Causes of pulmonary fat embolism Fat embolism syndrome (FES) is the most serious complication after trauma or operation in patients with fracture. The main lesion is lung, and lung lesion is the basis of FES. It is more common in long bone fractures of lower limbs, and the incidence of bilateral femoral shaft fractures can be as high as 33%. Can occur at any age, more common in adults, more men than women, the elderly are seriously ill. The influencing factors are: early surgical fixation or selection of plaster and traction conservative treatment after fracture; Whether it is complicated with chest injury, etc.
The pathogenesis of FES is not completely clear at present. It is generally believed that the medullary cavity is destroyed when the shaft fractures, and a large amount of bone marrow fat overflows into the hematoma. When the pressure in the hematoma is higher than that in the vein, fat drops enter the blood stream with the rupture of the venous sinus. Raise the affected limb during disinfection and dressing change, increase venous reflux, or puncture the hematoma barrier when moving the broken end, which increases the chance of fat droplets entering the blood stream.
In addition, normal lipid emulsification is in an unstable state during fracture, which can aggregate into larger lipid droplets and enter the blood stream. Is the droplet diameter greater than 20? M will stay in pulmonary vascular bed, block pulmonary blood vessels, stimulate vascular endothelial cells to release lipase, and neutral lipid droplets will be hydrolyzed into free fatty acids (FFA) and glycerol under the action of lipase. Blocked pulmonary vessels are stimulated by FFA toxicity, resulting in toxic or chemical vasculitis; Vascular endothelial cells swell and deform and separate from the basement membrane, thus destroying the integrity of vascular endothelial cells; Increase its permeability, blood extravasation, causing alveoli to be filled with foamy bloody liquid, causing diffuse interstitial pneumonia and acute pulmonary edema, thus seriously interfering with the ventilation function of alveolar membrane; Because exudate accumulates in alveolar cavity, it destroys surfactant on alveolar surface, reduces lung compliance, and finally leads to life-threatening arterial hypoxemia.
In addition, a large number of platelets gather and deform at the fat drop embolism, which increases the mechanical obstruction of pulmonary blood vessels and releases active substances to aggravate hypoxemia, resulting in pulmonary fat embolism syndrome in clinic.
The disease is most likely to occur within 3 ~ 5 days after fracture and within 24 ~ 48 hours after early injury. The onset to death of this group is only 2 hours after injury, which is explosive FES. It is related to serious injury, bilateral femur and right tibia and fibula fractures, and regular exercise. In case 2, whenever the affected limb moved to change dressing, symptoms appeared, which were confirmed by X-ray and CT as pulmonary fat embolism. Case 1 and 3 were compared by X-ray and CT before and after onset, and the lung lesions were basically absorbed within 4 days after treatment. It is worth noting that cases 1 and 3 have enlarged hearts at the onset, suggesting cardiac insufficiency, which is consistent with Tan's report. X-ray and CT can show diffuse pulmonary edema. The author thinks that, as mentioned in the pathogenesis, FES can induce acute pulmonary edema. This may be helpful for the treatment of severe pulmonary fat embolism syndrome in the future. At present, there is no specific treatment for this disease. Case 3 and case 4 showed fat thrombus deposition in mediastinal fat shadow, which has not been reported before, and may be one of the signs of FES. Because of the small number of cases, further observation is needed. X-ray and CT are of great value in the diagnosis and dynamic observation of this disease. Clinically, when patients with long bone fracture suddenly have dyspnea and changes in consciousness, they should think of this disease, combine laboratory examination with X-ray or ct examination, make a correct diagnosis as soon as possible and deal with it in time.
Knowledge expansion of causes of pulmonary fat embolism: prevention and treatment of pulmonary tuberculosis 1. Early detection of new patients.
Tuberculosis infection mainly occurs before patients are found and treated. Average 1 TB patient (i.e. source of infection) can be infected 15 people. Because the new patients did not take any preventive measures before discovering the disease, in the process of close contact with family members, colleagues and classmates. Contacts are prone to tuberculosis. Therefore, the first measure to prevent tuberculosis is to find new patients hidden in the crowd as soon as possible.
2. Thorough treatment to shorten the infection period.
Early detection of new patients can bring many benefits to treatment:
☆ There are many drugs to choose from.
The treatment cost is low.
☆ Less adverse drug reactions and higher safety.
☆ Patients are easy to tolerate, the treatment can be carried out smoothly, and the possibility of cure is great.
☆ Reduce the failure rate of treatment
Its fundamental purpose is to thoroughly treat patients and shorten their infection period. Therefore, thorough treatment of patients is an important measure to effectively prevent tuberculosis.
3. Let people infected with tuberculosis reduce the incidence.
About 10% of TB patients may develop tuberculosis, and the onset mainly depends on the resistance of infected people and the number of TB patients. Ways to reduce the risk of disease are:
1) life rules. Avoid long-term overwork and mental stress, eat a balanced diet, exercise properly, and enhance resistance.
2) Prevention of tuberculosis-related diseases. Diabetes, for example, will quadruple the chance of tuberculosis. Another example is AIDS, which will increase the risk of tuberculosis by 30 times. Others such as silicosis, gastrointestinal diseases, tumors, organ transplantation, long-term use of glucocorticoid, etc.
3) Change bad living habits. ① Quit smoking. The more smokers there are, the greater the chance of getting tuberculosis. Cough and expectoration caused by smoking are also easy to cover up the symptoms of tuberculosis and affect the timely detection and treatment of tuberculosis. 2 limit alcohol. Excessive drinking will lead to malnutrition and decreased resistance, and alcohol will damage the liver. Once suffering from tuberculosis, it can increase the toxicity of anti-tuberculosis drugs to the liver and affect the treatment. ③ Avoid staying up late for a long time.
4) Preventive treatment for high-risk groups. The focus of prevention and treatment is on infected children in the families of newly discovered tuberculosis patients, especially children under 5 years old and tuberculin test reaction? 15mm or components with blisters.
4. Prevent the spread of tuberculosis.
1) Reduce the spread of tuberculosis. (1) Strengthen health education, let everyone know about the harm and infection mode of tuberculosis, and form a hygienic habit that everyone does not spit everywhere. ② Sputum of tuberculosis patients should be burned or disinfected with drugs. ③ When coughing or sneezing, the patient should cover his mouth with a handkerchief or wear a mask, and don't speak loudly to others at close range. ④ The spittoons, sheets, pillow towels, quilts, masks, handkerchiefs, clothes, tableware and toiletries used by patients should be disinfected and cleaned frequently.
2) Reduce the concentration of mycobacterium tuberculosis in the environment. Tuberculosis is easy to spread in a closed environment with poor ventilation (such as indoor rooms, crowded dormitories or work sheds in winter). Therefore, it is necessary to develop the habit of regularly opening windows for ventilation and try to let sunlight into the room.
3) Pay attention to isolation and reduce contact with infectious sources. Patients with bacteria-expelling pulmonary tuberculosis should be isolated, and patients should not go to places with dense people and frequent contact with each other for activities or work. Family members found that in addition to active treatment and regular ventilation, patients with pulmonary tuberculosis had better live in a room alone, and sleep in separate beds if there are no conditions.
5. Vaccinate children with BCG.
Inoculation of BCG can make children have a certain level of specific resistance, reduce the chance of infection, or limit the growth and reproduction of bacteria when infected with natural tuberculosis, reduce the number of bacteria, and play a role in preventing tuberculosis in children, especially tuberculous meningitis and severe disseminated tuberculosis. The vaccination target is newborns.
Conclusion: In the above article, I introduced five methods to prevent and treat tuberculosis. I believe everyone has some understanding after reading it. I hope everyone has a good living habit and eating habit in their daily life. Finally, I wish you all a long and healthy life.