Establishment Of Insertion Infection Model And Role Of High Requency Electric In Prevention Of Infection In Rabbits

Objective To design and establish an animal model of insertion infections after operation and to observe the quantity of the becterium and the change of the correlate index when the rabbits'insertion was infected after operation , and to study the role of high requency electric in prevention of infection in rabbits.Methods To take fifty-one healthy ripe rabbits of common level as investigative object, the forty-eight rabbits of which were divided into A,B,C and D groups at random and there were tewele rabbits in every group, A,C were divided as the control groups and B,D were divided as experimental groups.The hibateral femurs of rabbits were taken out of completely after the surplus three rabbits were put to death, the insertion was designed and made on the basis of the anatomic form and length of rabbits femurs. Rabbits were anesthetized by 3% pentobarbital solution through ear vein and the dosage was 1ml/kg .the anthropogentic fracture was caused to happen under germ free state, the infection strain of Staphylococcus aureus(ATCC25923)in hospital was inoculated in the surrounding of insertion and place of fracture, which was to achieve purpose of insertion infections, the 1×104CFU quantity of the bacterium was inoculated into the A and B groups and 1×106CFU into the C and D groups, and the curing equipment of high frequency electric(small high frequency electrical surgery unit) was exerted on insertion, high frequency electric was applied in operation after bacterium being inoculated immediately in the experimental groups and there were one-week healing with 75W everyday after operation,but there had no healing in the control groups . An observation was done on the cut healing status, X-ray graphs, bacteria cultures, pathological changes and levels of serum CRP and ESR after operation.Results Three after operation.①General state of health: There were 8 in the control A group,12 in the control C group,1 in the experimental B group and 3 in the experimental D group, whose wound accreted infaustly, the sinuses, 1 in the control A group and 3 in the control C group, were formed with effusion effusing.②Bacteriology detection: 75%(9/12)in the control A group, 100%(12/12)in the control C group, 16.67%(2/12)in the experimental B group, 33.33%(4/12)in the experimental D group were infected in rabbits, the differences between the control A,C groups and the experimental B,D groups were all obviously statistical significance(P<0.05),③Radiological examination: In infection rabbits, there was not callus in place of fracture and the fracture was dys-healing after three week of operation ;④Histology change: the fibroblast and the inflanmatory were to be full of the infected insertion with HE staining, which the inflanmatory were as host ; the quantity of Staph Staphlococci was dispersed into the tissue of the infected insertion with Gram's staining.⑤CRP,ESR detection: According to the result of CRP detection, rabbits CRP were stepped up noticeably in one day after operation in the four groups(P<0.05),after operation, the level of CRP were sustained higher in three weeks in the control A and C group, and that were descented noticeably in two weeks in the experimental B and D group, which got close to normal level in three weeks. According to the result of ESR detection, rabbits ESR were stepped up in one day after operation in the four groups(P<0.05),achieving peak in one week. the level of ESR were descented slowly in one week in the control A and C group after operation, which were sustained higher in three weeks, and the level of ESR in two weeks in the experimental B and D group was much slower and obviously decrease than that of he control A and C group(P<0.05).Conclusions An animal model of insertion infections after operation can be established successfully three week after the infection strain of Staphylococcus aureus(ATCC25923)of 1×106CFU is injected into the surrounding of insertion and place of fracture, the curing equipment of high frequency electric(small high frequency electrical surgery unit) is utility of prevention infection of insertion.