Bacteraemia related to indwelling central venous catheters: prevention, diagnosis and treatment

Comparison of Infection Rates between Single-Lumen and Double-Lumen Chest Ports among Patients with Cancer: A Propensity Score Matching Analysis

PURPOSE

To compare the port infection rate between single-lumen (SL) and double-lumen (DL) ports and to determine whether the use of a DL port is an independent risk factor for port infection among patients with cancer.

MATERIALS AND METHODS

This retrospective study included 2,573 adult oncologic patients (aged >18 years) who had either a SL (n = 841) or a DL (n = 1,732) chest port implanted between 2013 and 2020 at a single institution. Patients who had port infection, including port-site infection and port-related bloodstream infection, were identified through chart review. After propensity score matching based on 13 potentially confounding variables, a total of 493 pairs of patients with either SL (SL group) or DL (DL group) ports were subjected to analysis. The port infection rate was compared between the 2 groups using Poisson regression. Multivariate proportional subdistribution hazards regression (PSHREG) analysis was conducted to determine whether use of a DL port is an independent risk factor for port infection.

RESULTS

The cumulative follow-up period for the matched cohort was 371,853 catheter-days (median, 297 catheter-days per port; range, 0-1,903 catheter-days). The port infection rate of the DL group was significantly higher than that of the SL group (0.232 vs 0.113 infections per 1,000 catheter-days; P = .001). PSHREG analysis demonstrated that use of a DL port was an independent risk factor of port infection (subdistribution hazard ratio, 2.30; 95% CI, 1.33-3.78; P = .002).

CONCLUSIONS

DL ports were associated with a higher risk of port infection compared with SL ports in adult oncologic patients.

Outcomes of Pediatric Central Venous Access Device Placement With Concomitant Surgical Procedures

BACKGROUND

Children frequently undergo placement of a tunneled central venous catheter or port (CVAD) concomitantly with other surgical procedures (CVAD-CP), but the risk factors for early CVAD complications with this practice are unclear.

METHODS

Children undergoing CVAD-CP were identified from the National Surgical Quality Improvement Program-Pediatric 2012-2016 database. Predictor variables included demographics, CP characteristics, malignancy, and CVAD type. Outcome variables were CVAD-associated bloodstream infection (CLABSI) or new deep venous thrombosis (nDVT) within 30 d. Patients with and without CLABSI or nDVT were compared, and the temporal relationship of nDVT and CLABSI was investigated. Multivariable logistic regression modeling was used to assess independent risk factors for CLABSI.

RESULTS

Of 2036 patients included, median age was 1.5 y, 35% had malignancy, and 40% had a clean concomitant procedure. Overall, 1.3% developed CLABSI and 0.7% developed nDVT. Multivariable regression modeling revealed higher risk of CLABSI with clean CPs (odds ratio [OR] 2.4, 95% confidence interval [CI] 1.06-5.34, P = 0.035), tunneled catheters (OR 3.2, 95% CI 1.18-8.56, P = 0.022), and longer anesthesia duration (OR 1.02 per 10 min, 95% CI 1.00-1.04, P = 0.042). nDVT was strongly associated with CLABSI (21% CLABSI among those with DVT, 0.5% among those without, P ≤ 0.0001). In all cases of nDVT with CLABSI, the diagnosis of DVT preceded diagnosis of CLABSI, by a median of 7 d.

CONCLUSIONS

The type of CVAD and characteristics of the concomitant procedure influence early CLABSI after CVAD-CP. The unexpected finding of higher CLABSI rates among clean concomitant procedures suggests that perioperative prophylactic antibiotics should not be withheld in this setting, but requires prospective validation. nDVT is frequently diagnosed prior to CLABSI, suggesting a possible role for antibiotics in the treatment of postoperative DVT after CVAD placement.

Evaluation of the placement and maintenance of central venous jugular catheters in critically ill dogs and cats

OBJECTIVE

To describe problems noted during central venous jugular catheter (CVJC) placement, conditions associated with unsuccessful catheterization, and CVJC maintenance complications.

DESIGN

Prospective observational study from September 2014 to September 2015.

SETTING

University veterinary teaching hospital.

ANIMALS

Twenty-seven dogs and 20 cats hospitalized in a veterinary ICU. Patients were excluded if previously hospitalized with a CVJC or lacked sufficient data.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Ninety-one percent of indwelling CVJCs were placed successfully (43/47, 95% CI: 80%, 98%). Procedural-related difficulties that resulted in the inability to place a CVJC totaled 18/63 (28.6%, 95% CI: 18%, 41%) and included the inability to puncture the vessel (10), hematoma (6), malposition (1), and dislodgement (1). Procedural complications occurred in 24/47 patients (51%, 95% CI: 36%, 66%) and included cardiac dysrhythmias (13), hematoma (6), CVJC placement failure (4), and malposition (1). Risk factors associated with multiple catheterization attempts included increased age (7.5 years [± 4.2] vs 10.6 years [± 4.1], P = 0.04), smaller size (8.0 kg [0.6-51.9 kg] vs 4.4 kg [2.6-6.8 kg], P < 0.01) and thinner body condition score (median 5/9 [2/9-9/9] vs 4/9 [2/9-7/9], P = 0.04). The risk factor associated with dysrhythmias was smaller patient size (6.8 kg [2.6-51.9 kg] vs 4.8 kg [0.6-29.5 kg], P = 0.04). Eighteen indwelling complications occurred in 14 patients and included mechanical obstruction (7), skin irritation (6), malposition (4), and inflammation (1). Risk factors for indwelling complications included longer dwell time (5 days [2-30] vs 3 days [1-10], P < 0.01) and the administration of an irritant medication (P = 0.02).

CONCLUSIONS

Complications were documented in the placement and maintenance of CVJCs in critically ill patients with a low incidence of life-threatening sequelae. Risk factors associated with both unsuccessful CVJC placement and indwelling CVJC complications were identified.

Comparison of a silver-coated needleless connector and a standard needleless connector for the prevention of central line-associated bloodstream infections

OBJECTIVE

To assess the impact of a novel, silver-coated needleless connectors (NCs) on central-line-associated bloodstream infection (CLABSI) rates compared with a mechanically identical NCs without a silver coating.

DESIGN

Prospective longitudinal observation study SETTING Two 500-bed university hospitals

PATIENTS

All hospitalized adults from November 2009 to June 2011 with non-hemodialysis central lines

INTERVENTIONS

Hospital A started with silver-coated NCs and switched to standard NCs in September 2010; hospital B started with standard NCs and switched to silver-coated NCs. The primary outcome was the difference revealed by Poisson multivariate regression in CLABSI rate using standard Centers for Disease Control and Prevention surveillance definitions. The secondary outcome was a comparison of organism-specific CLABSI rates by NC type.

RESULTS

Among 15,845 hospital admissions, 140,186 central-line days and 221 CLABSIs were recorded during the study period. In a multivariate model, the CLABSI rate per 1,000 central-line days was lower with silver-coated NCs than with standard NCs (1.21 vs 1.79; incidence rate ratio=0.68 [95% CI: 0.52-0.89], P=.005). A lower CLABSI rate per 1,000 central-line days for the silver-coated NCs versus the standard NCs was observed with S. aureus (0.11 vs 0.30, P=.02), enterococci (0.10 vs 0.27, P=.03), and Gram-negative organisms (0.28 vs 0.63, P=.003) but not with coagulase-negative staphylococci (0.31 vs 0.36) or Candida spp. (0.42 vs 0.40).

CONCLUSIONS

The use of silver-coated NCs decreased the CLABSI rate by 32%. CLABSI reduction efforts should include efforts to minimize contamination of NCs.

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.

epic3: national evidence-based guidelines for preventing healthcare-associated infections in NHS hospitals in England

National evidence-based guidelines for preventing healthcare-associated infections (HCAI) in National Health Service (NHS) hospitals in England were originally commissioned by the Department of Health and developed during 1998-2000 by a nurse-led multi-professional team of researchers and specialist clinicians. Following extensive consultation, they were first published in January 2001(1) and updated in 2007.(2) A cardinal feature of evidence-based guidelines is that they are subject to timely review in order that new research evidence and technological advances can be identified, appraised and, if shown to be effective for the prevention of HCAI, incorporated into amended guidelines. Periodically updating the evidence base and guideline recommendations is essential in order to maintain their validity and authority. The Department of Health commissioned a review of new evidence and we have updated the evidence base for making infection prevention and control recommendations. A critical assessment of the updated evidence indicated that the epic2 guidelines published in 2007 remain robust, relevant and appropriate, but some guideline recommendations required adjustments to enhance clarity and a number of new recommendations were required. These have been clearly identified in the text. In addition, the synopses of evidence underpinning the guideline recommendations have been updated. These guidelines (epic3) provide comprehensive recommendations for preventing HCAI in hospital and other acute care settings based on the best currently available evidence. National evidence-based guidelines are broad principles of best practice that need to be integrated into local practice guidelines and audited to reduce variation in practice and maintain patient safety. Clinically effective infection prevention and control practice is an essential feature of patient protection. By incorporating these guidelines into routine daily clinical practice, patient safety can be enhanced and the risk of patients acquiring an infection during episodes of health care in NHS hospitals in England can be minimised.

Drug susceptibility and clonality of methicillin-resistant Staphylococcus epidermidis in hospitalized patients with hematological malignancies

PURPOSE

To evaluate the clonal relatedness and drug susceptibility of Streptococcus epidermidis isolated from hematological patients.

METHODS

All S. epidermidis isolated from hematological patients who developed bloodstream infections between June 2005 and December 2007 were included. The clonal relationship was tested by means of pulsed-field gel electrophoresis (PFGE) analysis.

RESULTS

Fifteen methicillin-resistant S. epidermidis (MRSE) isolates were examined from patients' blood culture samples. Two subgroups that differed approximately by 40% in their PFGE banding were identified. In clinical practice, two cases were cured with cephalosporin only, thus demonstrating sensitivity of the strains to beta-lactam antibiotics.

CONCLUSIONS

Our results represent two significant findings. One is the major capability of MRSE to colonize patients. The other is that some MRSE isolates proved to be sensitive to clindamycin, minocycline, and cephalosporin, so that using antibiotics to which MRSE is sensitive as first-line therapy can avoid the need for vancomycin in clinical settings.

epic2: National evidence-based guidelines for preventing healthcare-associated infections in NHS hospitals in England

National evidence-based guidelines for preventing healthcare-associated infections (HCAI) in National Health Service (NHS) hospitals in England were commissioned by the Department of Health (DH) and developed during 1998-2000 by a nurse-led multi-professional team of researchers and specialist clinicians. Following extensive consultation, they were published in January 2001. These guidelines describe the precautions healthcare workers should take in three areas: standard principles for preventing HCAI, which include hospital environmental hygiene, hand hygiene, the use of personal protective equipment, and the safe use and disposal of sharps; preventing infections associated with the use of short-term indwelling urethral catheters; and preventing infections associated with central venous catheters. The evidence for these guidelines was identified by multiple systematic reviews of experimental and non-experimental research and expert opinion as reflected in systematically identified professional, national and international guidelines, which were formally assessed by a validated appraisal process. In 2003, we developed complementary national guidelines for preventing HCAI in primary and community care on behalf of the National Collaborating Centre for Nursing and Supportive Care (National Institute for Healthand Clinical Excellence). A cardinal feature of evidence-based guidelines is that they are subject to timely review in order that new research evidence and technological advances can be identified, appraised and, if shown to be effective in preventing HCAI, incorporated into amended guidelines. Periodically updating the evidence base and guideline recommendations is essential in order to maintain their validity and authority. Consequently, the DH commissioned a review of new evidence published following the last systematic reviews. We have now updated the evidence base for making infection prevention and control recommendations. A critical assessment of the updated evidence indicated that the original epic guidelines published in 2001 remain robust, relevant and appropriate but that adjustments need to be made to some guideline recommendations following a synopsis of the evidence underpinning the guidelines. These updated national guidelines (epic2) provide comprehensive recommendations for preventing HCAI in hospitals and other acute care settings based on the best currently available evidence. Because this is not always the best possible evidence, we have included a suggested agenda for further research in each section of the guidelines. National evidence-based guidelines are broad principles of best practice which need to be integrated into local practice guidelines. To monitor implementation, we have suggested key audit criteria for each section of recommendations. Clinically effective infection prevention and control practice is an essential feature of protecting patients. By incorporating these guidelines into routine daily clinical practice, patient safety can be enhanced and the risk of patients acquiring an infection during episodes of healthcare in NHS hospitals in England can be minimised.

Diagnosis of central venous catheter related infection in adult patients

Intravascular catheters are one of the main causes of bacteraemia and septicaemia in hospitalised patients and continue to be associated with a significant morbidity and mortality. Two main types of infections occur, they can be either localised at the catheter insertion site of systemic with a septicaemia. The clinical parameters related to these infections are presented. The laboratory diagnosis of these infections is also extensively reviewed and recommendations are made as to the most appropriate diagnostic method to be used.

Chlorhexidine and silver-sulfadiazine coated central venous catheters in haematological patients--a double-blind, randomised, prospective, controlled trial

BACKGROUND

Central venous catheters (CVCs) are essential for the intensive care of patients with haematological illness. Catheter-related infections (CRI) are an important problem in modern medicine, which may lead to life-threatening situations, to prolonged hospitalisation and increased cost. In immunocompromised patients suffering from haemato-oncological diseases, CRI is a significant factor for adverse outcome. Several clinical studies have shown that CVCs coated with antiseptics such as chlorhexidine and silver-sulfadiazine (CHSS) reduce the risk of catheter-related bacteraemia. Most studies, however, were performed on intensive care patients not suffering from chemotherapy-induced immunosuppression.

PATIENTS AND METHODS

A prospective double-blind, randomised, controlled trial was performed to investigate the effectiveness of CHSS-coated catheters in haemato-oncological patients. A total number of 184 catheters (median duration of placement, 11 days) were inserted into 184 patients (male 115, female 69), of which 90 were antiseptically coated. After removal, all catheters were investigated for bacterial growth.

MAIN RESULTS

Catheters coated with CHSS were effective in reducing the rate of significant bacterial growth on either the tip or subcutaneous segment (26%) compared to control catheters (49%). The incidence of catheter colonisation was also significantly reduced (12% coated vs 33% uncoated). Data obtained show a significant reduction of catheter colonisation in CHSS catheters. There was no significant difference in the incidence of catheter-related bacteraemia (3% coated vs 7% uncoated). However, due to the overall low rate of CRI, we could not observe a significant reduction in the incidence of catheter-related bacteraemia.

CONCLUSION

Our data show that the use of CHSS catheters in patients with haematological malignancy reduces the overall risk of catheter colonisation and CRI, although the incidence of catheter-related bacteremia was similar in both groups.

Infection control issues in central venous catheter care

Central venous catheters (CVCs) are now a routine part of patient management in the intensive care unit (ICU). Over time, a vast amount of literature associated with the use and care of CVCs has accumulated. The purpose of this article is to discuss the literature associated with the care of these devices in a narrative format. Although particular attention is paid to infection control issues, other fundamental areas such as catheter design, dressings, line changing and post insertion management are also discussed. The article goes on to look at the future of CVC design and concludes with an analysis of future developments related to CVCs.

Diagnosis of infection in sepsis: An evidence-based review

OBJECTIVE

In 2003, critical care and infectious disease experts representing 11 international organizations developed management guidelines for the diagnosis of infection in sepsis that would be of practical use for the bedside clinician, under the auspices of the Surviving Sepsis Campaign, an international effort to increase awareness and improve outcome in severe sepsis.

DESIGN

The process included a modified Delphi method, a consensus conference, several subsequent smaller meetings of subgroups and key individuals, teleconferences, and electronic-based discussion among subgroups and among the entire committee.

METHODS

The modified Delphi methodology used for grading recommendations built on a 2001 publication sponsored by the International Sepsis Forum. We undertook a systematic review of the literature graded along five levels to create recommendation grades from A to E, with A being the highest grade. Pediatric considerations to contrast adult and pediatric management are in the article by Parker et al. on p. S591.

CONCLUSIONS

Obtaining a precise bacteriological diagnosis before starting antibiotic therapy is, when possible, of paramount importance for the success of therapeutic strategy during sepsis. Two to three blood cultures should be performed, preferably from a peripheral vein, without interval between samples to avoid delaying therapy. A quantitative approach is preferred in most cases when possible, in particular for catheter-related infections and ventilator-associated pneumonia. Diagnosing community-acquired pneumonia is complex, and a diagnostic algorithm is proposed. Appropriate samples are indicated during soft tissue and intraabdominal infections, but cultures obtained through the drains are discouraged.

A review of risk factors for catheter-related bloodstream infection caused by percutaneously inserted, noncuffed central venous catheters: implications for preventive strategies

Strategies for preventing central venous catheter (CVC)-related bloodstream infection are most likely to be effective if guided by an understanding of the risk factors associated with these infections. In this critical review of published studies of risk factors for CVC-related bloodstream infection that were prospective and used multivariable techniques of data analysis or that were randomized trials of a preventive measure, a significantly increased risk of catheter-related bloodstream infection was associated with inexperience of the operator and nurse-to-patient ratio in the intensive care unit, catheter insertion with less than maximal sterile barriers, placement of a CVC in the internal jugular or femoral vein rather than subclavian vein, placement in an old site by guidewire exchange, heavy colonization of the insertion site or contamination of a catheter hub, and duration of CVC placement > 7 days. Prospective studies or randomized trials of control measures focusing on these risk factors have been shown to reduce risk significantly: formal training in CVC insertion and care, use of maximal sterile barriers at insertion, use of chlorhexidine rather than povidone-iodine for cutaneous antisepsis, applying a topical anti-infective cream or ointment or a chlorhexidine-impregnated dressing to the insertion site, and the use of novel catheters with an anti-infective surface or a contamination resistant hub. Better prospective studies of sufficient size to address all potential risk factors, including insertion site and hub colonization, insertion technique, and details of follow-up care, would enhance our understanding of the pathogenesis of CVC-related bloodstream infection and guide efforts to develop more effective strategies for prevention.

The promise of novel technology for the prevention of intravascular device-related bloodstream infection. II. Long-term devices

Intravascular devices (IVDs) are widely used for vascular access but are associated with a substantial risk of IVD-related bloodstream infection (BSI). The development of novel technologies based on our understanding of pathogenesis promises a quantum reduction in IVD-related infections in an era of growing nursing shortage. Infections of long-term IVDs (most are in place for > or =10 days), including cuffed and tunneled central venous catheters (CVCs), implanted subcutaneous central venous ports, and peripherally inserted central catheters (PICCs), are primarily due to microorganisms that gain access to the catheter hub and lumen. Novel securement devices and antibiotic lock solutions have been shown to reduce the risk of IVD-related BSI in prospective randomized trials. The challenge for the future will be to identify new preventative technologies and to begin to more-widely adapt those technologies that have already been shown to be efficacious and cost effective.

The promise of novel technology for the prevention of intravascular device-related bloodstream infection. I. Pathogenesis and short-term devices

Intravascular devices (IVDs) are widely used for vascular access but are associated with substantial risk of development of IVD-related bloodstream infection (BSI). The development of novel technologies, which are based on an understanding of pathogenesis, promises a quantum reduction in IVD-related infections in an era of growing nursing shortages. Infections of short-term IVDs (that is, those in place <10 days), including peripheral venous catheters, noncuffed and nontunneled central venous catheters (CVCs), and arterial catheters, derive mainly from microorganisms colonizing the skin around the insertion site, which most often gain access extraluminally. More-effective cutaneous antiseptics, such as chlorhexidine, a chlorhexidine-impregnated sponge dressing, CVCs with an anti-infective coating, anti-infective CVC hubs, and novel needleless connectors, have all been shown to reduce the risk of IVD-related BSI in prospective randomized trials. The challenge for the future will be to identify new preventative technologies and to begin to adapt more widely those technologies already shown to be efficacious and cost-effective.

The Role of Intravascular Devices in Sepsis

Intravascular devices (IVDs) are widely used in modern day health care. Unfortunately, their use is associated with substantial risk of bloodstream infection (BSI) and sepsis, with increased hospitalization and hospital mortality. IVDs are the most common cause of nosocomial BSI. The wider use of new methodologies for diagnosis of IVD-related infection should allow earlier and more focused therapy and, especially, improve the accuracy of surveillance. Of all nosocomial infections, IVD-related BSIs are most amendable to prevention.

Nosocomial Infections in the Intensive Care Unit Associated with Invasive Medical Devices

Modern day health care has become synonymous with cutting-edge, high-tech medicine, which includes a large and growing number of invasive medical devices, especially in intensive care units. The most widely used of these devices--intravascular catheters of many types and urinary catheters--account for more than one half of all institutionally acquired infections. Growing knowledge of the pathogenesis and epidemiology of these infections has given birth to novel and more effective control measures, the most promising of which are technologically based.

Difference in time to positivity of hub-blood versus nonhub-blood cultures is not useful for the diagnosis of catheter-related bloodstream infection in critically ill patients

OBJECTIVE

The differential time to positivity (DTTP), defined as the difference in time necessary for the blood cultures taken by a peripheral puncture and through the catheter to become positive has been suggested to be useful in differentiating between catheter-related bloodstream infection (CR-BSI) and other sources of bacteremia. A DTTP of >120 mins was found predominantly in CR-BSI. The objective of our study was to investigate whether DTTP is useful for the diagnosis of CR-BSI in a medical-surgical intensive care unit.

DESIGN

Prospective clinical study.

SETTING

A 60-bed medical-surgical intensive care unit of a university hospital.

PATIENTS

One hundred consecutive adult patients from whom catheter(s) were to be removed for suspected CR-BSI were studied.

INTERVENTION

A blood culture (using aerobic and anaerobic culture bottles) was first taken from a new puncture site. Next, a blood culture was taken through every intravascular catheter in place.

MEASUREMENTS AND RESULTS

DTTP was calculated using the automated BacT/Alert blood culture system. Three patients had CR-BSI and nine patients had noncatheter-related bacteremia. Five patients had catheter-related sepsis without proven bacteremia. There was no significant difference in median DTTP between patients with CR-BSI and noncatheter-related bacteremia (2.1 hrs and 3.3 hrs, respectively; p =.6). Moreover, catheter-related sepsis in patients without bacteremia could not be detected using DTTP.

CONCLUSION

DTTP seems not to be useful for the diagnosis of CR-BSI in a medical-surgical intensive care unit.

Randomized, double-blind trial of an antibiotic-lock technique for prevention of gram-positive central venous catheter-related infection in neutropenic patients with cancer

The aim of the present study was to determine the efficacy of an antibiotic-lock technique in preventing endoluminal catheter-related infection with gram-positive bacteria in neutropenic patients with hematologic malignancies. Patients with nontunneled, multilumen central venous catheters were assigned in a randomized, double-blinded manner to receive either 10 U of heparin per ml (57 patients) or 10 U of heparin per ml and 25 microg of vancomycin per ml (60 patients), which were instilled in the catheter lumen and which were allowed to dwell in the catheter lumen for 1 h every 2 days. Insertion-site and hub swabs were taken twice weekly. The primary and secondary end points of the trial were significant colonization of the catheter hub and catheter-related bacteremia, respectively. Significant colonization of the catheter hub occurred in nine (15.8%) patients receiving heparin (seven patients were colonized with Staphylococcus epidermidis, one patient was colonized with Staphylococcus capitis, and one patient was colonized with Corynebacterium sp.), whereas the catheter hubs of none of the patients receiving heparin and vancomycin were colonized (P = 0.001). Catheter-related bacteremia developed in four (7%) patients receiving heparin (three patients had S. epidermidis bacteremia and one patient had S. capitis bacteremia), whereas none of the patients in the heparin and vancomycin group had catheter-related bacteremia (P = 0.05). The times to catheter hub colonization and to catheter-related bacteremia by the Kaplan-Meier method were longer in patients receiving heparin and vancomycin than in patients receiving heparin alone (P = 0.004 and P = 0.06, respectively). Our study shows that a solution containing heparin and vancomycin administered by using an antibiotic-lock technique effectively prevents catheter hub colonization with gram-positive bacteria and subsequent bacteremia during chemotherapy-induced neutropenia in patients with hematologic malignancy.

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.

Infection control and outpatient parenteral antibiotic therapy

Outpatient procedures have become more complex, requiring outpatient providers to offer technical procedures in the home, office, and clinic. This shift in health care has brought about the need for staff members to become proficient in a variety of technical procedures that were once done only in the hospital setting. Outpatient i.v. therapy has caused home health care agencies, physicians' offices, and clinics to seek education and training regarding i.v. therapy and to develop basic infection-control guidelines and guidelines related to the insertion and maintenance of i.v. devices. The goals of the outpatient provider are to prevent i.v.-related complications and to provide quality patient care. These can be accomplished by strict adherence to sound infection-control guidelines and routine monitoring of procedure techniques and complications of care. Outpatient providers may wish to seek expertise and guidance from hospital infection-control personnel, infectious diseases specialists, or other infection-control consultants to meet the demands of the complexity of outpatient care.

Catheter-related infections in long-term catheterized dogs. Observations on pathogenesis, diagnostic methods, and antibiotic lock technique

BACKGROUND

Intravascular catheters are associated with severe infections in patients, but only few reports on this problem in animal research exist.

OBJECTIVE

We report on catheter-related bacterial colonization and its consequences in long-term catheterized animals.

MATERIAL AND METHOD

Foxhounds were instrumented with intravascular catheters and flow probes to study the regulation of renal blood flow and pressures.

RESULTS

After flushing the catheters, alterations in renal blood flow were observed and these could be related to bacterial colonization of intravascular catheters with Pseudomonas species. After attention had been focused on aseptic technique in all experimental phases and prophylactic antibiotic lock instituted, the occurrence of Pseudomonas bacteremia ceased, and the magnitude and incidence of catheter-related colonization and infection by Pseudomonas species dropped considerably.

CONCLUSION

The catheter-related colonization that occurred spontaneously in these animals resembled findings in animal experiments in which catheter-related infections were deliberately induced as well as observations made with regard to catheter-related infections in patients. This report emphasizes the importance of asepsis when working with animals with long-term intravascular catheters. We suggest that monitoring for this complication, e.g., by means of catheter cultures at the time of removal, should routinely be part of protocols for animal experiments using long-term intravascular catheters.

Clonal expansion of Staphylococcus epidermidis strains causing Hickman catheter-related infections in a hemato-oncologic department

The detailed analysis of 411 strains of coagulase-negative staphylococci (CoNS) obtained from 40 neutropenic hemato-oncologic patients (61 Hickman catheter episodes) on intensive chemotherapy is described. By random amplification of polymorphic DNA (RAPD) analysis, a total of 88 different genotypes were detected: 51 in air samples and 30 in skin cultures prior to insertion, 12 in blood cultures after insertion, and only 5 involved in catheter-related infections (CRI). Two RAPD genotypes of Staphylococcus epidermidis predominated, and their prevalence increased during patient hospitalization. At insertion, these clones constituted 11 of 86 (13%) CoNS isolated from air samples and 33 of 75 (44%) CoNS isolated from skin cultures. After insertion, their combined prevalence increased to 33 of 62 (53%) in catheters not associated with CRI and 139 of 188 (74%) in catheters associated with CRI (P = 0.0041). These two predominant S. epidermidis clones gave rise to a very high incidence of CRI (6.0 per 1,000 catheter days) and a very high catheter removal rate for CRI, 70%, despite prompt treatment with vancomycin. A likely source of S. epidermidis strains involved in CRI appeared to be the skin flora in 75% of cases. The validity of these observations was confirmed by pulsed-field gel electrophoresis (PFGE) of SmaI DNA macrorestriction fragments of blood culture CoNS isolates. Again, two predominant CoNS genotypes were found (combined prevalence, 60%). RAPD and PFGE yielded concordant results in 75% of cases. Retrospectively, the same two predominant CoNS clones were also found among blood culture CoNS isolates from the same hematology department in the period 1991 to 1993 (combined prevalence, 42%) but not in the period 1978 to 1982. These observations underscore the pathogenic potential of clonal CoNS types that have successfully and persistently colonized patients in this hemato-oncology department.

The use of continuous monitoring blood culture systems in the diagnosis of catheter related sepsis

AIM

To assess whether the information provided by automated continuous monitoring blood culture systems could aid in the diagnosis of catheter related sepsis.

METHODS

Serial dilutions of a strain of coagulase negative staphylococcus were inoculated into the BacT/Alert blood culture system. Blood culture results for seven patients with possible catheter related sepsis from coagulase negative staphylococci were reviewed.

RESULTS

Time to positivity and length of lag period were strongly related to the concentration of bacteria inoculated (average decrease of 1.5 hours to positivity for each 10-fold increase in concentration). Time to positivity and length of lag period were significantly shorter for central line blood cultures than for those taken from peripheral sites.

CONCLUSIONS

Using data already measured by continuous monitoring blood culture systems may provide a simple alternative to quantitative blood cultures for the diagnosis of catheter related sepsis.

Catheter-related infection: an update on diagnosis, treatment, and prevention

Catheter-related infection (CRI) accounts for a large percentage of nosocomial infections, and related bacteremia is a common complication. Bacteremia arises in approximately 1 of 15 episodes of CRI and causes considerable morbidity and occasional mortality, as well as increased medical costs. The diagnosis of CRI and catheter-related bacteremia (CRB) is still a challenge for practitioners treating catheterized patients. Semiquantitative tip culture by the roll-plate method is the cornerstone for diagnosis of CRI in routine practice. However, there is a great deal of interest in the alternative methods for diagnosing CRI without catheter withdrawal, since treatment of the patient can be successfully completed with the infected device maintained in place. The conservative management of CRI includes perfusion of antibiotics through the infected catheter and the antibiotic-lock technique (ALT). Catheter-related infection prevention is accomplished mainly by strict adherence to hygienic practices in insertion and manipulation of the catheter. However, knowledge of the pathophysiology of CRI has led to the development of new sophisticated catheters and hubs that incorporate mechanical and antibacterial barriers.

Infection versus colonization in the critical care unit

Serious infections in the critical care unit are commonplace. However, distinguishing true infection from mere colonization is a difficult and often uncertain process that has been shown to result in both over- and under-treatment of patients. Antimicrobial agents used in the CCU setting are expensive and not without toxicities. This article discusses methods to differentiate colonization from infection.

Central venous catheter-related septicaemia in paediatric cancer patients

A prospective study of septicaemia, with special reference to central venous catheter (CVC)-related septicaemia, was performed over a nine-month period in paediatric cancer patients undergoing anti-neoplastic therapy. A total of 142 patients with 153 CVCs were included in the study. Seventy-two episodes of septicaemia were detected in 66 patients; overall, 46% of patients developed one or more episodes of septicaemia. Thirty-nine (54%) of these episodes occurring in 34 patients were CVC-related. Twenty-one (29%) of the episodes occurring in twenty patients were probably unrelated to CVCs and 12 (17%) episodes in 12 patients were of uncertain source. A total of 22932 CVC days were studied. The rate of CVC-related septicaemia was 1.7 episodes/1000 catheter days. Gram-positive organisms were commonest, causing 34 (87%) episodes of CVC-related septicaemia. Twenty-five (71%) of 35 evaluable episodes were successfully treated with antibiotics without CVC removal. Two patients died, CVC related sepsis probably contributing to death, and one patient suffered prolonged morbidity associated with CVC sepsis. Gram-negative organisms were the commonest cause of CVC-unrelated septicaemia, being implicated in 13 (62%) episodes.

Prevention of catheter sepsis: the hub

The prevention of catheter sepsis lies in a sound understanding of the routes through which catheters get contaminated. The catheter hub has been recognized as a portal for microorganisms causing catheter sepsis, particularly in central venous catheters inserted for > 1 wk. Bacteria and fungi may reach the internal surface of the catheter connector during manipulation by hospital staff and then colonize the entire lumen of the catheter. Endoluminal contamination has diagnostic, therapeutic, and preventive implications. Some traditional preventive approaches (site care, subcutaneous cuffs and tunnels, maximal aseptic barriers at the time of catheter insertion, and external antiseptic or antibiotic coating) may fail because they focus solely on the skin as a source of bacteria. Hub-related catheter sepsis can be prevented by aseptic hub manipulation, appropriate junction protection, and by reducing the number of catheter lumens, side ports, three-way stopcocks, and changes of the infusion sets. Needleless systems must be evaluated in terms of their safety in preventing endoluminal contamination. A new disinfecting catheter hub incorporating an antiseptic barrier has been developed and reduced hub-related catheter sepsis by more than 90%. The endoluminal route of intravascular catheter contamination must be taken into account when designing strategies for the diagnosis and prevention of catheter-related sepsis.

Diagnosis of vascular catheter-related bloodstream infection: a meta-analysis

Catheter-related bloodstream infections increased in incidence during the past decade, causing significant morbidity, mortality, and excess hospital costs. Absence of inflammation at the catheter site in most cases makes clinical diagnosis uncertain. The relative accuracy and cost-effectiveness of different microbiologic tests for confirming that bloodstream infection is catheter related have remained unclear. A meta-analysis of published studies was conducted regarding the accuracy of diagnostic test methods using pooled sensitivity and specificity and summary receiver operating characteristic (ROC) curve analysis. The cost for each test was estimated by methods published by the College of American Pathologists. Costs of catheter replacement and antibiotic therapy for false positive results were included in the cost per accurate test result. Twenty-two studies evaluating six test methods met inclusion criteria for the meta-analysis. Accuracy increased in ROC analysis for catheter segment cultures with increasing quantitation (P = 0.03) (i.e., quantitative > semiquantitative > qualitative) largely due to an increase in specificity. The highest Youden index (mean = 0.85) was observed with quantitative catheter segment culture, the only method with pooled sensitivity and specificity above 90%. For blood culture methods, there was no statistically significant trend toward increased accuracy. The unpaired quantitative catheter blood culture offered the lowest cost per accurate test result but was only 78% sensitive. In conclusion, quantitative culture was the most accurate method for catheter segment culture, and unpaired quantitative catheter blood culture was the single most cost-effective test, especially for long-term catheters.

A review of 560 Hickman catheter insertions

Indwelling, cuffed, tunnelled, central venous (Hickman) catheters are increasingly being used for venous access and the administration of chemotherapy for oncological patients. This paper reviews the technical problems associated with the percutaneous insertion of these catheters and the complications arising from their use. Five hundred and sixty catheters were inserted; 31.3% had complications at insertion, most commonly precipitation of an arrhythmia (13.9%). Arterial puncture occurred in 3.8% and pneumothorax in 1.6%. Catheters remained in place for a median period of 91 days. Forty percent of catheters were removed electively on completion of treatment; 30.2% required removal because of complications, which included sepsis, migration, thrombosis and blockage. Twenty percent of patients died with their catheter in place, 8.5% were still in situ and 1.6% were removed because of patient non compliance. Sepsis remains the commonest, long term complication, with staphylococcus epidermidis being the organism isolated most frequently. There were no catheter-related deaths.

A clinical trial on the prevention of catheter-related sepsis using a new hub model

BACKGROUND

Catheter hub contamination is being increasingly recognized as a source of catheter-related sepsis. The authors have investigated the efficacy of a new hub design in preventing endoluminal catheter contamination and catheter-related sepsis arising at the hub.

METHODS

Adult surgical and intensive care patients requiring a subclavian catheter for at least 1 week were randomly assigned to receive catheters with standard connectors (control group, n=73) or equipped with a new hub model (new hub group, n=78). Skin, catheter tip, and hub cultures were performed at the time the catheter was withdrawn because therapy was terminated or because of suspicion of sepsis, in which case peripheral blood cultures were taken.

RESULTS

Of the 151 patients included, 15 (10%) developed catheter-related sepsis. Catheters were more often withdrawn because suspicion of infection in the control group (42 vs. 19%, p<0.005). Catheter sepsis rate was higher in the control group (16 vs. 4%, p<0.01) because of the low rate of catheter sepsis arising at the hub observed in the new hub group (1 vs. 11%, p<0.01). The prevalence of culture-positive catheter hubs without associated bacteremia (colonization) was higher in the control group (18 vs. 5%, P<0.03).

CONCLUSIONS

A new catheter hub has proved to be useful in preventing endoluminal bacterial colonization and catheter-related sepsis in subclavian lines inserted for a mean of 2 weeks.

Diagnosis of catheter-related infections

Catheter-related infections (CRI) are a major cause of febrile episodes in hospitalized patients. Additionally, approximately 40% of primary infections in intensive care patients are directly related to central venous catheters. Despite the clinical significance of CRI diagnostic procedures are still under debate. Clinical diagnosis which includes systemic signs of infection and suppuration at the catheter entry site is altogether a rare event. Therefore, most cases are still diagnosed by laboratory methods. Although the semiquantitative roll-plate technique is widely used and frequently regarded as gold standard, the disadvantages of a post-hoc diagnosis are obvious. In-situ techniques which leave the suspected catheter in place include differential blood cultures, skin and hub cultures and a new method of microscopic screening of blood drawn through the inflicted catheter. However, until now the true value of all these methods still lack unanimous acceptance. Further research is necessary to close the gap between clinical expectations and laboratory results.

Central venous catheter practices: results of a survey

BACKGROUND

The incidence of nosocomial bloodstream infections has increased twofold to threefold in the past decade, and central venous catheter infections account for about 90% of catheter-related nosocomial bloodstream infections. Many studies of risk factors for central venous catheter complications have been conducted, resulting in recommendations for preventive strategies, but few data are available regarding the frequency with which such strategies are employed in clinical practice.

METHODS

A survey was conducted of persons attending a meeting of the National Association of Vascular Access Networks in New Orleans on September 25, 1992. The survey contained 15 questions related to central venous catheters regarding infection control measures, measures to maintain patency, and use of the catheter for obtaining blood specimens for diagnostic tests.

RESULTS

Ninety-two persons from 24 states completed the questionnaire as representatives of 23 teaching hospitals, 21 nonteaching hospitals, and 48 home health agencies. Transparent dressings were used more frequently (88%) than cotton gauze (27%). Alcohol and povidone-iodine solutions were the most frequently used antiseptics. Antimicrobial ointment was used by fewer than half; of these 86% used povidone-iodine and 26% used polymyxin-neomycin-bacitracin. Heparin flushes were still being used by 97% to maintain patency. Most (82%) used central venous catheters to draw blood cultures; of these, 68% drew only qualitative cultures and 32% drew quantitative cultures in addition to or instead of qualitative cultures.

CONCLUSIONS

Significant diversity of practice was documented among the health care organizations represented in this survey. Some of the practices documented in this survey have been associated with higher rates of bloodstream infection; this may partially explain the observed increase during the past decade in the incidence of nosocomial bloodstream infections.

Guidelines for good practice in central venous catheterization. Hospital Infection Society and the Research Unit of the Royal College of Physicians

Central venous catheters (CVC) are commonly used in clinical practice and are associated with several complications, including early and late onset infection. In these guidelines, an outline of good practice for the use of CVC and the prevention of associated infections is presented. Definitions of both localized and systemic catheter-related sepsis are given. Subsequent good practice in relation to the insertion of CVC, including patient preparation, planned duration of catheterization, catheter materials and design of the CVC, are presented. Skin fixation and insertion site care, including the use of dressings and administration sets, as well as an approach to flow obstructions, are also reviewed. The clinical and microbiological diagnosis of catheter-related sepsis and its treatment is next presented. Finally, guidelines for CVC removal and replacement are given. The guidelines are designed to facilitate the development of good practice in the use of CVC, allowing appropriate protocols to be formulated and to reduce infection risk.

Empiric treatment of localized infections in the febrile neutropenic patient with monotherapy

Empiric therapy is necessary for febrile, neutropenic patients in order to minimise morbidity and mortality. Certain agents are now available for monotherapy which offer comparable success to combinations of either an aminoglycoside with a beta-lactam or two beta-lactams. However, no regimen offers complete treatment under all circumstances in all patients. It is also apparent that febrile, neutropenic patients comprise a more heterogeneous group than just those with bacteraemia, clinically apparent infection and unexplained fever. Localized infections occur in just under a third of cases at the onset of fever and a similar number will develop during the course of fever. Mortality is higher in infections that are accompanied by bacteraemia and also those that develop subsequently, especially when related to the lung. The aetiological agent also differs with each type of infection as does the duration of fever and symptoms. Consequently modifications are required more often. The length of treatment may also differ. Therefore, during the first 3-4 days of empiric therapy, every effort should be made to identify incipient localized infections in addition to detecting bacteraemia. Changes in therapy can then be based on objective grounds rather than continued fever offering more patients individual treatment than is possible when relying only on the temperature chart.

Value of differential quantitative blood cultures in the diagnosis of catheter-related sepsis

A prospective study was performed to assess the value of differential quantitative blood cultures in the diagnosis of catheter-related sepsis when this condition is suspected on clinical grounds and to establish a reliable discriminative value for application without removal of the inserted catheter. A total of 107 central venous catheters from 64 patients were used for the study. Blood was obtained simultaneously through the suspected infected device and from a peripheral venipuncture. The catheter was removed and its tip cultured semiquantitatively. Catheter-related sepsis occurred in 17 patients. Using as cut-off value a colony count fourfold higher in blood drawn through the catheter than in simultaneously drawn peripheral blood, a sensitivity of 94%, specificity of 100% and positive predictive value of 100% were obtained. A single bacterial count greater than 100 cfu/ml in the quantitative culture of the catheter blood specimen in the presence of a positive qualitative peripheral blood culture of the same organism was also highly suggestive of catheter-related sepsis. Differential quantitative blood culture is a reliable method for the diagnosis of catheter-associated sepsis without catheter removal.

Selective oral antimicrobial prophylaxis for the prevention of infection in acute leukaemia-ciprofloxacin versus co-trimoxazole plus colistin. The EORTC-Gnotobiotic Project Group

230 leukaemic patients were entered into a randomised, prospective, multicentre trial of either ciprofloxacin (1 g/day) or co-trimoxazole (1920 mg/day) plus colistin (800 mg/day) for the prevention of infection during granulocytopenia. Bacteraemia due to resistant gram-negative rods occurred only in the co-trimoxazole-colistin group though both regimens were effective for selective gastrointestinal tract decontamination. However, there were fewer patients without any infective complications (31% vs. 18%: P = 0.02), fewer febrile days [mean (S.D.) 5.9 (1.1) vs. 8.2 (1.4): P = 0.0242], a lower proportion of infective events (0.9 (0.16) vs. 1.2 (0.18): P = 0.005) and fever occurred later (median 19 vs. 14 days: 0.025 less than P less than 0.05) in the co-trimoxazole-colistin group. The choice of prophylactic regimen therefore appears to depend upon whether or not protection against gram-negative infection is required or better systemic prophylaxis overall.

Vascular catheter-related sepsis: diagnosis and prevention

Although catheter-related sepsis (CRS) is an important cause of nosocomial infection and the major complication of intravenous catheter use, there is, as yet, no consensus concerning either a useful definition of CRS or the optimal method of catheter management and prevention of infection. Semiquantitative culture of catheter tips is a useful method of diagnosis of CRS but other techniques such as quantitative catheter blood cultures and Gram staining of the catheter have roles in selected patients. The most significant impact on the prevention of CRS is made by the introduction of an intravenous therapy team. The site and method of catheter insertion, type of dressing and antisepsis, catheter flushing and use of prophylactic antibiotics are also important issues. Techniques such as guide-wire exchange and catheters such as triple lumen and total implantable venous access devices have their own infection problems. Many new and interesting approaches to the prevention of CRS are being formulated. To facilitate further progress, a standardized definition for diagnosis, and revised recommendations for prevention of CRS would be helpful.

Routine semiquantitative cultures and central venous catheter-related bacteremia

Semiquantitative cultures were compared with blood cultures during one year in order to see if the routine use of a semiquantitative catheter culture method (SQC) in unselected patients can detect or predict infection associated with central venous catheters. Catheter infection, i.e. greater than or equal to 15 colony forming units (cfu) per plate, occurred in 137 of 542 catheter tips (25%), mainly with coagulase-negative staphylococci. Catheter-associated bacteremia occurred in 17 of 93 cases (18%) where blood cultures had been drawn. In 15 of these, the catheter tip grew greater than or equal to 15 cfu. The predictive value for bacteremia of a positive SQC was only 21%. SQC is not a suitable method for the detection of catheter-associated bacteremia, but may be an indicator of the standard of central venous catheter hygiene.