Intravascular Catheters and Biofilm Control

Intravascular catheters are the most common cause of nosocomially acquired bloodstream infections. Bacteria found adhering to the intraluminal surfaces of catheters are the principal source and cause of these infections. Adherent bacteria overtime are known to form multicellular communities which become encased within a three dimensional matrix of extracellular polymeric material known as biofilms, which are thought to be responsible for persistent infections. Consequently, a number of technologies have been developed to help prevent and control biofilms in intravascular catheters. One such approach involves impregnating catheter material with antimicrobial agents. Unfortunately these methods are not universally effective in preventing catheter-related biofilm infections. Technologies that utilise antimicrobials, as catheter locks have been shown to have more potential for preventing biofilm formation and reducing the incidences of catheter related bloodstream infections (CRBSI). This article discusses the significance of biofilms in intravascular catheters and determines whether the treatments available today are proving to be effective for controlling biofilms and draws attention to future avenues which are being investigated to control biofilms and therefore CRBSI.

Guideline for Prevention of Intravascular-Device–Related Infections

The “Guideline for Prevention of Intravascular Device-Related Infections” is designed to reduce the incidence of intravascular device-related infections by providing an over view of the evidence for recommendations considered prudent by consensus of Hospital Infection Control Practices Advisor y Committee (HICPAC) members. This two-part document updates and replaces the previously published Centers for Disease Control's (CDC) Guideline for Intravascular Infections (Am J Infect Control1983;11:183-199). Part I, “Intravascular Device-Related Infections: An Over view” discusses many of the issues and controversies in intravascular-device use and maintenance. These issues include definitions and diagnosis of catheter-related infection, appropriate barrier precautions during catheter insertion, inter vals for replacement of catheters, intravenous (IV) fluids and administration sets, catheter-site care, the role of specialized IV personnel, and the use of prophylactic antimi-crobials, flush solutions, and anticoagulants. Part II, “Recommendations for Prevention of Intravascular Device-Related Infections” provides consensus recommendations of the HICPAC for the prevention and control of intravascular device-related infections. A working draft of this document also was reviewed by experts in hospital infection control, internal medicine, pediatrics, and intravenous therapy. However, all recommendations contained in the guideline may not reflect the opinion of all reviewers.

Infection control in the intensive care unit

It is critical for health care personnel to recognize and appreciate the detrimental impact of intensive care unit (ICU)-acquired infections. The economic, clinical, and social expenses to patients and hospitals are overwhelming. To limit the incidence of ICU-acquired infections, aggressive infection control measures must be implemented and enforced. Researchers and national committees have developed and continue to develop evidence-based guidelines to control ICU infections. A multifaceted approach, including infection prevention committees, antimicrobial stewardship programs, daily reassessments-intervention bundles, identifying and minimizing risk factors, and continuing staff education programs, is essential. Infection control in the ICU is an evolving area of critical care research.

Needleless closed system does not reduce central venous catheter-related bloodstream infection: a retrospective study

The needleless closed system (NCS) has been disseminated in several clinical fields to prevent central venous catheter-related bloodstream infection (CVC-RBSI), in place of the conventional Luer cap system (LCS). The purpose of this study is to examine whether NCS is really superior to conventional LCS for prevention of CVC-RBSI. Between May 2002 and December 2008, 1767 patients received CVC in our department. The time interval from insertion to development of CVC-RBSI was compared retrospectively between selected patients who were treated using the conventional LCS (group 1, n = 89, before June 2006) and the NCS (group 2, n = 406, June 2006 and after). Kaplan-Meier analysis revealed no significant difference in the time interval from insertion to development of CVC-RBSI between the two groups. NCS does not reduce CVC-RBSI in adult colorectal cancer patients who undergo CVC insertion.

Clinical guidelines on central venous catheterisation. Swedish Society of Anaesthesiology and Intensive Care Medicine

Safe and reliable venous access is mandatory in modern health care, but central venous catheters (CVCs) are associated with significant morbidity and mortality, This paper describes current Swedish guidelines for clinical management of CVCs The guidelines supply updated recommendations that may be useful in other countries as well. Literature retrieval in the Cochrane and Pubmed databases, of papers written in English or Swedish and pertaining to CVC management, was done by members of a task force of the Swedish Society of Anaesthesiology and Intensive Care Medicine. Consensus meetings were held throughout the review process to allow all parts of the guidelines to be embraced by all contributors. All of the content was carefully scored according to criteria by the Oxford Centre for Evidence-Based Medicine. We aimed at producing useful and reliable guidelines on bleeding diathesis, vascular approach, ultrasonic guidance, catheter tip positioning, prevention and management of associated trauma and infection, and specific training and follow-up. A structured patient history focused on bleeding should be taken prior to insertion of a CVCs. The right internal jugular vein should primarily be chosen for insertion of a wide-bore CVC. Catheter tip positioning in the right atrium or lower third of the superior caval vein should be verified for long-term use. Ultrasonic guidance should be used for catheterisation by the internal jugular or femoral veins and may also be used for insertion via the subclavian veins or the veins of the upper limb. The operator inserting a CVC should wear cap, mask, and sterile gown and gloves. For long-term intravenous access, tunnelled CVC or subcutaneous venous ports are preferred. Intravenous position of the catheter tip should be verified by clinical or radiological methods after insertion and before each use. Simulator-assisted training of CVC insertion should precede bedside training in patients. Units inserting and managing CVC should have quality assertion programmes for implementation and follow-up of routines, teaching, training and clinical outcome. Clinical guidelines on a wide range of relevant topics have been introduced, based on extensive literature retrieval, to facilitate effective and safe management of CVCs.

Right internal jugular vein is recommended for central venous catheterization

BACKGROUND

The internal jugular vein (IJV) is one of the recommended sites for safe insertion of a central venous catheter (CVC). Although CVC insertion via the IJV has a lower risk of severe complications such as pneumothorax and arterial bleeding than insertion via the subclavian vein, few reports have provided concrete evidence for the safety of a right-sided approach.

PURPOSE

To examine whether a right-sided approach, rather than a left-sided one is superior for CVC insertion via the IJV.

METHODS

A retrospective study was performed to compare the right IJV with the left in terms of characteristics such as vertical and horizontal diameters, depth from the skin, and the relationship between the IJV and the common carotid artery (CCA) using the same computed tomography axial slice.

RESULTS

From April 2006 to September 2008, 100 patients (50 male and 50 female) who underwent CVC insertion via the IJV before surgery for colorectal cancer were enrolled. Vertical and horizontal diameters of the right IJV were significantly larger than those of the left IJV [right: left (cm), 1.51 +/- 0.41 vs 1.13 +/- 0.34, p <.0001, 1.54 +/- 0.36 vs 1.08 +/- 0.33, p <.0001], respectively. The right IJV runs more superficially than the left IJV [right: left (cm), 1.74 +/- 0.60 vs 1.87 +/- 0.56, p <.0001].

CONCLUSIONS

Because the right IJV has a much wider diameter and runs more superficially than the left IJV, a right-sided approach is more acceptable than a left-sided one for CVC insertion via the IJV.

Catheter-Related Bloodstream Infection in the Intensive Care Unit

Catheter-related bloodstream infection (CRBSI) is a significant cause of morbidity and mortality in the intensive care unit, contributing to prolonged stay with the associated cost and resource implications. Various mechanisms of infection have been suggested, and consequently, numerous interventions to reduce the burden of infection have been proposed, the efficacy of most of which remains controversial. The practice of routine catheter change and preferential use of the subclavian vein insertion site are both associated with an increased risk of mechanical complications, which may outweigh any potential benefit. Additionally, the use of silver- and antiseptic-impregnated catheters, of questionable benefit in the ICU patient population, is also argued to be unjustified in terms of efficacy and cost.

A small scale study in a London university district general hospital ICU found that while infection rates were low, the majority of infections were caused by Staphylococcus epidermidis and thus were probably a result of contamination either from the patient's commensal flora or acquired by contamination from healthcare workers. In accordance with published findings, this suggests that preventing contamination will decrease infection rates. Strict aseptic technique and the use of sterile fields during insertion are most likely the main contributors in reducing rates of infection. This together with education of staff across disciplines and adherence to local guidelines are likely to be the mainstays of reducing CRBSI in the ICU.

Tunnelled Catheters for the Haemodialysis Patient

Haemodialysis depends upon the establishment of a durable means of vascular access. Although the creation of a successful arterio-venous Fistulae (AVF) is the ideal, this is not always possible or practical. Tunnelled catheters play an important role as an interim/bridge technique for emergency access or while an AVF matures, but may be associated with significant morbidity. The aim of this review is to highlight recent evidence based developments in tunnelled catheters, including methods of placement, complications and possible management strategies.

Catheter-Related Bloodstream Infections in the Intensive Care Unit Population

Catheter-related bloodstream infections (CRBIs) are a cause of significant morbidity and mortality in intensive care unit patients. Development of CRBIs may occur by several mechanisms. The role of fibrin and biofilm development and their impact on therapy are described. Multiple preventative strategies related to the insertion and maintenance of the catheter site have been identified. Topical antisepsis and use of antibiotic-impregnated catheters are also beneficial for reducing the incidence of CRBI. Antibiotic lock solutionsmay be effective in preventing CRBI for select patients with longterm catheter use. Treatment of CRBIs should be based on suspected organisms, whichmost commonly include staphylococci, gram-negatives, including Pseudomonas aeruginosa andCandida species. Duration of treatment and decisions regarding catheter removal are controversial. Evaluation and treatment of potential complications of CRBIs, including endocarditis, infected thrombophlebitis, osteomyelitis, and endophthalmitis, are essential.

Strict infection control measures do not prevent clonal spread of coagulase negative staphylococci colonizing central venous catheters in neutropenic hemato-oncologic patients

Coagulase negative staphylococci (CoNS) are a main cause of catheter related infections (CRI). Earlier studies (1994-1996) revealed a high incidence of CRI (6 per 1000 catheter days) among neutropenic hemato-oncologic patients in the Erasmus MC Hematology Department (Rotterdam, The Netherlands). This was mainly explained by expansion of two methicillin resistant Staphylococcus epidermidis (MRSE) clones (Nouwen et al., J. Clin. Microbiol. 36 (1998) 2696-2702). In a new, 16-bed unit in the same institution, we investigated the effect of strict clinical isolation measures on the incidence of CRI. During two 6-month screening periods (period I: April 1998-December 1998 and period II: April 1999-October 1999) all patients receiving a central venous catheter were prospectively monitored for the development of CRI. During period I every visitor of the cubicles had to wear hair caps, masks, gowns and gloves. During period II these procedures were abolished, but hands were cleansed using alcohol and masks were worn during both periods in case of coughing and sneezing. All CoNS strains isolated from blood cultures were genetically classifies by pulsed field gel electrophoresis (PFGE). The incidence of CRI during period I was 13.0 per 1000 catheter days, in comparison to 9.6 in period II (P=0.84). During this latter period, 19 CRI were diagnosed, 14 catheter related bacteremia episodes (CRB) and five local infections. Seventy-two percent (n=9) of CRB were due to a CoNS. The mean catheter survival until appearance of a CRI increased from 43 days during period I to 78 days in period II (P=0.39). The mean catheter survival until infection related removal was increased from 43 days to 133 days (P=0.12). During period I less experienced intervention radiologists introduced the catheters, which may have limited the efficacy of the strict hygiene measures. Thus, abolishing strict isolation precautions had no negative effect on the incidence of CRI. After genotyping of 38 MRSE strains isolated from blood and central venous catheter cultures of 12 patients in period II, eight PFGE types were found. Three types were found in more than one patient, but based on epidemiological data patient-to-patient spread could not be proven. No genotypic identity between patient and personnel CoNS isolates was shown and the two major clonal types that were present between 1994 and 1996 were not encountered. However, from December 1998 onwards new MRSE clones could be identified (types E and J). In conclusion, despite a constant rate of CRI and implementation of optimal patient care, clonal spread of MRSE strains was not prevented by strict hygiene measures.

Epidural catheter infections

Epidural analgesia is used as a method of pain relief throughout the UK. It is used short-term in obstetric practice, following surgery and after trauma, and also longer-term for malignancy and chronic pain. Infection may occur as a complication of the technique. Both deep infection, e.g., meningitis, paraspinal and epidural abscesses, and superficial skin infections can occur. To minimize infection risk, epidural catheters should be inserted using an aseptic technique and subsequently checked at least daily, looking for evidence of superficial and deep infection. There should be a dedicated pain team to ensure that education of staff occurs and to carry out regular audits of the service.

Can we achieve consensus on central venous catheter-related infections?

Central venous catheter-related bacteraemia is a substantial and preventable source of iatrogenic morbidity and mortality. A single episode of catheter-related bacteraemia has an estimated cost of A$50,000, with an attributable mortality between 10 and 35%. Catheter colonization is diagnosed with standard culture techniques. Diagnostic criteria for catheter-related bacteraemia include the results of cultures from the catheter tip, the peripheral blood and other possible sites of infection. The presence of clinical symptoms and subsequent defervescence may assist in making the diagnosis. This review explores the existing definitions of catheter-related infections and proposes a new and more rigorous classification with criteria for definite, probable and possible catheter-related bacteraemia. The authors hope that this classification will enhance the interpretation of the literature and the planning of new investigations. Infection rates can be reduced by appropriate site selection, adequate skin preparation, sterile technique and appropriate dressings. Decreased manipulation of administration sets, with more careful technique and less frequent set replacement, may reduce hub contamination. Infection rates increase with the duration in situ of the catheter, however are not reduced by regular scheduled catheter replacement or guide-wire exchanges. A range of antimicrobial catheter materials and coatings are under investigation, some of which are effective in reducing the rate of catheter-related bacteraemia. Chorhexidine-silver sulphadiazine and rifampicin-minocycline are the best studied combinations to date. Further developments are expected, although none are likely to be as effective as not inserting or removing the central venous catheter when it is not required.

Decreasing catheter colonization through the use of an antiseptic-impregnated catheter: a continuous quality improvement project

STUDY OBJECTIVES

To evaluate the use of an antiseptic-impregnated (chlorhexidine and silver sulfadiazine) catheter for the prevention of catheter colonization and catheter-related bloodstream infection (CR-BSI). Then, based on these findings, to implement changes in hospital policy and to assess their effect on a hospital service.

DESIGN

Prospective, randomized, controlled (phase I); prospective, concurrent data collection (phase II).

SETTING

Tertiary referral hospital with level 1 trauma center.

PATIENTS

Patients > 12 years of age with central venous catheters placed while they were in the emergency room, neurotrauma ICU, or medical/surgical ICU from May through December, 1995 (phase I). All patients > 12 years of age on the trauma service admitted from November 16, 1996, through November 15, 1997 (phase II).

INTERVENTIONS

Randomization table determined whether the patient would receive an antiseptic-impregnated catheter (AIC) or nonimpregnated catheter (NIC) (phase I). All removed or exchanged catheters were sent for semiquantitative culture. In phase II, only AICs were used; "length of time" and "fever" were discouraged as reasons for catheter exchange or removal; and only the tip was sent for culture.

MEASUREMENTS AND RESULTS

In phase I, there were 139 catheters placed in 60 patients in the NIC group and 98 catheters placed in 55 patients in the AIC group. Two catheters (2.0/100 catheters) in the AIC group were found to be colonized, compared with 25 (18.0/100 catheters) in the NIC group (p = 0.001). The catheter colonization rates were 2.27/1,000 catheter days (AIC) and 24.68/1,000 catheter days (NIC) (p < 0.001), while the CR-BSI rates were 1.14/1,000 catheter days (AIC) and 3.9.5/1,000 catheter days (NIC) (p = 0.31). The reason for each catheter removal/exchange was noted, and only "positive blood culture" was statistically significant overall. The tip segment was found to be positive more often than the intracutaneous segment. In phase II, there were 213 AICs placed in 101 patients. The colonization rate was 3.8/100 catheters (4.52/1,000 catheter days), and CR-BSI rate was 1.0/100 catheters (0.6/1,000 catheter days). The colonization rate for catheters left in place remained low for catheters left in place < 14 days (1.6/100 catheters). Only 11% of catheters were exchanged/removed for reason of "fever," as compared with 23% in phase I.

CONCLUSIONS

AICs significantly reduce the rate of central venous catheter colonization. In addition, the apparent protective effects of the catheter over time permit less frequent exchanges or removals of the catheters, decreasing both patient risk and hospital cost.

Hickman catheter-related infections in neutropenic patients: insertion in the operating theater versus insertion in the radiology suite

PURPOSE

To determine the influence of microbial air quality during Hickman catheter insertion in the operating theater versus insertion in the radiology suite on the incidence of catheter-related infections (CRIs).

PATIENTS AND METHODS

Hemato-oncologic patients with prolonged neutropenia on antimicrobial prophylaxis were entered onto the study. Catheters were inserted by experienced radiologists under sonographic and fluoroscopic guidance.

RESULTS

Forty-eight Hickman catheters in 39 patients were inserted (23 in the operating theater, 25 in the radiology suite). CRIs were seen in 16 catheters (33%; six per 1,000 catheter days; eight in each group). Local infections were found in nine catheters (22%; six in the operating theater v three in the radiology suite; not significant [NS]), catheter-related bacteremia was found in 10 (29%; three in the operating theater v seven in the radiology suite; NS). Coagulase-negative staphylococci (CoNS) caused all CRIs. Despite early vancomycin therapy, 11 (69%; four in the operating room group v seven in the radiology suite group; NS) of the catheters with CRIs had to be removed prematurely. At 90 days after insertion, catheter survival was 78% and 60% (NS) for the operating room and radiology suite, respectively. Multivariate analysis showed that neutropenia increased the CRI risk 20-fold (P =.004) and was strongly related to premature catheter removal owing to infection (relative risk = 11.9; P =.009). Neutropenia on the day of insertion was also significantly correlated with CRI (P =.04) and premature catheter removal owing to infection (P =.03). Serial cultures of blood, exit site, and catheter hub did not predict the development of CRI.

CONCLUSION

The high incidence of Hickman CRI caused by CoNS was not associated with insertion location (operating theater v radiology suite). Neutropenia, including neutropenia on the day of insertion, was a significant risk factor for CRI and infection-related catheter removal.

Concomitant factors of decompensation in chronic heart failure

The concomitant factors implicated in 328 nonfatal decompensations of 304 patients with congestive heart failure were: arrhythmias in 24%, infections in 23%, poor compliance in 15%, angina in 14%, iatrogenic factors in 10%, and other causes in 5% of cases. New York Heart Association class and right atrial pressure significantly related to the occurrence of decompensation. Poor compliance and angina were unpredictable, infection was related to pulmonary wedge pressure, iatrogenic factors were predicted by the more advanced functional classes, whereas arrhythmias were more frequent in patients with renal failure.