FES diagnosis is usually made after having a high index of suspicion in patients with underlying risk factors that can precipitate and contribute to the pathophysiology of FES. Moreover, the diagnosis is usually reached after excluding other more common and treatable conditions.

Devastating neurologic injury associated with fat embolism syndrome

ABSTRACT

The diagnosis of fat embolism syndrome (FES) may present with a constellation of symptoms and continues to be a diagnosis of exclusion. Fat embolism syndrome is a poorly understood syndrome, which is typically associated with orthopedic trauma, most commonly with long bone fractures. Understanding the presentation of FES is essential to provide timely and appropriate interventions and to ensure optimal patient outcomes. The following is a case report of FES in a 39-year-old man following a motor vehicle collision in which he sustained a comminuted fracture of the right femur. The patient was subsequently diagnosed with FES using Gurd criteria in conjunction with frequent assessment of the patient's clinical picture, as well as exclusion of other differential diagnoses. Nurse practitioners and other providers should understand the constellation of symptoms that may be associated with FES to improve prevention and ensure timely intervention.

Susceptibility-weighted imaging of cerebral fat embolism: A case report

RATIONALE

Cerebral fat embolism (CFE) is a rare but critical disease in a clinical setting. Considering that manifestations and CT findings of CFE tend to be atypical, this condition is very difficult to diagnose. The purpose of this article was to assess the value of susceptibility-weighted imaging (SWI) in the diagnosis of CFE.

PATIENT CONCERNS

Our patient was an 80-year-old woman who developed hypoxemia, quadriplegia, and progressive confusion after fracture of the right femoral neck and right superior ramus of pubis within 24 hours.

DIAGNOSIS

T2-weighted magnetic resonance imaging (T2 W MRI), fluid-attenuated inversion recovery sequences, and diffusion-weighted imaging showed numerous hyperintense foci in the subcortex and white matter of both cerebral hemispheres, some of which were confluent and SWI showed multiple symmetrical punctate microhemorrhages in both hemispheres. Base on the history and MRI findings, the patient was diagnosed with CFE.

INTERVENTIONS

The patient received anticoagulation and lipid-lowering therapy.

OUTCOMES

The patient regained consciousness, and her muscle strength in the limbs gradually recovered. One year after discharge, the patient could independently walk on her own.

LESSION

This case report shows the characteristics of CFE on SWI, which can help clinicians in diagnosing which can help clinicians in diagnosing CFE.