Establishment And Evaluation Of Rat Model Of High Pressure Injection Injury

Objective: 1.To establish a stable,reliable and repeatable high-pressure injection injury(HPII)rat animal model.2.To evaluate the high-pressure injection injury rat animal model.Methods: 80 healthy adult rats were randomly divided into control group 20 and experimental group 60.The experimental group was counted as A,B,and C groups according to the vertical distance of the high pressure spray gun from the rat groin 1 cm,3cm,and 5 cm.Each group contains 20 rats.The control group received no special treatment,and the experimental group used high-pressure spray guns for high-pressure injection.Dynamic pressure sensors collected the pressure peaks,pressure rise times,and impulse of each group during injection to calculate the limb breakage and penetration of the rats after injury.The physical activity and blood circulation of the limb at 4h and 8h after the injury,the perfusion of the injection to the distal end of the limb,and the pathological examination after the injury.The data obtained were statistically analyzed using SPSS software.Results: 1.Peak injection pressure,pressure rise time and impulse change: There was no change in skin pressure in the control group,the peak pressure of group A was 2664.41 ±11.24 kpa,the pressure rise time was 1.19 ± 0.02 ms,and the impulse was 3.16 ± 0.07 kpa · s;The peak pressure of group B is 1444.14 ± 0.06 kpa,the pressure rise time is 1.25 ± 0.01 ms,and the impulse is 1.80 ± 0.05 kpa.s;the pressure peak of group C is 857.11 ± 0.06 kpa,the pressure rise time is 1.33 ± 0.14 ms,and the impulse is 1.13 ± 0.04 kpa · s.Compared with the control group,P<0.05 in the experimental group was statistically significant;compared with the experimental group,the peak pressure,pressure rise time,and impulse P<0.05 were statistically significant.2.Visual observation of limb dissection and penetration: control group rats had 0 limb injury,0 limb injury,group A rats with limb injury 0,limb injury 20,and group b limbs There were 0 sever wounds,0 penetrating injuries,and 0 rats in group c had stab wounds and 0 penetrating injuries.3.Physical activity after injury: After quantification of the slope test,compared with the control group,the phase P<0.05 at 4h and 8h in group A and group B was statistically significant,and the phase P at group C was> 0.05,no statistical significance;Compared with each time group in the three groups A,B,and C,P<0.05 was statistically significant;compared with each time group in group B,P<0.05,was statistically significant.Groups A,C,and each time group Compared with P> 0.05,there was no statistical significance.4.Limb blood circulation: Compared with the control group,the comparison between group A and group 4h and 8h was P<0.05,which was statistically significant,and the time period of group C was P> 0.05,without statistical significance;A,B Comparing P<0.05 in each phase group of three groups of C and C is statistically significant;comparing P<0.05 in each phase group of group B is statistically significant;the internal phases of each phase group of group A and C Ratio P> 0.05,no statistical significance.5.Perfusion of the injection to the distal limb: the control group had limbs intact,and the limbs of group A were penetrated.No injection was perfused through the injection hole along the tissue gap to the distal end of the limb,and group B saw the injection through the injection hole through the tissue gap to the limb.With distal perfusion,only skin breaks or scars were seen in the limbs of group C.6.Pathological examination: ⑴ Skin: 4 hours after the model was established in group A,the squamous epithelium was broken and disappeared at 8 hours.In group B,the squamous epithelium and skin appendages disappeared completely at 4h,and a lot of inflammatory cells,red blood cells and vacuole were observed in 8h interval.In group C,only part of the squamous epithelium was damaged in each phase.⑵ Muscle: muscle fiber edema was obvious in 4h,part of the gap disappeared,8h edema continued to worsen,and some muscle fibers were ruptured.Group B had more muscle fibers rupture in 4h,and a large number of muscle fibers were damaged in 8h.Broken,no abnormalities in group C.⑶Nerve: 4h edema,part of the cell nucleus became short rod-shaped or round,8h edema further worsened,the gap widened,and nerve tissue was broken.Group B edema ruptured and the gap was significantly widened at 4h The edema rupture was more obvious at 8h,the gap was extremely wide,and the tissue morphology completely disappeared.No abnormalities were seen in group C.⑷ Vascular: The vascular endometrium of group A was not smooth at 4h,and the nuclei were exposed in the lumen.Fracture.In group B,the whole layer of the lumen was broken at 4 hours,and the vessel intima was extremely uneven at 8 hours.Conclusion: When the vertical injection distance is 3cm and the pressure is 1440.14 ±35.47 kpa,the injection of the injection of the injection into the distal end of the limb through the injection hole along the tissue gap and progressive damage to the skin,muscles,nerves and blood vessels occurred.This parameter may be the best parameter for constructing a rat model of high-pressure injection injury,and a stable,reliable,and repeatable animal model of high-pressure injection injury can be prepared.