If a person is diagnosed with fat embolism (or ZhE), embolization is carried out with droplets of fat of the microvasculature. First of all, the pathogenic process affects the capillaries of the brain and lungs. This is manifested by hypoxemia and the development of acute respiratory failure, diffuse brain damage, ARDS of various degrees of severity. Clinical manifestations are most often observed 1-3 days after injury or other exposure.
If the case is typical, then the clinical signs of fatty embolism of the lungs and brain are characterized by gradual development and reach a maximum approximately two days after the first symptoms. A fulminant appearance is rare, but a fatal outcome can occur literally a few hours after the onset of pathology. In young patients, ZhE is more common, but mortality in older people is higher.
There is an opinion that when a patient is found while injured in a state of extreme intoxication, ZhE rarely develops. There are several theories regarding the mechanism of the appearance of fat embolism (biochemical, colloidal, mechanical), however, most likely, each specific case has different mechanisms that lead to ZhE. Fatal outcome is about 10-20%.
Types of disease
There is a certain gradation. Fat embolism is classified by the intensity of the manifestation of the clinical picture:
- acute: it is characterized by the manifestation of clinical signs within a few hours after receiving an injury;
- lightning fast: death with this form occurs in a few minutes;
- subacute: this species is characterized by the presence of a latent period of up to three days.
According to the severity of signs:
ZhE: frequent reasons
In approximately 90% of situations, the cause is a skeleton injury. Especially often - a fracture of large tubular bones, mainly - a femoral fracture in the middle or upper third. If there are multiple bone fractures, the risk of PVCs increases.
Rare causes of pathology
In more rare cases, the causes are as follows:
- hip prosthesis;
- closed reposition of bone fractures;
- intramedullary femoral osteosynthesis with large pins;
- major soft tissue injury;
- extensive surgery of the surgeon on the tubular bones;
- liposuction;
- severe burns;
- bone marrow biopsy;
- hepatic fatty degeneration;
- long-term treatment with corticosteroids;
- the introduction of fat emulsions;
- osteomyelitis;
- acute pancreatitis.
Symptoms of this dangerous ailment
Fat embolism is inherently a fat thrombus, which is either in a calm state, or moves through the vessels, penetrating into various organs. If a fatty thrombus enters the heart, then acute heart failure can develop, in the kidneys - failure of this organ, in the lungs - respiratory failure, in the brain of the head - stroke, etc. In some cases, the entry of a fatty thrombus into the heart cavity causes instant fatal the outcome.
For fractures
Most often, fat embolism in fractures begins to develop immediately after an injury, when particles of fat enter the blood vessels. Fat droplets gradually accumulate in the blood, and therefore, in the first hours after injury, this process takes place without obvious symptoms. Signs of it appear 24-36 hours after an injury or surgery. By this time, many capillaries are clogged. Small petechial hemorrhages form on the upper chest, on the neck, in the armpits and on the shoulders.
If the capillaries of the lung are clogged, then a dry cough, shortness of breath, cyanosis of the integument of the skin (cyanosis) appear. Characteristics of fat embolism of the heart are a violation of the heart rhythm, tachycardia (heartbeat too frequent). Confusion may also occur and temperature may rise.
The main signs of this pathology
Fat embolism manifests itself in the form of a number of signs.
- Hypoxemia of the arteries.
- Symptoms of ARDS (most often with a severe course of the disease).
- Violation of the central nervous system (convulsions, motor anxiety, coma, delirium), when oxygenation is normal, there is no apparent regression of neurological signs.
- Petechial rashes appear 24-36 hours after injury in patients in 30-60% of cases, their localization is in the upper body, and even more often in the armpits. It is characterized by an outpouring of blood on the oral mucosa, conjunctiva and ocular membranes. Most often, rashes go away within a day.
- A sharp decrease in hemoglobin levels on the second or third day.
- Thrombocytopenia, that is, a rapid decrease in platelet count and fibrinogen level.
- Detection of neutral fat in urine, blood, sputum, cerebrospinal fluid (fat is detected in alveolar macrophages).
- Detection during skin biopsy at the site of petechiae fat.
- Detection of retinal angiopathy with fat.
Below we consider the diagnosis of fat embolism.
Additional manifestations are of little importance. All of them can occur with any serious skeleton injury.
Instrumental examinations
- In many cases, MRI makes it possible to establish the causes of fatty embolism of the brain.
- Pulmonary radiography confirms the presence of ARDS, makes it possible to exclude pneumothorax.
- Cranial CT allows to exclude another pathology inside the skull.
- Monitoring Even with small manifestations of ZhE, pulse oximetry should be used, since the situation can change very quickly. If the lesions of the central nervous system are severe, then control of the pressure inside the skull is necessary.
Fat embolism treatment
What it consists of is interesting to everyone. Numerous therapeutic methods proposed to get rid of ZhE are not effective: the introduction of glucose in order to reduce the mobilization of free fatty acids, ethanol - to reduce lipolysis. Serious injuries are often accompanied by the occurrence of coagulopathy. Usually, “Heparin” is prescribed during the first three days (including also low molecular weight), which increases the risk of bleeding and increases the concentration of fatty acids in the plasma, and this treatment is not indicated.
There is no evidence that commonly prescribed drugs for the treatment of fatty acids, such as sodium hypochlorite, Contrical, Hepasol, Lipostabil, Essential, nicotinic acid can positively affect the pathology. Therefore, treatment mainly has a symptomatic focus.
The purpose of respiratory therapy is to maintain PaO2 values of more than 70-80 mm Hg. Art. and 90% ≤ SpO2 ≤ 98%. If the case is mild, then oxygen therapy through nasal catheters is sufficient. The occurrence of ARDS in patients needs special modes and approaches of mechanical ventilation.
If it is reasonable to limit the amount of infusion treatment and use diuretics, then you can reduce the accumulation of fluid in the lungs and decrease the ICP. Until the patient's condition stabilizes, saline solutions (Ringer's solution, 0.9% sodium chloride), albumin solutions are used. Albumin contributes to the effective restoration of the volume inside the vessels and to some extent reduces the intracranial pressure, and also, by connecting fatty acids, it can reduce the progression of ARDS.
If the patient has serious cerebral manifestations of fat embolism, then sedative treatment, artificial pulmonary ventilation are used. There is some correlation between the increase in ICP and the depth of the coma. The management of such patients resembles in many ways the management of people with traumatic brain damage of a different genesis. It is also required to prevent a temperature increase of more than 37.5 ° C, in connection with which non-steroidal analgesics are prescribed, as well as physical cooling methods, if necessary.
Prescribed drugs with a wide range of effects, most often third-generation cephalosporins - as a starting treatment. If coagulopathy significant from a clinical point of view develops, then freshly frozen plasma is used.
The effectiveness of the use of corticosteroids in the treatment of fat embolism in hip fractures has not been proven either. However, they are often prescribed because they think that they are able to prevent the progress of the process in the future. It is advisable to prescribe corticosteroids for ZhE in large doses. Bolus - "Methylprednisolone" from 10 to 30 mg per kg for 20-30 minutes. After that - with a dispenser of 5 mg / kg / hour for two days. In the absence of Methylprednisolone, other corticosteroids (Prednisolone, Dexamethasone) are used in equivalent doses.
Amputation Complications
Due to fat embolism during amputation, disturbances in the activity of internal organs (stroke, respiratory, cardiac, renal failure, etc.) can occur. In one percent, it can lead to fulminant death of a patient due to cardiac arrest.
Prevention of this dangerous pathology
What should be done to avoid this dangerous complication? Prevention of fat embolism is required for patients with fractures of the tubular bones of the legs and pelvic bones (in an amount of two or more). Preventive measures include:
- competent anesthesia;
- early and effective elimination of blood loss and hypovolemia;
- early surgical stabilization of pelvic fractures and tubular large bones in the first day is the most effective preventive procedure.
The frequency of complications in the form of ARDS and ZhE increases very much if the operation is delayed. It must be said that traumatic brain injury and chest injury are not considered a contraindication for conducting intramedullary early osteosynthesis of the tubular bones. There is also evidence of the effectiveness of corticosteroids for the prevention of fat embolism and post-traumatic hypoxemia, although the optimal doses and regimens have not been determined.