Objective To understand time-effect relationship in prehospital emergency care of trauma patients so as to cut down mortality. Methods The data of pre-hospital deaths of trauma pa-tients were collected from 67 Shenzhen Emergency Network Hospitals during 2002-2004 and input into a database established by using Foxpro 6.0.Then, the data were analyzed by software SPSS 11.0. Re-sults A total of 161 364 trauma patients received prehospital emergency call service during 2002-2004 and 3 967 patients died prehospital or in hospital.There were 360.528 and 645 trauma patients died pre-hospitsl in 2002, 2003 and 2004 respectively, accounting for 32.57%, 37.69% and 44.25% respec-tively of whole trauma emergency patients in corresponding year.In 2002, 2003 and 2004 respectively, pre-hospital mortality was 1.15%, 0.88% and 0.99%, ratio of male to female 79.17/20.83, 77.65/22.35 and 71.63/28.37, the death age(29.04 ±13.98), (27.84±18.54)and(29.25±17.06)years old, ratio of traffic trauma to non-traffic trauma 48.33/51.67.26.14/73.86 and 37.98/62.02, the median response time of ambulance in hospital 2, 2 and 1 minute, the median time of ambulance arri-ving at the accident scene 5, 8.5 and 7 minutes and the median time of ambulance to and fro was 15.35 and 30 minutes. Conclusions There is a tendency that the number of the pre-hospital deaths of trauma patients increases, but that the ratio of traffic to non-traffic trauma and mortality decrease.The average age of dead trsuma patients is 10 years younger than that of whole emergency patients in the city of Shenz-hen.The response time of ambulance in hospital shortens, but the time of ambulance arriving accident 8cene and to and fro time of ambulance prolong.

Objective:To establish silicone cartilage models of donor-sites for the microtia patients by using digital technology, and to explore the application of surgical simulation in auricular reconstruction.Methods:From June 2018 to October 2019, 19 congenital microtia patients underwent thoracic CT scans and following three-dimensional costal cartilage imaging with Mimics software at the Nanfang Hospital, Southern Medical University. Among these patients, 16 were males and 3 were females. The mean age of patients was 16 years (range 8 to 35 years). Silicon cartilage models were produced by 3D printing and used for surgical planning and preoperative simulation in ear framework fabrication. Cartilaginous framework was sculptured according to the simulation during operation. Patients were followed up for a minimum of six months to evaluate the size, outline, height and auriculocephalic angle of the reconstructed ear. The satisfactory outcomes of the patients were scored according to a 5-point Likert scale.Results:All the patients received the surgical simulation and sculpture training with silicone cartilage models before operation. Auricular reconstruction was completed successfully according to the simulation. The duration of sculpture was shortened to 1-1.5 hours. There were no serious complications, such as hematoma, inflammation, skin necrosis and framework exposure. The contour of reconstructed ear was natural and clear over a 6 months follow-up, and all the patients were satisfied with their surgical outcomes.Conclusions:With the application of digital technology and silicone cartilage models by 3D printing to the surgical planning and training in microtia patients, patient-specific framework is fabricated with precisely assembling, which not only shortens the operation time, but also provides the unexperienced surgeons with a safe and effective training of ear framework fabrication.