材料表面发热范围温度升高对于内植物相关感染的预防

Efficacy of medical device surface fever-range hyperthermia in prophylaxis of experimental Staphylococcus aureus device related-infection

目的观察在动物实验中,内植物材料表面温度发热范围升高能否降低内植物相关感染率。方法在兔背部两侧皮下各植入1个无菌组织笼子,内放置骨水泥包裹的发热体,两周后,注入金黄色葡萄球菌,分别给予材料表面发热和不发热,抽取组织液测定细菌浓度及计算感染率,测定白细胞浓度。结果在发热组,组织笼子感染率为34.4%(11/32);组织笼子内白细胞计数在发热组升高。在未发热组,实验结束时,感染率为75.0%(24/32);在未感染组织笼子内白细胞计数第一天后白细胞计数不再增高。感染组织笼子内白细胞计数达到105/μl,但是成活细胞仅有50%左右。结论材料表面发热范围的温度升高能够降低内植物材料相关感染率。

Objective To study whether medical device surface fever-range hyperthermia is effective in prophylaxis of device-related infections by using in vivo tissue cage infection model.Methods Positive temperature coefficient （PTC） was coated with polymethyl methacrylate （PMMA） as the medical surface fever resource. Two weeks after subcutaneously implantation of tissue cages contained PTC,approximately 0.2×106 CFU S. aureus ATCC 25923 was inoculated into the tissue cages. Each animal received 10mins twice-daily PMMA surface fever-range hyperthermia （SFRH） for 8 days,or was left untreated. The tissue cage fluid （TCF） was sterilely aspirated from each group each day. The bacteria quantity were enumerated,leukocyte and leukocyte viability rates were counted in TCF.Results In SFRH,the infectious rate was 34.3%,in non-infectious tissue cages,leukocytes reached （2.9±0.6）×104/ul at the first day,after this the leukocytes remained at this level. In untreated group,infectious rate was 75.0%,in non-infectious tissue cage,leukocytes were（2.5±0.4）×104/ul,decreased to baseline at 2nd day. In infectious tissue cages,the leukocytes reached 105 /ul,but the viability decreased to approximately 50%.Conclusion Medical device SFRH may decrease device-related infections through enhancing leukocyte-dependant host defense mechanism.