Central Venous Catheter Colonization Research Articles

Colonization of central venous catheter in the intensive care units at the Institute of Cardiovascular Disease "Dedinje": One year study

The application of Central Venous Catheters (CVC) is associated with increased risk of microbial colonization and infection. The aim of present study was to assess the frequency of pathogens colonizing CVC and to determine their susceptibility pattern to various antimicrobial agents. A total of 253 samples of CVC from intensive care units (ICU) patients were received for culture during 2003. All microorganisms were identified by standard microbiological methods and the susceptibility to antimicrobial agents was determined according to NCCLS recommendations. A total of 184 (72.7%) cultures were positive and 223 pathogens were isolated. Coagulase negative staphylococci (CNS) were the dominant isolates (24.7%), followed by Enterobacter spp. (12.1%), Pseudomonas spp. (11.7%), Enterococcus spp. (9.9%), Klebsiella spp. (8.6%), Candida spp. (7.6%), Acinetobacter spp. (7.6%), other Gram negative nonfermentative bacilli (5.8%), Serratia spp. (4.5%), Staphylococcus aureus (2.6%), Proteus mirabilis (2.2%), E. coli (1.8%) and Citrobacter spp. (0.9%). Meropenem (84.5%) and vancomycin (100%) remain the most effective antimicrobial agents against Gram negative and Gram positive bacteria, respectively. Gram negative bacilli and CNS are the commonest microorganisms colonizing CVC from ICU patients. The increasing resistance of the bacteria to antimicrobial agents is the major problem in spite of restricted policy of using antimicrobial agents in ICU.

The incidence of infectious complications of central venous catheters at the subclavian, internal jugular, and femoral sites in an intensive care unit population*

The objective was to assess the risk of central venous catheter infection with respect to the site of insertion in an intensive care unit population. The subclavian, internal jugular, and femoral sites were studied. An epidemiologic, prospective, observational study. The setting is a well-functioning intensive care unit under a unified critical care medicine division in a university teaching hospital. Critical care medicine attendings and fellows covered on site 17 and 24 hrs per day, respectively. Patients were critically ill. All patients were triaged into the intensive care unit by on-site critical care medicine fellows. None. In an intensive care unit population, we prospectively studied the incidence of central venous catheter infection and colonization at the subclavian, internal jugular, and femoral sites. The optimal insertion site for each individual patient was selected by experienced intensive care physicians (critical care medicine attendings and fellows). All of the operators were proficient in inserting catheters at all three sites. Confounding factors were eliminated; there were a limited number of experienced operators inserting the catheters, a uniform protocol stressing strict sterile insertion was enforced, and standardized continuous catheter care was provided by dedicated intensive care nurses proficient in all aspects of central venous catheter care. Two groups of patients were analyzed. Group 1 was patients with one catheter at one site, and group 2 was patients with catheters at multiple sites. Group 1 was the primary analysis, whereas group 2 was supporting.A total of 831 central venous catheters and 4,735 catheter days in 657 patients were studied. The incidence of catheter infection (4.01/1,000 catheter days, 2.29% catheters) and colonization (5.07/1,000 catheter days, 2.89% catheters) was low overall. In group 1, the incidence of infection was subclavian: 0.881 infections/1,000 catheter days (0.45%), internal jugular: 0/1,000 (0%), and femoral: 2.98/1,000 (1.44%; p = .2635). The incidence of colonization was subclavian: 0.881 colonization/1,000 catheter days (0.45%), internal jugular: 2.00/1,000 (1.05%), and femoral: 5.96/1,000 (2.88%, p = .1338). There was no statistically significant difference in the incidence of infection and colonization or duration of catheters (p = .8907) among the insertion sites. In group 2, there was also no statistically significant difference in the incidence of infection and colonization among the three insertion sites. In an intensive care unit population, the incidence of central venous catheter infection and colonization is low overall and, clinically and statistically, is not different at all three sites when optimal insertion sites are selected, experienced operators insert the catheters, strict sterile technique is present, and trained intensive care unit nursing staff perform catheter care.

Reduced colonization and infection with miconazole–rifampicin modified central venous catheters: a randomized controlled clinical trial

Central venous catheters (CVC) are a major cause of nosocomial bloodstream infections. Catheters modified with miconazole and rifampicin that constantly and slowly release antimicrobial substances are assumed to be beneficial in reducing rates of colonization and catheter-related infections. Prospective controlled non-blinded randomized clinical trial in two German university hospitals. 223 adult inpatients with CVC between October 2000 and February 2002. Baseline characteristics, APACHE II score and therapeutic interventions were comparable. Randomization to receive either a miconazole and rifampicin modified catheter (n=118) or a standard triple-lumen CVC (n=105). MEASUREMENTS, DEFINITIONS: Microbiological evaluation was done after CVC removal. A catheter was considered colonized if growth of > or =15 cfu was found by semi-quantitative roll-plate technique from a proximal or distal catheter segment. A catheter-related infection (CRI) was defined as a colonized catheter with local signs of inflammation. A catheter-related bloodstream infection (CR-BSI) was defined as a colonized catheter with isolation of the same organism from the patient's blood with accompanying clinical signs of infection. A colonization of CVC was observed in six patients (5.1%) with a modified catheter and 38 patients (36.2%) with a standard catheter (P < 0.001). Five patients in the modified group (4.2%) and 18 in the standard group (17.1%) developed CRI (P=0.002). One assumed CR-BSI was detected in the standard group, with none in the modified group. No adverse effects related to the modified catheters and no antimicrobial resistance were observed. CVC supersaturated with miconazole and rifampicin were associated with a significantly lower risk for catheter colonization and catheter-related infections compared to standard catheters.

Moraxella osloensis Blood and Catheter Infections During Anticancer Chemotherapy: Clinical and Microbiologic Studies of 10 Cases

Moraxella osloensis, a gram-negative bacterium that is saprophytic on skin and mucosa, rarely causes infections. Moreover, infections in patients with cancer have not been reported. We describe 10 cases of M. osloensis blood or catheter infections that occurred during anticancer chemotherapy with or without preexisting neutropenia. The organism was identified definitively by sequencing analysis of the 16S ribosomal RNA gene. Fever (up to 39.7 degrees C) with substantial neutrophilia characterized these infections. The infections were monomicrobic for 3 patients and polymicrobic for 7 patients. Nine patients acquired the infection through central venous catheter colonization. The likely sources of the organism were sinusitis (3 cases), bronchitis (1 case), presumed subclinical mucositis from anticancer therapy (4 cases), and cutaneous graft-vs-host disease (2 cases). The infections resolved, without catheter removal, after antibiotic therapy with cell wall-active agents, to which all strains were shown to be susceptible. The M. osloensis strains exhibited significant morphologic variations on gram stain, and sheep blood agar was the preferred culture medium for 9 strains.

Moraxella osloensisBlood and Catheter Infections During Anticancer Chemotherapy

Moraxella osloensis, a gram-negative bacterium that is saprophytic on skin and mucosa, rarely causes infections. Moreover, infections in patients with cancer have not been reported. We describe 10 cases of M osloensis blood or catheter infections that occurred during anticancer chemotherapy with or without preexisting neutropenia. The organism was identified definitively by sequencing analysis of the 16S ribosomal RNA gene. Fever (up to 39.7°C) with substantial neutrophilia characterized these infections. The infections were monomicrobic for 3 patients and polymicrobic for 7 patients. Nine patients acquired the infection through central venous catheter colonization. The likely sources of the organism were sinusitis (3 cases), bronchitis (1 case), presumed subclinical mucositis from anticancer therapy (4 cases), and cutaneous graft-vs-host disease (2 cases). The infections resolved, without catheter removal, after antibiotic therapy with cell wall–active agents, to which all strains were shown to be susceptible. The M osloensis strains exhibited significant morphologic variations on Gram stain, and sheep blood agar was the preferred culture medium for 9 strains.

Risk of colonization of central venous catheters: Catheters for total parenteral nutrition vs. other catheters.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Julie Eddins, J Dimick, S Swoboda, M Talamini, R Pelz, C Hendrix, P Lipsett; Risk of colonization of central venous catheters: Catheters for total parenteral nutrition vs. other catheters.. Journal of the Association for Vascular Access 1 March 2004; 9 (1): 48–49. doi: https://doi.org/10.2309/1552-8855-9.1.48 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest Search

A continuous quality-improvement program reduces nosocomial infection rates in the ICU.

To assess the impact of a continuous quality-improvement program on nosocomial infection rates. Prospective single-center study in the medical-surgical ICU of a tertiary care center. PATIENTS. We admitted 1764 patients during the 5-year study period (1995-2000); 55% were mechanically ventilated and 21% died. Mean SAPS II was 37+/-21 points and mean length of ICU stay was 9.7+/-16.1 days. Implementation of an infection control program based on international recommendations. The program was updated regularly according to infection and colonization rates and reports in the literature. Prospective surveillance showed the following rates per 1000 procedure days: ventilator-associated pneumonia (VAP) 8.7, urinary tract infection (UTI) 17.2, central venous catheter (CVC) colonization 6.1, and CVC-related bacteremia and 2.0; arterial catheter colonization did not occur. In the 5 years following implementation of the infection control program there was a significant decline in the rate per patient days of UTI, CVC colonization, and CVC-related bacteremia but not VAP. Between the first and second 2.5-year periods the time to infection increased significantly for UTI and CVC-related colonization. A continuous quality-improvement program based on surveillance of nosocomial infections in a nonselected medical-surgical ICU population was associated with sustained decreases in UTI and CVC-related infections.

Risk of Colonization of Central Venous Catheters: Catheters for Total Parenteral Nutrition Vs Other Catheters

Infected central venous catheters cause morbidity and mortality. To compare the risk for colonization of central venous catheters used for total parenteral nutrition with that of catheters used for other purposes. Retrospective review of prospectively acquired data on 260 patients with a stay in a surgical intensive care unit longer than 3 days. Single-lumen catheters used solely for total parenteral nutrition were inserted into the subclavian vein and cared for by a dedicated team. Catheters for other purposes were placed and cared for by other staff. Catheters were cultured if clinical findings suggested infection. Of 854 central venous catheters, 61 (7%) were used for total parenteral nutrition. During 4712 catheter days of observation, 89 catheters of all types were colonized. Risk factors for colonization included duration of catheterization (P < .001), having 3 or more lumens (hazard ratio, 1.7; 95% CI, 1.1-2.6), pulmonary artery catheterization (hazard ratio, 1.7; 95% CI, 1.1-2.7), and placement in the internal jugular vein (hazard ratio, 1.6; 95% CI, 1.1-2.5). Catheters used for total parenteral nutrition (hazard ratio, 0.14; 95% CI, 0.04-0.57) and those in the subclavian vein (hazard ratio, 0.51; 95% CI, 0.3-0.8) were at lower risk of colonization. In a multivariate Cox model, the only significant factor was a 5-fold lower risk of infection for catheters used for total parenteral nutrition (hazard ratio, 0.19; 95% CI, 0.04-0.83). Rates of colonization were lowest for catheters used solely for total parenteral nutrition, suggesting that a team approach improves patients' care.

Bacterial colonisation of midline and central venous catheters

The provision of parenteral nutrition conventionally requires the insertion of a central venous catheter (CVC) with the attendant risks of pneumothorax, vascular damage and line sepsis [1]. In addition, CVC insertion requires appropriately trained medical staff. It is possible to provide central venous access with peripherally inserted central catheters (PICC) but these are associated with malposition, catheter fracture, leakage and occlusion [2]. An alternative to these is the use of 20 cm single lumen 22 G venous catheters inserted in the antecubital fossa (midlines). This unit provides a 'midline' service for parental nutrition or long-term venous access, and this audit describes the experience of this service to date. All lines were inserted on a general ward by a trained theatre technician using standard sterile techniques including chlorhexidine or iodine (in 70% methylated spirit) skin preparation and a semipermeable film dressing (tegaderm™). At removal, midline tips were sent for microbiological analysis using a Maki roll technique. There were 160 midlines inserted over an 18 month period, 139 catheters were inserted for parental nutrition and 21 for other reasons. Catheters remained in situ for median of 6 days with a range of 1–60 days. Reasons for catheter removal included blockage (13%), concerns over arm swelling (17.5%) and completion of therapy (39%). Of the 160 midlines inserted, microbiological data were available on 120. There was an overall bacterial colonisation rate of 20.8%. By comparison the colonisation rate for CVC in this unit is 49%. The colonisation rates for midlines and CVCs become significantly different by day 7 (P = 0.03, χ2) and remain so thereafter. For midlines, the majority of catheters that eventually become colonised do so by day 8. In contrast, for CVCs the colonisation rate continues to rise until day 15. The majority of organisms isolated from midline catheters were staphylococcus epidermidis (19/27). Other organisms included β-haemolytic streptococcus (two cases), enterobacter aerogenese (two cases), MRSA (one case), coliform (one case), staphylococcus aureus (one case) and candida (one case). Midline catheters represent a simple technique that can be performed by nonmedical staff. They can be used for long-term intravenous access with a lower risk of colonisation than central venous catheters.

Antifungal activity of amphotericin B, fluconazole, and voriconazole in an in vitro model of Candida catheter-related bloodstream infection.

The activity of five simulated antifungal regimens for eradication of catheter-related bloodstream Candida infection was evaluated with an in vitro pharmacodynamic model. Single-lumen central venous catheters were colonized with Candida species by sequentially incubating central venous catheters in plasma and then in growth medium (RPMI plus morpholinepropanesulfonic acid) containing a standardized suspension (10(5) CFU/ml) of Candida albicans, Candida glabrata, or slime-producing Candida parapsilosis. Colonized central venous catheters were then placed in a one-compartment pharmacodynamic model where five antifungal regimens (plus control) were simulated: amphotericin B, 1.0 mg/kg every 24 h; amphotericin B, 0.5 mg/kg every 24 h; fluconazole, 400 mg every 24 h; fluconazole, 800 mg every 24 h; and voriconazole, 4 mg/kg every 12 h. During exposure to the simulated clinical regimens, samples were serially removed from the model over 48 h for quantitation of viable organisms. All antifungal regimens suppressed fungal counts by both peripheral and catheter sampling versus control (P = 0.001). Overall, antifungal activity ranked amphotericin B (1 mg/kg) > amphotericin B (0.5 mg/kg) > or = voriconazole > fluconazole (800 mg) > or = fluconazole (400 mg). No regimen, however, completely eradicated (by culture and electron microscopy) central venous catheter colonization. Regrowth was noted in the model during therapy against C. glabrata and C. parapsilosis but was not associated with an increase in the MICs for the isolates. Lack of in vitro antifungal activity against biofilm-encased organisms appeared to be the primary reason for mycological failure of antifungal regimens in the model.

Use of antibiotic locks to treat colonized central venous catheters.

Infections that result from bacterial colonization of central venous catheters are a significant problem in modern healthcare. The most effective means of eradication of such infections is the removal of colonized lines, but line removal carries drawbacks of its own and in many cases the balance of risks favours treatment in situ. Systemic antibiotics are usually administered but these frequently fail to achieve sterilization, and accordingly attention has turned to intraluminal therapy using antibiotic locks, in which 1-2 mL of a concentrated antibiotic solution is instilled to fill the lumen, left for a predetermined period, and removed. The evidence in favour of this technique is anecdotal and should not be allowed to influence any decision about line removal, but is sufficiently encouraging to justify the use of locks when in situ treatment is deemed acceptable. Indications, agents and appropriate administration regimes are discussed.

Impact of bloodstream infection on outcomes among infected surgical inpatients.

To assess the importance of bloodstream infection (BSI) to outcomes among infected surgical patients. Bloodstream infection complicating infection is thought to connote a more serious condition compared with a primary infection alone. The authors recently reported, however, that BSI does not alter outcomes with central venous catheter colonization in the presence of sepsis. The significance of BSI with other infections has been incompletely evaluated. Data on all episodes of infection among surgical patients were collected prospectively during a 38-month period at a single hospital, then analyzed retrospectively to determine the independent prognostic value of BSI for all infections by logistic regression analysis, and for abdominal infections and pneumonia using matched control groups. During the study period, 2,076 episodes of infection occurred, including 363 with BSI. Patients with BSI had a greater severity of illness and a greater death rate. After logistic regression, however, BSI did not independently predict death. After matching patients with abdominal infections and pneumonia with BSI to patients without BSI but with a similar site of infection, severity of illness, age, and causative organism, no difference in outcome was seen. Bloodstream infection is associated with critical illness and death but appears to be a marker of severe primary disease rather than an independent predictor of outcome.

Factores de riesgo asociados a colonización y bacteriemia en catéteres venosos centrales no tunelizados

To identify risk factors for colonization and bacteremia among patients with non-tunnelled central venous catheters. A prospective study was conducted of a cohort of patients carrying non-tunnelled central venous catheters. Different parameters were obtained and the degree of its association with colonization of the distal portion of the catheter or with bacteremia associated with colonization was estimated. The CDC (centers for Disease Control) diagnostic criteria of colonization and catheter-related bacteremia were used. A total of 118 catheters were eventually analyzed, corresponding to 114 patients, with a catheterization mean time of 14 +/- 8 days (mean +/- SD); out of these 114 patients, 51 were colonized and in 22 the presence of associated bacteremia was confirmed. The parameters associated with a higher risk for catheter colonization included length of colonization, femoral location, number of lumina and a vital prognosis lower than one month. All these factors, with the exception of the increase in the number of lumina, showed an independent association with colonization on the multivariate analysis [catheterization length (in weeks): OR 1.46; 95% CI: 1.0-2.11; femoral location: OR 3.73; 95% CI: 1.16-11.9; vital prognosis lower than one month: OR 12.7; 95% CI: 1.4-112.7]. As for risk for catheter-related bacteremia, the univariate analysis showed an association with catheterization length and a vital prognosis lower than one month; the latter was the only factor that maintained an independent association in the multivariate analysis (OR 5.75; 95% CI: 1.17-28.27). The present study documents the relevance of prolonged catheterization as a consistent risk for colonization of non-tunnelled central venous catheters. This risk increases independently in canalization at femoral site and particularly among severely ill patients. The presence of these factors allows the identification of a high risk population for the development of catheter related bacteremia.

A prospective, randomized, controlled trial comparing transparent polyurethane and hydrocolloid dressings for central venous catheters

Background: This study was undertaken to determine the frequency of skin colonization, hub colonization, and central venous catheter colonization in transparent hydrocolloid versus standard polyurethane dressings. Methods: Adult patients requiring the insertion of a multilumen central venous catheter in an intensive care unit were randomized to receive either a standard polyurethane dressing or a transparent hydrocolloid dressing. Cultures were obtained from 125 skin insertion sites, 141 catheter hubs, 128 catheter tips, and blood samples from 132 patients. Extensive data on patient and catheter characteristics were collected. Results: Skin and hub cultures revealed no significant difference in degree of colonization. However, the hydrocolloid group had a significantly higher level of catheter colonization than the polyurethane group ( P = .048). Conversely, there was a significantly higher frequency of positive blood cultures in the polyurethane group ( P = .03), although the majority were considered to be potential contaminants. There were only 6 cases in which the same species was simultaneously isolated from a positive blood culture and a colonized catheter, 5 from the hydrocolloid group and 1 from the polyurethane group. Conclusions: The results of this study suggest that an increased risk of catheter colonization is associated with the use of hydrocolloid dressings, despite previous research suggesting that they significantly reduce microbial growth compared with standard polyurethane. The clinical significance of increased numbers of positive blood cultures in the polyurethane group requires further examination, although distinguishing between contamination and true infection in intensive care settings continues to be methodologically challenging. Further studies are required to determine whether these findings are generalizable across different study settings and whether similar outcomes are obtained when different brands of hydrocolloid dressing are used. (AJIC Am J Infect Control 1999;27:488-96)

Preventing central venous catheter-related infection in a surgical intensive-care unit.

The cumulative effect of five measures (introduction of hand disinfection with alcohol, a new type of dressing, a one-bag system for parenteral nutrition, a new intravenous connection device, and surveillance by an infection control practitioner) on central venous catheter colonization and bacteremia was studied. Colonization was significantly reduced (P<.025); the decrease in bacteremia was not statistically significant.

Decreasing Catheter Colonization Through the Use of an Antiseptic-Impregnated Catheter: A Continuous Quality Improvement Project

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. Prospective, randomized, controlled (phase I); prospective, concurrent data collection (phase II). Tertiary referral hospital with level 1 trauma center. 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). 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. 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. 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.

Benefit of Heparin in Central Venous and Pulmonary Artery Catheters: A Meta-analysis of Randomized Controlled Trials

To evaluate the effect of heparin on thrombus formation and infection associated with use of central venous and pulmonary artery catheters. We used MEDLINE, EMBASE, citation review of relevant primary and review articles, personal files, and contact with expert informants. Fourteen randomized controlled trials evaluating prophylactic doses of heparin or heparin bonding were included. In duplicate, independently, we abstracted data on the population, intervention, outcome, and methodologic quality. Prophylactic heparin decreases catheter-related venous thrombosis (relative risk [RR], 0.43; 95% confidence interval [CI], 0.23, 0.78) and bacterial colonization (RR, 0.18; 95% CI, 0.06, 0.60) of central venous catheters and may decrease catheter-related bacteremia (RR, 0.26; 95% CI, 0.07, 1.03). Heparin bonding decreases the risk of pulmonary artery catheter clot formation within 24 h (RR, 0.08; 95% CI, 0.02, 0.37). Heparin administration effectively reduces thrombus formation and may reduce catheter-related infections in patients who have central venous and pulmonary artery catheters in place. Cost-effectiveness comparisons of unfractionated heparin, low molecular weight heparin, and warfarin are needed.

Bacterial colonization and peripheral bacteraemia associated with central venous haemodialysis catheters: A cross‐sectional study

Summary: Septicaemia related to internal luminal colonization of central venous catheters has been described in many clinical settings including haemodialysis. the prevalence and consequence of intraluminal colonization of central venous haemodialysis catheters is unknown. A cross‐sectional study of asymptomatic patients receiving haemodialysis through central venous catheters was performed. Differential (central line and peripheral) quantitative blood cultures were taken on three occasions. Twenty‐one patients were studied and 20 had colonized central venous catheters. the organisms isolated were Coagulase negative Staphylococci (16 cases), Bacillus species (three), Corynebacterium (three), Pseudomonas species (three), and others (three). Fifteen patients also had significant peripheral bacteraemia associated with the same organism that was cultured from their central line. Seven patients had septic episodes associated with these same organisms. Swabs taken of the internal catheter surfaces also cultured these organisms. the vast majority (95%) of central venous haemodialysis catheters are colonized by bacteria. Seventy‐six per cent have associated peripheral bacteraemia, which can lead to systemic infection.

Endoluminal brushing for detection of central venous catheter colonization—a comparison of daily vs. single brushing on removal

The fibrin assay system (FAS) has been designed to address the problem of in-situ diagnosis of central venous catheter (CVC) colonization. The FAS was evaluated in 12 critically ill patients with daily brushings, comparing results with culture of the catheter tip and blood. Data analysis of the FAS showed a sensitivity of 0 with a specificity of 1·0. The study was repeated in a further 12 high-risk patients with a single terminal brushing on catheter removal. This gave a sensitivity of 0·14 and a specificity of 0·8. Differences in sensitivity may be due to daily disruption of the endolummal fibrin clot. Our results do not support the routine use of the FAS to detect CVC colonization in the intensive care unit.

Antiseptic-impregnated central venous catheters reduce the incidence of bacterial colonization and associated infection in immunocompromised transplant patients

The incidence of bacterial colonization of central venous catheters using a standard polyurethane catheter was compared with that using an antiseptic (silver sulphadiazine and chlorhexidine) impregnated catheter in a group of patients with thoracic organ transplantation. Colonization was reduced from 25 of 35 standard catheters to 10 of 44 study catheters (P<0.002), a 68% reduction. Similarly, the incidence of concomitant infection, by the same organism at another site was reduced from 10 of 35 standard catheters to 4 of 44 study catheters (P<0.03), a 63% reduction.