Central venous catheters: preventing infection and occlusion

As central venous catheters (CVCs) become more widely used in today's healthcare environment, nurses require expert knowledge in relation to CVC maintenance to prevent complications and maximize efforts to optimize the individual's health status. This is especially so since CVCs have begun to be used outside intensive care units, e.g. in general wards, and can be associated with high incidences of infection, occlusion and subsequent compromise in patient health. Nurses are responsible for the maintenance and use of central access devices, such as CVCs, resulting in a need for literature specific to the nursing aspects of CVC management. This article addresses many nursing issues pertaining to care of the central line, focusing on evidence- and research-based literature, and also reviews the literature to make recommendations for practice.     

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.     

Brushing has made a sweeping change: use of the endoluminal FAS brush in haemodialysis central venous catheter management.

Common usage of central venous catheter (CVC) access for haemodialysis has presented the haemodialysis nurse with the challenge of maintaining CVCs as a viable form of access. The major complications seen with CVC use are obstruction and infection. A project was undertaken to identify the usefulness of the endoluminal fibrin analysis system (FAS) brush as an intervention in haemodialysis CVC management. The aims of the study were to identify: the reasons for brushing CVCs and the number of occasions brushing is indicated; how successful brushing is in unblocking and improving flow from CVCs, and the length of time the catheter remains patent following successful declotting. Seventeen patients were found suitable for CVC brushing and divided into two groups depending on the indication for brushing. In the group in which the catheter was brushed to restore flow, 73 per cent of brushings were successful, and in 50 per cent of those cases the CVC remained patent for 6 weeks. Sixty per cent of catheter brushings to improve flow were successful, and in 50 per cent of the CVCs flow was sustained over a 6-week period. Overall, the findings support the use of the endoluminal FAS brush for the applications trialled.     

Elective removal of cuffed central venous catheters in children

Background Subcutaneously tunneled, cuffed central venous catheters (CVCs) are commonly used in children undergoing cytotoxic chemotherapy or hematopoietic stem-cell transplantation. When their use is no longer indicated or precluded by mechanical or infectious complications, CVCs have to be removed. General instructions on how cuffed CVC should be removed are available in the medical texts but none is adapted for use in children. Materials and methods A literature search from the MEDLINE and EMBASE to identify articles describing the procedure of removing CVC or complications arising from the procedure was carried out. Results Specific guidance on the removal of CVC in children was not found. Venous air embolism appeared to be the most common complication associated with catheter removal but none involved pediatric patients. On the other hand, three out of the five incidents of catheter fracture with or without embolization happened in children. Conclusion Further studies are needed to define the optimal management of CVC removal in pediatric patients. A sequence of positioning the child, use of sedation, dissecting out the cuff, pulling off the catheter, closing the exit wound, and handling of the removed catheter is suggested.     

Central venous catheter removal: procedures and rationale

The use of central venous catheters (CVCs) has become fairly commonplace within both the hospital and community setting. The removal of these devices is often a task performed without much teaching and the procedure to follow is passed on from one nurse to another with little or no research on which to base actions. This article describes the potential complications associated with CVC removal and methods to prevent them. It will also give the nurse research-based procedures to follow when removing the various types of CVC. These written procedures should be used as a training guideline only. Practical training and supervision until competent is still required.     

Comparison of Heparin and Saline for Prevention of Central Venous Catheter Occlusion in Pediatric Oncology: A Systematic Review and Meta-Analysis

ObjectiveThe management of central venous catheter (CVC) occlusion remains an area without clear evidence-based guidelines. Studies have been conducted that compare the use of heparin and normal saline for reducing thrombosis, but the evidence is not strong enough to suggest a significant advantage of one over the other. Therefore, the study aimed to assess the effectiveness of heparin and normal saline flushing in preventing CVC occlusion in pediatric patients with cancer.Data SourcesA comprehensive search was conducted in PubMed, Web of Science, Cochrane, MEDLINE, CINAHL, Embase, World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov platform using specific keywords. The search was conducted until March 2022. Five randomized controlled trials are included in this study.ConclusionFive studies with a total of 316 pediatric cancer patients met the inclusion criteria. The studies were found to be heterogeneous due to variations in the types of cancer, heparin concentration, flushing frequency of CVCs, and methods used to measure occlusion. Despite these differences, there was no significant difference in the effect of flushing with heparin and normal saline in preventing CVC occlusion. The analysis revealed that normal saline is as effective as heparin in preventing CVC occlusion among pediatric cancer patients.Implications for Nursing PracticeThis systematic review and meta-analysis demonstrated that there is no significant difference between the use of heparin and normal saline flushing in preventing CVC occlusion among pediatric cancer patients. Considering the potential risks of heparin, the use of normal saline flushing may be recommended to prevent CVC obstruction.     

A simplified method of antibiotic lock therapy for Broviac–Hickman catheters using a CLC 2000 connector device

Introduction We report a simplified method of performing antibiotic lock therapy (ALT) based on a disposable central venous catheter (CVC) hub device, CLC 2000, enabling an open-ended CVC to be flushed with normal saline solution without heparin. Methods ALT was administered through a CLC 2000 connector for recurrent CVC-bloodstream infections (BSI) by the same organism in four patients and for CVC colonization in five patients. Results The antibiotic concentration obtained in the lumen of the CVC with ALT was 2,500-fold higher than the minimum inhibiting concentration of targeted bacteria for patients treated with vancomycin, 2,500–80,000-fold higher for patients treated with teicoplanin, and 10,000-fold higher for the patient treated with amikacin. All CVC-BSIs treated with ALT resulted in complete clinical and microbiological responses. No case of malfunction in withdrawing or flushing the CVC and no precipitation during the administration of the antibiotic solution was observed. No recurrence of CVC-BSI or CVC colonization by the same organism was diagnosed during subsequent follow-up, despite the fact that all patients had further periods of severe neutropenia. At the last follow-up, three CVCs had been removed for other infections (fever of unknown origin in two; fungemia in one), four CVCs had been removed at the end of therapy, and one CVC is still in situ 20 months after ALT. Conclusions In conclusion, a course of ALT is feasible in cancer patients with infected but much-needed CVCs before resorting to removal. The use of the CLC 2000 connector device simplifies the procedure for preparation and administration of ALT without compromising its efficacy.     

Increased rate of central venous catheterization procedures in community EDs

Objective

Central venous catheterization (CVC) is integral to the emergency department (ED) treatment of critically ill patients, such as those receiving early goal-directed therapy for severe sepsis. No previous studies have described the overall use of CVC in community EDs. The objective of this study was to estimate the overall frequency and temporal trends in CVC use in a sample of patients visiting community EDs.

Methods

This was a retrospective observational study of 2.97 million patient visits at 28 community EDs (range of annual visits, 10?837-110?136) from January 2004 to February 2008. Data were obtained from a community-based research consortium. Central venous catheterization procedures were aggregated at the hospital level for each study year. Trends in CVC use were evaluated using linear regression.

Results

Three thousand four hundred eighty-nine patient visits (0.12% of all ED patient visits) had a CVC procedure performed in the ED. The overall rate of CVC procedures per 1000 ED patient visits increased from 0.87 (95% confidence interval [CI_95%], 0.80-0.95) in 2004 to 1.62 (CI_95%, 1.38-1.91) procedures in 2008 (P value for trend = .003). There was wide variability in the frequency of CVC procedures performed among EDs, ranging from a low of 0.27 (CI_95%, 0.18-0.42) to a high of 7.58 (CI_95%, 6.27-9.17) procedures per 1000 ED visits. The CVC procedure rates were lower in the 8 rural EDs (0.99 CVCs per 1000 ED patient visits [CI_95%, 0.91-1.07] compared with the 20 urban EDs (1.22 CVCs [CI_95%, 1.18-1.27]; P < .001). An increasing rate of CVC procedures during the study period was observed in urban EDs (0.84-1.94 CVCs per 1000 ED patient visits; P value for trend = .005) but not in rural EDs (1.1-0.93; P value for trend = .41) during the study period.

Conclusion

The overall rate of CVC increased from 2004 to 2008. However, there was a wide variation among Eds, and the CVC rate was lower in rural compared with urban EDs. The increase in CVC use in urban EDs may reflect more intensive therapy in the management of ED patients with acute illness or injury. Future efforts are needed to optimize best practices for the use of CVC in community ED practices and to characterize factors responsible for urban rural differences in the rate of CVC procedures.     

Decrease in central venous catheter placement due to use of ultrasound guidance for peripheral intravenous catheters

Study Objectives

Obtaining intravenous (IV) access in the emergency department (ED) can be especially challenging, and physicians often resort to placement of central venous catheters (CVCs). Use of ultrasound-guided peripheral IV catheters (USGPIVs) can prevent many “unnecessary” CVCs, but the true impact of USGPIVs has never been quantified. This study set out to determine the reduction in CVCs by USGPIV placement.

Methods

This was a prospective, observational study conducted in 2 urban EDs. Patients who were to undergo placement of a CVC due to inability to establish IV access by other methods were enrolled. Ultrasound-trained physicians then attempted USGPIV placement. Patients were followed up for up to 7 days to assess for CVC placement and related complications.

Results

One hundred patients were enrolled and underwent USGPIV placement. Ultrasound-guided peripheral IV catheters were initially successfully placed in all patients but failed in 12 patients (12.0%; 95 confidence interval [CI], 7.0%-19.8%) before ED disposition, resulting in 4 central lines, 7 repeated USGPIVs, and 1 patient requiring no further intervention. Through the inpatient follow-up period, another 11 patients underwent CVC placement, resulting in a total of 15 CVCs (15.0%; 95 CI, 9.3%-23.3%) placed. Of the 15 patients who did receive a CVC, 1 patient developed a catheter-related infection, resulting in a 6.7% (95 CI, 1.2%-29.8%) complication rate.

Conclusion

Ultrasound prevented the need for CVC placement in 85% of patients with difficult IV access. This suggests that USGPIVs have the potential to reduce morbidity in this patient population.     

Venous air embolism from central venous catheterization: a need for increased physician awareness.

OBJECTIVES: To report a series of patients with clinically diagnosed venous air embolism (VAE) and major sequelae as a complication of the use of central venous catheters (CVCs), to survey health care professionals' practices regarding CVCs, and to implement an educational intervention for optimizing approaches to CVC insertion and removal. SETTING: Tertiary care, university-based 806-bed medical center. INTERVENTIONS: We surveyed 140 physicians and 53 critical care nurses to appraise their awareness of the proper management and complications of CVCs. We then designed, delivered, and measured the effects of a multidisciplinary educational intervention given to 106 incoming house officers. MEASUREMENTS AND MAIN RESULTS: Although most physicians (127, 91%) chose the Trendelenburg position for CVC insertion, only 42 physicians (30%) reported concern for VAE. On CVC removal, only 36 physicians (26%) cited concern for VAE. Some physicians (13, 9%) reported elevating the head of the bed during CVC removal, possibly increasing the risk of VAE. Awareness of VAE or its prevention did not correlate with the level of physician training, experience, or specialty. After the educational intervention, concern for and awareness of proper methods of prevention of VAE improved (p < .001). At 6-month follow-up, reported use of the Trendelenburg position continued, but concern cited for VAE had returned to baseline. CONCLUSIONS: There is inadequate awareness of VAE as a complication of CVC use. Focused instruction can improve appreciation of this potentially fatal complication and knowledge of its prevention, but the effect declines rapidly. To achieve a more sustained improvement, a more intensive, hands-on, periodic educational program will likely be necessary, as well as reinforcement through enhanced supervision of CVC insertion and removal practices.     

Infective and thrombotic complications of central venous catheters in patients with hematological malignancy: prospective evaluation of nontunneled devices

Goals  Central venous catheter (CVC)-related bloodstream infection (CR-BSI) is a significant complication in hematology patients. A range of CVC devices may be used, and risks for the development of complications are not uniform. The objectives of this study were to determine the natural history and rate of CVC-related complications and risk factors for CR-BSI and to compare device-specific complications in a hematology population. Patients and methods  An observational cohort of patients with hematologic malignancy was prospectively studied following CVC insertion. Participants were reviewed until a CVC-related complication necessitated device removal, completion of therapy, death, or defined end-of-study date. The National Nosocomial Infection Surveillance definition for CR-BSI was used. Overall and device-specific rates of infective and noninfective complications were calculated and potential risk factors were captured. Main results  One hundred six CVCs (75 peripherally inserted central venous catheters [PICCs], 31 nontunneled CVCs) were evaluated in 66 patients, over 2,399 CVC days. Thrombosis occurred in 16 cases (15.1%), exit-site infection in two (1.9%), and CR-BSI in 18 (7.5 per 1,000 CVC days). No significant differences were found when complication rates in PICC and nontunneled devices were compared. An underlying diagnosis of acute myeloid leukemia was negatively associated with CR-BSI (odds ratio (OR) 0.14, p = 0.046), and a previous diagnosis of fungal infection was associated with infection (OR 22.82, p = 0.031). Conclusions  CR-BSI rates in our hematology population are comparable to prior reports. A low rate of exit-site infection and high proportion of thrombotic complications were observed. No significant differences in thrombotic or infective complications were evident when PICC and nontunneled devices were compared. PICC devices are a practical and safe option for management of hematology patients.     

Do position control methods for central venous catheters prevent complications? Hydromediastinum caused by an initially correctly placed tri-lumen subclavian catheter by using intra-atrial ECG recording--a case report

Central venous catheters (CVCs) can be associated with various complications which arise during insertion, with the catheter in situ or upon its removal. Here we report a case of secondary CVC malposition that occurred despite checks of CVC position by different methods. A subclavian triple-lumen catheter was retracted until intra-atrial ECG indicated reversal to a normal P-wave. Blood was successfully aspirated through all three lumens, and the catheter was fixed at 11 centimeters intracorporal length and used intraoperatively. A postoperative chest X-ray demonstrated an intravenous CVC length of only a few centimeters, which was accepted because of the inconspicuous results of previous monitoring. Fifteen hours after CVC insertion, the patient developed a swelling in the subclavian and right neck region, a pronounced hydromediastinum and small bilateral pleural effusions caused by paravenous infusion through the most proximal CVC lumen. After instantaneous removal of the catheter, the patient recovered without further complications. This case demonstrates that even carefully-fixed multi-lumen catheters can partially dislocate due to a patient's movements or changes of position. Therefore, repeated aspiration of blood from the most proximal lumen should be performed to detect secondary CVC malposition. Moreover, repeated chest radiographs are useful in verifying a correct CVC position and detecting late complications. In summary, CVC complications can occur with delay, are potentially life-threatening and may necessitate repeated checks of catheter position. This case report discusses different approaches to detecting malposition and reviews rare CVC complications.     

Central venous catheter use

Central venous catheters (CVCs) are used with increasing frequency in the intensive care unit and in general medical wards. Catheter infection, the most frequent complication of CVC use, is associated with increased morbidity, mortality, and duration of hospital stay. Risk factors in the development of catheter colonisation and bloodstream infection include patient factors (increased risk associated with malignancy, neutropenia, and shock) and treatment-related factors (increased risk associated with total parenteral nutrition, ICU admission for any reason, and endotracheal intubation). Other risk factors are prolonged catheter indwelling time, lack of asepsis during CVC insertion, and frequent manipulation of the catheter. The most important factor is catheter care after placement. Effects of CVC tunnelling on infection rates depend to a large extent on indwelling time and the quality of catheter care. Use of polyurethane dressings can increase the risk of colonisation compared to regular gauze dressing. Thrombus formation around the CVC tip increases the risk of infection; low-dose anticoagulants may decrease this risk. New developments such as CVC impregnation with antibiotics may reduce the risk of infection. Reducing catheter infection rates requires a multiple-strategy approach. Therefore, ICUs and other locations where CVCs are used should implement strict guidelines and protocols for catheter insertion, care, and maintenance.     

Use of ultrasound to place central lines

CONTEXT: Placement of central venous catheters (CVCs) is an integral part of care for the critically ill patient but is associated with significant morbidity when using the traditional landmark method. The use of real-time ultrasound to guide line placement has been developed in hopes of avoiding this morbidity. OBJECTIVE: The objectives of this article are 2-fold. The first is to determine the relative effectiveness of the use of real-time ultrasound to place CVCs compared with the use of landmarks alone. The second is to discuss the merits of future study to increase the use of this technology. DATA SOURCES: Medline from 1966 to 2001, personal files, 2 prior systematic reviews, and reference lists of selected articles. STUDY SELECTION: Studies were included if: (1) study design was a controlled trial, (2) patients required placement of a CVC, (3) the interventions were real-time ultrasound versus standard landmark-guided line placement, and (4) outcomes included at least 1 of failure to place catheter, success of first attempt, number of attempts, time to catheter placement, or complication rate. DATA SYNTHESIS: Eighteen trials were identified. Pooled results showed a significant reduction in failure rate (risk difference, -.12, 95% confidence interval [CI], -.18 to -.06), number of attempts (risk reduction, 1.41, 95% CI, 1.15-1.67), and arterial puncture rate (risk difference, -.07, 95% CI, -.10 to -.03). The number of successful venous cannulations on first attempt were higher using ultrasound (risk difference,.24, 95% CI,.08-.39). No difference was found in time to insertion. Significant heterogeneity of study results was found for most analyses. Subgroup analyses suggested that ultrasound improved outcomes most convincingly using external probes, for internal jugular vein cannulation, and when used by clinicians less experienced at line placement. CONCLUSIONS: Adoption of real-time ultrasound to guide CVC placement has the potential to improve successful line placement and minimized complications. It can improve patient safety. However, there are significant cost concerns and the reported adverse events are generally minor and easy to treat. Before creating study protocols to increase usage of this technology, both current usage and cost effectiveness should be determined.     

Strategic patient education program to prevent catheter-related bloodstream infection

Central venous catheters (CVCs) are used commonly for venous access during treatment, and catheter-related bloodstream infection (CRBSI) is a frequent, yet highly preventable, hospital-acquired infection. One of the performance elements of the Joint Commission's 2012 National Patient Safety Goals addresses the education of patients and family members on CVC care and management, as well as CRBSI prevention before a central catheter is inserted. This article presents the history and roles of the Infusion Therapy Team at the University of Texas MD Anderson Cancer Center in CVC care and describes an organized patient education program that plays a key part in the institution's strategy to reduce and prevent CRBSI. Institutional standard policies and procedures for patient care should be in compliance with guidelines of the Centers for Disease Control and Prevention and the Joint Commission before any patient educational initiative is implemented. Such standards will serve as a guide to set up, organize, and implement an effective program.     

Partial occlusion of indwelling central venous catheters

Partial occlusion of indwelling central venous catheters (CVCs) developed as a clinical problem following the trend to leave CVCs in place for the duration of intravenous therapy, which can last for more than 1 year in some cases. The primary manifestation of partial catheter occlusion is the ability to infuse but not aspirate fluids through an indwelling CVC. There is evidence that the problem is at least partially related to a residue of blood products deposited within some CVCs and implanted ports each time blood is aspirated or infused. Over time, these deposits may act as a ball valve when aspiration from the CVC is attempted while still allowing fluid or drug infusions. A preliminary investigation has indicated that this partial occlusion can be corrected by the use of a fibrinolytic drug to "cleanse" the CVC of residual blood products through lysis, thus restoring full CVC patency. Controlled studies are still needed to determine how often the CVC should be cleansed to prevent buildup of blood products in the indwelling CVC.     

Central venous catheter infections in patients with acute leukemia

BACKGROUND: Central venous catheters (CVCs) have become an essential tool for an appropriate management of patients with acute leukemia. Infectious complications are a major concern in patients treated for acute leukemia. Although CVC-related infections are considered to be a major source of infections during neutropenia (<500/microl), data regarding the incidence of CVC-related infections are rare in acute leukemia. PATIENTS AND METHODS: We analyzed nontunneled CVCs in 58 patients with acute leukemia (22 men/36 women) in 119 chemotherapy cycles from April 1996 to January 1998 in a prospective trial. Proven CVC-related infection was defined as the isolation of the same organism from peripheral blood and CVC tip. CVC infection was suspected or possible when exit site inflammation and positive blood culture or organisms typical for CVC infection were observed. RESULTS: Mean neutropenia/cycle was 16.3 days (SD 8.0). 178 CVCs with 2,576 CVC days (mean 14.5 days, SD 7.2 days) were used in 119 cycles. Fever occurred in 87 cycles (73%). Blood stream infection was proven in 31 out of 87 febrile episodes (26.1%) with 40 isolates (8 gram-negative, 31 gram-positive, 1 Candida spp.). Colonization of the CVC tip was observed in 24 CVC lines with 28 isolates (27 gram-positive, 1 gram-negative); however, proven CVC-related infections were observed in 5 episodes only, all with coagulase-negative staphylococci. In another 6 episodes, CVC-related infection was assumed (local inflammation and gram-positive blood culture). Six further episodes had typical blood isolates (4 coagulase-negative staphylococci, 1 Candida spp.) and were considered possible CVC-related infections. In none of the remaining afebrile 32 cycles was a CVC infection observed or suspected. CONCLUSION: Gram-positive organisms contributed to the majority of CVC-related infections (16 out 17 CVC infections); however, the overall incidence of CVC infections in acute leukemia patients was 6.5/1,000 CVC days only (1.9 proven/2.3 suspected/2.3 possible/1,000 CVC days).     

Each lumen is a potential source of central venous catheter-related bloodstream infection

OBJECTIVE: To determine the relative rates of microbial colonization of individual lumens in triple-lumen central venous catheters (CVCs) and calculate the chance of detecting catheter-related blood stream infection (CRBSI) if only one lumen is sampled. DESIGN: Prospective evaluation of CVCs from suspected and nonsuspected CRBSI cases. SETTING: University teaching hospital. PATIENTS: Triple-lumen CVCs from 50 cases of suspected CRBSI (a raised peripheral white blood cell count, temperature >37 degrees C, and/or local signs of infection at the catheter skin entry site) were evaluated. For comparison, 50 triple-lumen CVCs routinely removed at the end of use were evaluated. MEASUREMENTS: In both groups, peripheral blood cultures were taken before CVC removal. After CVC removal, each lumen was sampled in vitro using the endoluminal brush, and the tip was then cultured using the Maki roll technique. MAIN RESULTS: CVCs causing CRBSI had significant microbial colonization in one, two, or three lumens in ten (40%), ten (40%), or five (20%) cases, respectively. Overall, random sampling of only one lumen in CVCs causing CRBSI had a 60% chance of detecting significant colonization. CONCLUSIONS: If only one CVC lumen is sampled, a negative result does not reliably rule out infection. Each lumen of multiple-lumen CVCs should be considered as a potential source of CRBSI.     

Learning why patients with central venous catheters resist permanent access placement

Central venous catheters (CVCs) are a well-known risk to patients on hemodialysis due to their higher morbidity and mortality compared to fistulas or grafts. One factor in the prevalence of CVCs is patients eligible for permanent access who refuse referral and permanent access placement. Objectives of this study were to identify reasons patients resist permanent access placement and develop potential strategies for intervention. A survey was distributed to Fresenius Medical Care North America (FMCNA) outpatient dialysis facilities (approximately 1600 facilities) requesting voluntary participation in documenting reasons given by patients for resisting permanent access placement. From the patient survey results, responses were collected and ranked from most frequent response to least frequent response. A collaborative workgroup of nephrology nurses and social workers reviewed the survey results. The patient survey provided 1573 responses. The three most frequently provided reasons were 1) a previous negative surgical experience, 2) having a permanent access placed in the past that did not work, and 3) cannulation fear and/or pain concerns. The workgroup identified best practices from clinics with low CVC rates and reviewed professional literature as a guide for development of potential strategies for intervention by the nephrology nurses and interdisciplinary team. Using a patient survey as a means to learn reasons why patients resist permanent access placement can be of value to the healthcare team in the development of potential strategies for interventions to reduce CVC utilization and thereby improve patient outcomes.     

Central venous catheter-related bloodstream infections: an analysis of incidence and risk factors in a cohort of 400 patients

Objective: To determine the incidence of central catheter-related bloodstream infection (CR-BSI) and to compare patient and catheter characteristics of those with and without CR-BSI from a clinically suspected subgroup. Secondly, to assess the efficacy of the acridine orange leucocyte cytospin test (AOLC) as a rapid in situ method of detecting central venous catheter (CVC) infection. Design: One-year prospective audit. Setting: Intensive care unit/high dependency unit (ICU/HDU) and general wards of a tertiary referral hospital. Patients and participants: 400 patients with non-tunnelled CVCs. Interventions: Daily surveillance, blood culture from peripheral venepuncture, blood sample from the CVC for assessment of the AOLC test and removal of suspected CVCs were carried out on patients clinically suspected of having CR-BSI. Measurements and results: CR-BSI was diagnosed using well defined criteria. Infection rate was calculated by dividing the number of definitive catheter associated infections by the total number of appropriate catheter in situ days. The AOLC test was performed on all those with suspected CR-BSI. A total of 499 CVCs in 400 patients were assessed, representing 3014 catheter in situ days. Over 80 % of patients were from our ICU/HDU, representing 404 CVCs and 1901 catheter in situ days. A total of 49/499 (9.8 %) CVCs in the same number of patients were suspected of being infected subsequently 12/499 (2.4 %) CVCs [95 % confidence interval (CI) 1.25 to 4.16] in 12 separate patients were demonstrated to be the direct cause of the patient's BSI. Rates of CR-BSI per 1000 catheter days were 3.98 (95 % CI 2.06 to 6.96) for the whole cohort and 4.20 (95 % CI 1.81 to 8.29) for the ICU/HDU subgroup. In the group suspected of having CR-BSI, CVCs were removed unnecessarily in 55 %, and no patient or catheter variables measured were predictive of the development of CR-BSI. The AOLC test was negative in all 12 catheters subsequently shown to be the definitive cause of BSI. Conclusions: We have defined the incidence of CR-BSI in a cohort of patients from a tertiary referral hospital, the rates comparing favourably with those reported for similar populations. We were unable to demonstrate significant differences in any patient or catheter variables between those with and without CR-BSI. The AOLC test used alone was unhelpful as a method to diagnose in situ CVC infection in this patient population. Received: 26 February 1998 Accepted: 30 June 1998