A fat embolism is an embolism that results from fat droplets in the bloodstream. As a result of the blockage of a vessel by the fat droplets, an acute pulmonary embolism usually develops.
What is fat embolism?
The term embolism refers to the complete or partial blockage of a blood vessel by various substances and materials. In fat embolism, fat droplets enter the vessels through the blood. These are either released tissue fats or precipitated plasma fats. Plasma fats are also called lipoproteins. Lipoproteins are aggregates of proteins and fats. They serve to transport water-insoluble fats and cholesterol. The shell and contents of lipoproteins are susceptible to oxidation and thus to vascular deposition. When fat droplets become dislodged, they enter the narrow capillaries through the blood system and become lodged. Most often, fat embolism ends up in the blood vessels of the lungs. A pulmonary embolism occurs, with symptoms such as shortness of breath and chest pain. If the embolus travels to the arterial blood system, the fat droplets can cause a heart attack, stroke or kidney infarction. In some cases, fat embolism occurs along with fat embolism syndrome.
Causes
Fat embolism usually occurs after bone fractures. Bone marrow is made up of fat, among other things. If the bone marrow was damaged during fracture, fat can leak from the reticulum cells of the bone marrow and thus enter the bloodstream. After fractures of long tubular bones, in intramedullary nailing, and in fractures of multiple rib bones, very small fat emboli are found in the lungs in nearly 90 percent of patients. Fat droplets also enter the lungs after blunt trauma to fatty tissue or in fatty liver. It can take up to four days for the small fat molecules to reach the pulmonary vessels. Fat embolism can also be the result of a mechanical body fat reduction procedure called liposuction. Burns, rhabdomyolysis, bone marrow transplantation, and bone marrow aspiration can also cause fat embolism. Several diseases are also associated with fat embolism in clusters. These include acute pancreatitis, obesity, sickle cell disease, diabetes mellitus, viral hepatitis, muscular dystrophy, myocardial infarction, and systemic lupus erythematosus. Exogenous risk factors include tube feeding, propofol infusions, high-dose steroids, performance of lymphography, and high-dose chemotherapy.
Symptoms, complaints, and signs
Symptoms of fat embolism are often uncharacteristic. Affected patients complain of shortness of breath. Breathing is accelerated. The heart races and patients have chest pain. These may also radiate to the shoulder, back, or abdomen. The pain is accompanied by anxiety and restlessness. Patients may have to cough. If vessels burst in the lungs due to increased pressure, the sputum may be mixed with blood. Patients sweat profusely and complain of dizziness. If necessary, they faint. In some cases, cardiac arrhythmias also occur. If large blood vessels are affected by the fat embolism or if a large part of the lung is no longer supplied with blood, there is a risk of circulatory collapse with shock. Many of the patients with fat embolism exhibit slowed blood flow and increased blood viscosity. Vascular damage from the fat droplets leads to activation of blood clotting. The activated platelets release serotonin. This increases the permeability of the small blood vessels. Fluid leaks into the tissues, so shock can occur within a few hours. Before a large or multiple fat droplets block the pulmonary vessels, smaller emboli may occur. These manifest as mild chest pain, coughing or dizziness. However, small fat emboli can still be broken down by the body, so that the symptoms disappear after a short time. In the context of fat embolism, a fat embolism syndrome may develop. It is characterized by the triad of petechiae, neurologic symptoms, and respiratory symptoms and occurs 12 to 36 hours after trauma with fat embolism.
Diagnosis
The findings of fat embolism are often nonspecific. In some cases, major criteria such as dyspnea, rapid breathing, or chest pain are completely absent, making fat embolism often a diagnosis of exclusion.Blood and urine analyses may contain fat droplets and thus indicate fat embolism. Whether fat-containing phagocytes in bronchiolo-alveolar lavage are really always an indication of fat embolism of the lung is still under discussion. It is possible that a chest x-ray may provide further evidence of fat embolism. In the case of a pronounced embolism, patchy infiltrates are seen here in the upper fields of the lung. Arterial blood gas analysis can also provide clues. Hypoxia is often one of the early symptoms of fat embolism. Thrombocytopenia can be detected in one-third of patients. In two thirds unexplained anemia is described. Since both thrombocytopenia and anemia are nonspecific and the mechanism is still unclear, they can also be considered rather uncertain indications. Biochemical tests are also not sufficiently specific. For example, although serum lipase and phospholipase are elevated in lung injury from fat embolism, they are also elevated in trauma patients without fat embolism.
Complications
Serious complications can occur with fat embolism. These include pulmonary embolism, which in the worst case can lead to death. Since pulmonary embolism occurs primarily acutely, a rapid rescue by an emergency physician is necessary in this case so that the patient survives. In most cases, the affected person experiences shortness of breath. When breathing, there is pain in the chest, and the heart also beats faster. Patients often suffer from panic attacks and severe dizziness. The pain in the lungs and heart leads to inner restlessness and fear of a heart attack. The rapid palpitations also cause sweating, and some sufferers then lose consciousness and faint. Due to the fat embolism, the patient is severely restricted in his or her everyday life. Even simple and light movements appear strenuous and can lead to pain in the lungs or heart. Specific treatment is not possible. However, free fatty acids can be bound by albumins, which can reduce the symptoms of fat embolism. However, the complications and symptoms described above may also occur.
When should you see a doctor?
If you experience shortness of breath, rapid heartbeat, or other signs of fat embolism, call a doctor immediately. Chest pain and coughing attacks are also warning signs that need to be clarified quickly. If other symptoms occur, such as sweating, dizziness or signs of a cardiac arrhythmia, it is best to call an emergency physician. In the event of a circulatory collapse with shock, the affected person must also be attended to immediately by a medical professional. Small fat embolisms can usually be cleared by the body on its own. A medical examination is necessary if symptoms such as coughing, dizziness or mild chest pain occur repeatedly. If symptoms of a fat embolism occur, this must be examined immediately and treated if necessary. The general practitioner can make an initial guess and then refer the patient to a specialist who will initiate further therapeutic measures. During treatment, regular visits to the doctor are necessary so that complications can be ruled out. However, should adverse events occur, the emergency medical service can be contacted. If symptoms are severe, the patient should be taken to a hospital.
Treatment and therapy
Because the pathogenesis of fat embolism has not been fully elucidated, there is also no standard of care. The administration of corticosteroids favorably affects the prognosis of fat embolism. Albumins can bind the free fatty acids and thus have a beneficial effect. Heparin can also clear the blood plasma of lipids.
Outlook and prognosis
Fat embolism represents an acute health condition. Without medical care or immediate first-aid measures, the affected person may die prematurely. With prompt intensive medical care and subsequent good medical attention, relief of symptoms is possible. Freedom from symptoms can also be achieved. However, depending on the intensity of the symptoms experienced as a result of the fat embolism, lifelong impairments may occur. Long-term therapies are offered, which should lead to a steady improvement of the quality of life.With the patient’s cooperation, there is a good chance of reducing the symptoms. Overall, the patient’s lifestyle must be adapted to the possibilities offered after experiencing the emergency situation. In addition, the causes of the fat embolism must be healed and cured in parallel. This is normally achieved within a few months. Since bone fractures or damage are among the most common causes of fat embolism, this healing prospect must be considered on an individual basis. If further mental illnesses develop in addition to the physical symptoms due to the shortness of breath or the experience of the traumatizing condition, the prognosis worsens. The psychological sequelae can lead to a severe reduction in the quality of life and have a detrimental effect on various ways of life. In severe cases, the patient will suffer from the experiences until the end of life and will suffer from psychosomatic disorders.
Prevention
To prevent fat emboli from developing during surgery after fractures, pressure on the bone marrow should be kept as low as possible during surgery. This can be achieved with a vacuum procedure or with an external fixator.
Aftercare
The options for aftercare are severely limited in cases of fat embolism. This should involve a radical change in diet to prevent further formation of the fat droplets. In this case, a doctor can usually set a proper and healthy diet plan, according to which the affected person can follow. Possibly, the fat embolism also limits the life expectancy of the patient. After successful treatment of the disease, care should be taken to maintain a healthy lifestyle with a healthy diet so that the disease does not recur. Various types of sports can also be helpful in alleviating the symptoms and restoring the body’s performance. In many cases, those affected are dependent on taking medication to permanently alleviate the symptoms. It is important to ensure that the medication is taken regularly and in the correct dosage to prevent further complications. First and foremost, however, the trigger of the fat embolism should be identified so that the cause can be treated quickly. In the case of psychological upsets or depression, help and support from one’s family has a very positive effect on the further course of the disease.
What you can do yourself
Fat embolism often occurs after a fracture of marrow-containing bones or even after orthopedic or trauma surgery. Likewise, blunt trauma to the liver carries the risk of fat embolism. However, many diseases such as pancreatitis, myocardial infarction or viral hepatitis can also cause acute fat embolism. As a rule, these are acute cases that require immediate emergency medical care. Self-help measures are not considered for acute fat emboli. Even in less severe cases, there is usually pain in the lungs, and sufferers often experience panic attacks, anxiety and sweating, or even faint. Therapeutic measures usually consist of a vigorous supply of oxygen to compensate for the reduced lung function. In parallel, intensive medical care and treatment is indicated to intervene immediately if serious complications are imminent. Normally, catecholamines are used, administered under strict control of pulmonary arterial blood pressure. Because of the acute emergency situation, there is also no need for adjustment in everyday life. Because of the often nonspecific symptoms in low-grade fat emboli, a definitive diagnosis is often difficult, especially when there is neither dyspnea and high respiratory rate nor chest pain.
