Fat embolism syndrome is one of the common complications after major orthopedic surgery and severe fracture trauma, its onset is acute, early symptoms and signs are atypical and lack of objective indicators, easy to be ignored by clinicians, high mortality rate, early detection to establish a diagnosis plus early treatment is crucial, our hospital from 1994 to 2008, a total of 21 cases, is now retrospective analysis of the following. 1, clinical information 1.1 general information in this group of male 13 cases, female 8 cases, age 16-75 years old, the average age of 45.2 years. There were 16 cases of trauma, 3 cases of total hip replacement, 2 cases of spinal surgery, 9 cases of multiple fracture, 2 cases of pelvic fracture, 3 cases of femoral stem fracture, 2 cases of tibiofibular fracture, of which there were 7 cases of open injuries and 9 cases of closed injuries. 10 cases occurred after the injury, 7 cases occurred after the operation, and 1 case occurred in the operation of intramedullary pin fixation, and the patients’ symptomatic time appeared in the time of 8h～7d after the injury or the operation, with the average of 43h. 1.2 Early clinical manifestations In this group, 1 case occurred in the operation, and the remaining 20 cases were sudden shortness of breath, irritability, respiratory rate up to 36-54 times/min after trauma or surgery, accompanied by headache, irritability, irritability, paranoia, drowsiness and other central nervous symptoms, and there were 5 cases who turned to coma after about 0.5-1h, with a continuous decrease in PaO2, heart rate >120 times/min, and body temperature >38.5℃. Among them, platelets and hemoglobin decreased progressively in 5 cases, typical hemorrhagic spots appeared in axilla, prothorax and lid conjunctiva in 3 cases, fat plugs were seen in sclera in 2 cases, urine fat droplets were positive in 2 cases, lung X-ray showed “blizzard”-like changes in 4 cases, and cranial CT and MR did not find any definite lesions, and 11 cases showed hypoxia on early blood gas analysis, and 9 cases showed obvious blood sedimentation, and 11 cases showed hypoxia. Eleven cases showed hypoxemia in early blood gas analysis, and nine cases showed a significant increase in blood sedimentation. 1.3 Early establishment of diagnosis refers to Gurd’s early diagnostic index [1], i.e., it includes 3 primary criteria (punctate hemorrhage, respiratory symptoms, cerebral symptoms without craniocerebral injury), 2 secondary criteria (partial pressure of blood oxygen <60mmHg, hemoglobin <10g/dl), and 7 reference criteria (pulse >120/min, temperature >38℃, blood sedimentation >70mm/h, platelet drop, positive urine fat droplets, increased serum lipase, increased blood FFA). FES can be diagnosed with 2 major criteria, or 1 major criterion, 4 minor criteria and reference criteria, but if the diagnosis is confirmed according to this criterion and then treatment is given, the condition is often already very serious or the prognosis is unfavorable, and early diagnosis depends on close clinical observation, followed by auxiliary examinations, including arterial oxygen partial pressure measurement, chest X-ray, cryogenic examination of fat droplets in clotted blood, serum esterase test, urine and sputum lipid droplet examination, and so on. and sputum lipid droplet examination. For suspected cases, high attention should be paid to early prophylactic application of methylprednisolone. 1.4 Timely treatment After the clinical diagnosis of FES is established, the traumatized limb should be temporarily fixed with plaster or splint, and high dose of MP should be applied to shock and expand blood volume, according to the therapeutic experience and the drug description, the usage of MP is: 500mg/times, 2 times/d for 4d, the dose is reduced by half, and then continue for 3d. at the same time, with the treatment of hyperbaric oxygen, and other therapeutic measures include keeping the airway open, oxygenation, and if necessary, the use of methylprednisolone should be taken into consideration. Other therapeutic measures include keeping the respiratory tract open, oxygenation, mask oxygen or tracheotomy artificially assisted mechanical ventilation if necessary, mannitol and low molecular dextrose anhydride, etc. According to the condition, diuretics were given as appropriate, rehydration in a timely manner, transfusion of blood to maintain the balance of water and electrolytes, anti-infection and supportive therapies, and surgical treatment was carried out for the patients with open injuries and vascular injuries in the course of the antiresorptive treatment. 2, results 3 cases died of respiratory failure in this group, the remaining 18 cases received timely treatment, without leaving any neurological sequelae, 10 patients in the condition of recovery within 1 month after orthopedic surgery. 3, Discussion 3.1 Once fat embolism syndrome occurs, the condition is urgent, and being able to achieve early diagnosis is the key to reducing mortality. Through the rescue experience of this group of data and relevant literature reports, we mainly establish early diagnosis based on the following aspects: firstly, based on the medical history that is, the original disease such as femur, tibia or pelvic fracture, especially due to high-energy injuries caused by the simultaneous accompanied by hypovolemic shock multiple fracture patients that is in a high-risk state.