Opilla Marianne
Nutrishare, Inc, Elk Grove, CA, USA.
Am J Infect Control. 2008 Dec;36(10):S173.e5-8. doi: 10.1016/j.ajic.2008.10.007.
Catheter-related bloodstream infections (CR-BSIs) occur in 1.3% to 26.2% of patients with central venous catheters used to administer parenteral nutrition (PN). Because of their nutritional components, PN solutions can support microbial growth. Contamination during preparation and handling is rare in hospitals and home-infusion pharmacies but may be difficult to control in a home setting. The risk of infection is increased in hospitalized patients because of malnutrition-associated immunosuppression, hyperglycemia exacerbated by dextrose infusion, microbial colonization/contamination of catheter hubs and the skin surrounding insertion site, and poor nursing care. During long-term catheter use for PN, an intraluminal biofilm, catheter-tip fibrin sheath or tail, or central venous thrombosis creates sites for microbial seeding and infection. Chronic conditions and psychosocial issues also increase the risk of infection. In hospitalized patients with BSIs, the most common organisms are coagulase-negative staphylococcus, Staphylococcus aureus, Enterococcus, Candida spp, Klebsiella pneumoniae, and Pseudomonas aeruginosa. In the long-term PN population, approximately 60% of CR-BSIs are caused by coagulase-negative Staphylococcus.
The best plan of care for a suspected or known infected catheter in a hospitalized patient is to reinsert a new central line after 48 hours of antibiotic treatment and negative blood cultures. In patients who receive long-term PN, hospitalization increases the risk of a nosocomial infection because the catheter can be contaminated by staff. A patient with fungemia must always be admitted and catheter removed. With gram-positive and gram-negative organisms, the catheter may not need to be removed. In most patients receiving PN at home, removing a long-term venous-access device is challenging. Peripheral vein access or peripherally inserted central catheters are needed until a new permanent device can be inserted after negative blood cultures are obtained. Evaluation of remote site infection also is necessary. Strategies to reduce or prevent infection include catheter lock therapy, daily evaluation of continued need for PN, enteral rather than PN support, and avoiding overfeeding. More studies are needed to demonstrate conclusively the benefits of immunonutrition, such as the use of omega-3 or glutamine supplements to reduce CR-BSIs in patients receiving PN.
在接受肠外营养（PN）的中心静脉导管患者中，导管相关血流感染（CR-BSIs）的发生率为1.3%至26.2%。由于PN溶液的营养成分，其可支持微生物生长。在医院和家庭输液药房中，配制和处理过程中的污染很少见，但在家庭环境中可能难以控制。由于营养不良相关的免疫抑制、葡萄糖输注加剧的高血糖、导管接头和插入部位周围皮肤的微生物定植/污染以及护理不佳，住院患者的感染风险增加。在长期使用PN导管期间，管腔内生物膜、导管尖端纤维蛋白鞘或尾状物或中心静脉血栓形成会为微生物接种和感染创造部位。慢性疾病和社会心理问题也会增加感染风险。在发生血流感染的住院患者中，最常见的病原体是凝固酶阴性葡萄球菌、金黄色葡萄球菌、肠球菌、念珠菌属、肺炎克雷伯菌和铜绿假单胞菌。在长期接受PN的人群中，约60%的CR-BSIs由凝固酶阴性葡萄球菌引起。
对于住院患者中疑似或已知感染的导管，最佳护理方案是在抗生素治疗48小时且血培养阴性后重新插入新的中心静脉导管。在接受长期PN的患者中，住院会增加医院感染的风险，因为导管可能会被工作人员污染。真菌血症患者必须始终住院并拔除导管。对于革兰氏阳性菌和革兰氏阴性菌感染，导管可能无需拔除。在大多数在家接受PN的患者中，拔除长期静脉通路装置具有挑战性。在获得血培养阴性结果后插入新的永久性装置之前，需要外周静脉通路或经外周静脉穿刺中心静脉导管。对远处部位感染的评估也很有必要。减少或预防感染的策略包括导管封管治疗、每日评估是否继续需要PN、肠内营养而非PN支持以及避免过度喂养。需要更多研究来确凿证明免疫营养的益处，例如使用ω-3或谷氨酰胺补充剂来降低接受PN患者的CR-BSIs。
