Spencer R C
Public Health Laboratory, Bristol Royal Infirmary, UK.
J Hosp Infect. 1999 Dec;43 Suppl:S127-35. doi: 10.1016/s0195-6701(99)90075-0.
Infections are often caused by bacteria that gain access either from the skin during insertion, or by migration from the skin to the surrounding subcutaneous tissue, once in situ. It is necessary to understand the pathogenesis with regard to sessile or planktonic forms of microorganisms and why they adhere to catheter surfaces, and the interactions between host, catheter and bug. To prevent colonization two general approaches have been adopted: the first concerns the site of insertion-prophylactic antibiotics, tunnelling, intraluminal antibiotic locks, topical application of antibiotics or antiseptics, cutaneous disinfection pre- and post-insertion with various antiseptics, catheter site care and frequency of dressing changes. The second approach considers the physical nature of catheter material-silver impregnated subcutaneous collagen cuffs, antiseptic hubs, antimicrobial coating of catheters with antibiotics e.g., rifampicin and minocycline, silver ions, chlorhexidine, chlorhexidine and silver sulphadiazine. Only by understanding the pathogenesis of catheter devices whereby micro-organisms are embedded in biofilms and are resistant to the action of antibiotics, will effective preventative measures be possible. In addition a proper risk-management review will be necessary to determine the cost-benefit of such modified catheters.
感染通常由细菌引起，这些细菌要么在导管插入过程中从皮肤进入，要么在导管就位后从皮肤迁移至周围皮下组织。有必要了解微生物固着或浮游形式的发病机制，以及它们为何附着于导管表面，还有宿主、导管和病菌之间的相互作用。为防止定植，已采用两种一般方法：第一种涉及插入部位——预防性使用抗生素、隧道式置入、管腔内抗生素封管、局部应用抗生素或防腐剂、插入前后用各种防腐剂进行皮肤消毒、导管部位护理及更换敷料的频率。第二种方法考虑导管材料的物理性质——含银皮下胶原袖套、抗菌接头、用抗生素（如利福平、米诺环素）、银离子、洗必泰、洗必泰与磺胺嘧啶银对导管进行抗菌涂层处理。只有了解微生物嵌入生物膜并对抗生素作用产生抗性的导管装置发病机制，才有可能采取有效的预防措施。此外，还需要进行适当的风险管理评估，以确定此类改良导管的成本效益。
