Diagnosis and prevention of catheter-related infections

PURPOSE OF REVIEW: To highlight the major advances in diagnosing and preventing catheter-related infections published in research articles published between March 2004 and May 2007. RECENT FINDINGS: The challenge remains to make the diagnosis of catheter-related infection with good accuracy without catheter removal. The differential time to obtain positive qualitative blood culture appeared to be the most accurate available technique. Many catheter-related bloodstream infections are preventable. Simple interventions are often useful and multimodal programs are very efficacious, particularly in the intensive care setting. For long-term catheter-related bloodstream infection prevention, patient education appeared promising. Interesting evidence suggested that anticoagulant, by decreasing the biofilm formation, could decrease the risk of infection. For short-term central venous catheter-related infections research is ongoing on antiseptic dressings. Antiseptic lock appeared promising for preventing long-term central venous catheter bloodstream infections. SUMMARY: Nowadays, multimodal programs of catheter infection prevention are efficacious. Levels of catheter-related bloodstream infection of more than one or two per 1000 catheter-days are usually only found in the intensive care unit. It is a prerequisite to evaluate the cost-effectiveness of new techniques of prevention. As catheter-related bloodstream infections become rarer, strategies limiting unnecessary removal of catheters need to be developed and tested.     

Strategies for prevention of catheter-related bloodstream infections

 Prevention of catheter-related bloodstream infections is critically dependent on an accurate knowledge of the two main routes by which intravascular devices become contaminated: the extraluminal (skin-related) and the intraluminal (hub-related) routes. Extraluminal catheter seeding results from infection of the catheter entry site by microorganisms and leads to bacteremia most often during the week following catheter placement. The main ways of preventing it are appropriate skin disinfection and the adoption of maximal antiseptic barriers at the time of catheter insertion. Avoiding the internal jugular and the femoral veins, whenever possible, will reduce the likelihood of bacteremia. Intraluminal contamination is the consequence of improper handling of the catheter hub at the time of connection and disconnection of the administration set. It is the most common origin of catheter infections after the first week of catheter placement. Multiple-lumen catheters, side-ports and multipurpose catheters particularly increase the risk of endoluminal contamination. To prevent it, strict asepsis should be observed in hub handling and hubs should be protected against environmental soiling with an antiseptic impregnated gauze at all times. New technology is available for prevention of catheter infections: antibiotic and antiseptic-coated catheters, antiseptic hubs, disinfecting caps and flushing solutions are currently undergoing scientific assessment. Published online: 22 July 1999     

Antimicrobial-impregnated catheters for the prevention of catheter-related bloodstream infections

Central venous catheters are commonly used in critically ill patients. Such catheterization may entail mechanical and infectious complications. The interest in catheter-related infection lies in the morbidity, mortality and costs that it involved. Numerous contributions have been made in the prevention of catheter-related infection and the current review focuses on the possible current role of antimicrobial impregnated catheters to reduce catheter-related bloodstream infections (CRBSI). There is evidence that the use of chlorhexidine-silver sulfadiazine (CHSS), rifampicin-minocycline, or rifampicin-miconazol impregnated catheters reduce the incidence of CRBSI and costs. In addition, there are some clinical circumstances associated with higher risk of CRBSI, such as the venous catheter access and the presence of tracheostomy. Current guidelines for the prevention of CRBSI recommended the use of a CHSS or rifampicin-minocycline impregnated catheter in patients whose catheter is expected to remain in place > 5 d and if the CRBSI rate has not decreased after implementation of a comprehensive strategy to reduce it.     

Clinical review: new technologies for prevention of intravascular catheter-related infections

Intravascular catheters have become essential devices for the management of critically and chronically ill patients. However, their use is often associated with serious infectious complications, mostly catheter-related bloodstream infection (CRBSI), resulting in significant morbidity, increased duration of hospitalization, and additional medical costs. The majority of CRBSIs are associated with central venous catheters (CVCs), and the relative risk for CRBSI is significantly greater with CVCs than with peripheral venous catheters. However, most CVC-related infections are preventable, and different measures have been implemented to reduce the risk for CRBSI, including maximal barrier precautions during catheter insertion, catheter site maintenance, and hub handling. The focus of the present review is on new technologies for preventing infections that are directed at CVCs. New preventive strategies that have been shown to be effective in reducing risk for CRBSI, including the use of catheters and dressings impregnated with antiseptics or antibiotics, the use of new hub models, and the use of antibiotic lock solutions, are briefly described.     

Clinical review: New technologies for prevention of intravascular catheter-related infections

Intravascular catheters have become essential devices for the management of critically and chronically ill patients. However, their use is often associated with serious infectious complications, mostly catheter-related bloodstream infection (CRBSI), resulting in significant morbidity, increased duration of hospitalization, and additional medical costs. The majority of CRBSIs are associated with central venous catheters (CVCs), and the relative risk for CRBSI is significantly greater with CVCs than with peripheral venous catheters. However, most CVC-related infections are preventable, and different measures have been implemented to reduce the risk for CRBSI, including maximal barrier precautions during catheter insertion, catheter site maintenance, and hub handling. The focus of the present review is on new technologies for preventing infections that are directed at CVCs. New preventive strategies that have been shown to be effective in reducing risk for CRBSI, including the use of catheters and dressings impregnated with antiseptics or antibiotics, the use of new hub models, and the use of antibiotic lock solutions, are briefly described.     

The cost of catheter-related bloodstream infections: implications for the value of prevention

Catheter-related bloodstream infections (CRBSIs) are frequently observed in the intensive care unit (ICU) and are a serious cause of morbidity and mortality in the United States. This article summarizes what is currently known about the cost of CRBSIs in the ICU setting. The cost of CRBSIs is between $33,000 and $44,000 in the general adult ICU, between $54,000 and $75,000 in the adult surgical ICU, and approximately $49,000 in the pediatric ICU. Finally, CRBSIs are associated with reimbursement that is more than $26,000 less than costs. Hospital and clinical decision makers should be aware of the high cost of CRBSIs in the ICU, the relatively poor reimbursement, and the implied high value of prevention efforts.     

中心静脉导管相关性感染

目的：探讨导管相关性感染(CRI)的病原学及临床特点。方法：回顾分析2001年1月-2003年6月期间我院1327例次中心静脉置管病例中确诊的24例CRI病例，分析其病原体分布，感染与静脉导管留置类型、时间的关系。结果：CRI病例中，留置单腔导管者9例，留置双腔导管者15例。共分离菌株25株，其中革兰阳性菌12株．革兰阴性菌7株．真菌6株。金黄色葡萄球菌最多见(7株)，其次是真菌(6株)。CRI以置管后第8～14天发生率最高(56％)。结论：预防的重点在于避免导管腔内及腔外的污染。重视穿刺点皮肤的消毒，选用单腔导管，减少不必要的间置装置，操作者水平的提高以及抗生素的合理应用均能有效减少CRI的发生。对怀疑CRI者不应立即拔管，可先试行抗生素锁治疗，在24～48h后无效者应立即拔除导管。对于免疫功能低下、感染不易控制、病情严重以及金黄色葡萄球菌或真菌感染的病例。应及时拔除导管。     

导管相关性血流感染的原因分析与预防控制

中心静脉置入导管是危重病人及肿瘤术后化疗病人治疗的重要途径,随着血管内导管使用,与之相关的并发症也随之而来,最严重的是导管相关性血流感染(catheter related bloodstream infection,CRBSI).我们通过对1998年3月-2009年3月所在科室实施的850例多途径中心静脉置管术进行分析,对其中出现的7例CRBSI病例进行了原因分析.现报告如下.     

国内集束化护理预防深静脉导管相关性血流感染效果的Meta分析

目的 系统评价集束化护理干预对预防深静脉导管相关性血流感染的效果.方法 应用计算机检索国内相关文献,采用RevMan5.2软件进行统计处理.结果 共纳入13篇符合条件的文献.其合并OR值为0.33,95％CI为(0.26,0.43),说明集束化护理干预可以显著降低深静脉导管相关性血流感染的发生率.结论 集束化护理是一种切实可行的干预措施,值得在临床上推广.     

集束化策略在防止中心静脉导管相关性血流感染中的应用

中心静脉置管在临床运用日渐广泛,然而,由其带来的中心静脉导管相关性血流感染(central venous catheter-related blood stream infection,CRBSI)也成为临床最主要和最常见的并发症之一,其发病率已达到5%～30%[1],感染病人中病死率为12%～25%[2],且感染最常见的病原微生物是金黄色葡萄球菌和白色念珠菌[3].因此,实施严格的感染控制规范来防止CRBSI的发生是临床亟待解决的问题.     

New tools in diagnosing catheter-related infections

Clinical criteria alone are insufficient to allow a diagnosis of intravascular catheter-related sepsis (CRS). A definite diagnosis of CRS usually requires removal of the catheter for quantitative catheter tip culture. However, only about 15-25% of central venous catheters (CVC) removed because infection is suspected actually prove to be infected, and the diagnosis is always retrospective. Other diagnostic tests, such as differential quantitative blood cultures from samples taken simultaneously from the catheter and a peripheral vein, have been proposed to avoid unjustified removal of the catheter and the potential risks associated with the placement of a new catheter at a new site: a central-to-peripheral blood culture colony count ratio of 5:1 to 10:1 is considered indicative of CRS. Despite its high specificity, the latter diagnostic technique is not routinely used in clinical practice because of its complexity and cost. The measurement of the differential time to positivity between hub blood (taken from the catheter port) and peripheral blood cultures might be a reliable tool facilitating the diagnosis of CRS in situ. In an in vitro study, we found a strong relationship between the inoculum size of various microorganisms and the time to positivity of cultures. When the times to positivity of cultures of blood taken simultaneously from central and peripheral veins in patients with and without CRS were examined, we found that earlier positivity of central vs peripheral vein blood cultures was highly correlated with CRS. Using a cut-off value of +120 min, the "differential time to positivity" of the paired blood samples, defined as time to positivity of the peripheral blood minus that of the hub blood culture, had 91% specificity and 94% sensitivity for the diagnosis of CRS. This method may be coupled with other techniques that have high negative predictive value, such as skin cultures at the catheter exit site. This diagnostic test can be proposed for routine clinical practice in most hospitals using automatic devices for blood cultures positivity detection. Endoluminal brushing of the catheter is considered sensitive and specific for the diagnosis of CRS, but the risk of embolisation or subsequent bacteraemia should be considered. Gram staining and the acridine-orange leucocyte cytospin test on through-catheter blood culture have been proposed for rapid diagnosis of CRS without catheter removal. The technique, which requires 100 microl catheter blood and the use of light and ultraviolet microscopy, is considered simple, rapid (30 min) and inexpensive. In conclusion, diagnostic tools such as paired blood cultures or Gram staining and the acridine-orange leucocyte cytospin test should allow a diagnosis of CRS without catheter removal in cancer patients.     

Pediatric catheter-related bloodstream infections: latest strategies to decrease risk

Central venous catheters are often mandatory devices when caring for critically ill children. They are required to deliver medications, nutrition, and blood products, as well as for monitoring hemodynamic status and drawing laboratory samples. Any foreign object that is introduced to the body is at risk for infection. Central venous catheters carry a particularly high risk of infection and these infections can be life threatening. Advanced practice nurses possess the power to influence catheter-related line infections in their critical care units. Understanding current recommendations for catheter material selection, site selection, site preparation, and site care can affect rates of catheter-related bloodstream infections. This article discusses risk factors for developing catheter-related bloodstream infections in critically ill children, as well as measures to decrease incidence of catheter-related bloodstream infections, including a review of recommendations from the Centers for Disease Control and Prevention.     

PICC导管感染相关因素的研究现状

PICC导管作为静脉输液的安全通道已在临床广泛使用，患者在留置导管期间发生的感染并发症越来越受到医护人员的重视。针对引起感染的药物因素、患者因素、导管因素、操作因素和护理因素，提出了相应的预防对策，最大限度降低PICC导管感染的发生，提高护理工作效率及质量。     

浅谈介入导管相关性血流感染的预防与控制

由于介入放射疗法具有微创、简便、安全、有效的特点,并为一些传统疗法难以治疗或疗效不佳的疾病提供了一种新的治疗途径,在近20年里获得了突飞猛进的发展,应用范围不断拓宽,被广大患者所接受。但作为一种侵入性操作,增加了医院感染的可能。为了预防和控制介入导管相关血流感染的发生,我们在实际工作中采取了一系列措施,至今没有1例相关事件发生。现将我们的经验介绍如下。