Management of hemodialysis catheter-related bacteremia with an adjunctive antibiotic lock solution

Relationship between Clinical Outcomes and Vascular Access Type among Hemodialysis Patients withStaphylococcus aureusBacteremia

The association between hemodialysis vascular access type, costs, and outcome of Staphylococcus aureus bacteremia (SAB) among patients with ESRD remains incompletely characterized. This study was undertaken to compare resource utilization, costs, and clinical outcomes among SAB-infected patients with ESRD by hemodialysis access type. Adjusted comparisons of costs and outcomes were based on multivariable linear regression and multivariable logistic regression models, respectively. A total of 143 hospitalized hemodialysis-dependent patients had SAB at Duke University Medical Center between July 1996 and August 2001. A total of 111 (77.6%) patients were hospitalized as a result of suspected bacteremia; 32 (22.4%) were hospitalized for other reasons. Of the 111 patients, 59.5% (n = 66) had catheters as their primary access type, 36% (n = 40) had arteriovenous (AV) grafts, and 4.5% (n = 5) had AV fistulas. Patients with fistulas were excluded from analyses because of small numbers. Patients with catheters were more likely to be white, had shorter dialysis vintage, and had higher Acute Physiology and Chronic Health Evaluation II scores compared with patients with grafts. Unadjusted 12-wk mortality did not significantly differ between patients with catheters compared with patients with grafts (22.7 versus 10.0%; P = 0.098); neither did 12-wk costs differ by access type ($22,944 +/- 18,278 versus $23,969 +/- 13,731, catheter versus graft; P > 0.05). In adjusted analyses, there was no difference in 12-wk mortality (odds ratio 1.63; 95% confidence interval 0.29 to 9.02; catheter versus graft) or 12-wk costs (means ratio 0.84; 95% confidence interval 0.60 to 1.17; catheter versus graft) among SAB-infected patients with ESRD on the basis of hemodialysis access type. Twelve-week mortality and costs that are associated with an episode of SAB are high in hemodialysis patients, regardless of vascular access type. Efforts should focus on the prevention of SAB in this high-risk group.

UNRESOLVED ISSUES IN DIALYSIS: Long-Term Management of the Tunneled Venous Catheter

Despite their propensity for significant complications, tunneled central venous catheters have become a common means of vascular access in the United States for patients requiring maintenance hemodialysis for end-stage renal disease (ESRD). Reasons for their use include advanced patient age, peripheral vascular disease (arterial and venous), late referral for creation of vascular access, and more importantly, the lack of an interdisciplinary service line on vascular access among vascular surgeons, radiologists, and nephrologists. This review article summarizes complications commonly encountered in dialysis patients who use tunneled central venous catheters for vascular access-mainly thrombosis, stenosis, and infection. Special attention is given to novel approaches for the prevention of catheter-associated infections. Effective prevention and timely treatment of common catheter-associated complications can reduce the substantial morbidity associated with the use of these devices. However, these measures should not detract from the goal of avoiding or limiting the long-term use of catheters, thereby optimizing vascular access management by ensuring the timely availability of functioning arteriovenous fistulas.

Central venous catheter-associated bloodstream infections in hemodialysis patients: Another patient safety bundle?

In a previous issue ofThe Canadian Journal of Infectious Diseases & Medical Microbiology, we reviewed the 'Safer Healthcare Now!' campaign's focus on reducing central venous catheter (CVC)-associated bloodstream infections (BSIs) as a way of improving patient safety (1). This initiative is focused on preventing CVC-associated BSIs in intensive care units. However, other patient groups are also at risk for CVC-related BSIs, suggesting that there are other individuals who would benefit from preventive efforts. A 1996 hospital-wide survey of nosocomial bacteremia in an Israeli university hospital (2) found that 9% of infected patients were on chronic hemodialysis. Surveillance in 73 hospitals in England between 1997 and 2001 found a CVC BSI rate of 21/1000 nephrology patients at risk who were hospitalized in teaching hospitals (3). This rate was similar to that found in special care neonatal units, although not quite one-half that of patients in a general intensive care unit. In a population-based survey performed in the Calgary Health Region from 2000 to 2002 (4), hemodialysis (HD) posed the greatest risk (RR 208.7; 95% CI 142.9 to 296.3) for acquiring severe BSI.

Multistate Outbreak of Listeriosis Linked to Turkey Deli Meat and Subsequent Changes in US Regulatory Policy

BACKGROUND

Data about the efficacy and tolerability of linezolid for the treatment of gram-positive bacterial infections in patients with end-stage renal disease (ESRD) are lacking.

METHODS

This retrospective case-control study compared the tolerability and efficacy of linezolid therapy for patients with ESRD and patients with non-end-stage renal disease (NESRD), all of whom had gram-positive bacterial infections.

RESULTS

There were 58 men and 33 women enrolled in the study, with a mean age of 61.5 years (range, 45.4-81.2 years). Among these patients, 28 (30.8%) were receiving hemodialysis at the start of linezolid treatment. The ESRD group had a higher percentage of patients with diabetes mellitus (57.1% vs. 33.3%; P = .029) and an older mean age (+/-SD) (72.1 +/- 10.8 years vs. 56.8 +/- 20.4 years; P < .001), compared with the NESRD group. Severe thrombocytopenia (platelet count, < 100 x 10(9) platelets/L) and anemia were significantly more frequent in the ESRD group, compared with the NESRD group (78.6% vs. 42.9% [P = .003] and 71.4% vs. 36.5% [P = .003], respectively). The independent risk factors for thrombocytopenia identified by logistic regression analysis were pretreatment disease severity score (odds ratio [OR], 1.34; 95%, confidence interval [CI], 1.13-1.60; P = .001), central catheter-related infection (OR, 4.96; 95% CI, 1.08-22.73; P = .046), and ESRD (OR, 6.14; 95% CI, 1.63-23.26; P = .007). ESRD was the only independent risk factor for anemia (OR, 4; 95% CI, 1.50-10.64; P = .006). Survival analysis for the development of thrombocytopenia or death showed significant differences between patients with ESRD and patients with NESRD (P < .001).

CONCLUSIONS

The lower tolerability of linezolid in patients with ESRD, compared with those with NESRD, is evidenced by the higher rates of thrombocytopenia and anemia in the former group. The severity of these conditions necessitates treatment discontinuation for patients with ESRD more often than for patients with NESRD.

Outcomes of tunneled femoral hemodialysis catheters: Comparison with internal jugular vein catheters

BACKGROUND

Tunneled femoral vein dialysis catheters are used as a last resort when all other options for a permanent vascular access or thoracic central vein catheter have been exhausted. There is little published literature on the complications or outcomes of tunneled femoral catheters.

METHODS

Using a prospective, computerized vascular access database, we identified all tunneled femoral dialysis catheters placed at the University of Alabama at Birmingham during a five-year period. The clinical features, catheter patency, and complications in these patients were compared to those observed in a group of sex-, age-, and date-matched control patients with tunneled internal jugular vein dialysis catheters.

RESULTS

During the study period, 27 patients received a tunneled femoral dialysis catheter, accounting for 1.9% of all tunneled catheters placed. Only 7 patients (26%) were able to convert to a new permanent dialysis access. The primary catheter patency (time from placement to exchange) was substantially shorter for femoral catheters than for internal jugular dialysis catheters (median survival, 59 vs. >300 days, P < 0.0001). Infection-free survival was similar for both groups (P= 0.66). Seven patients with femoral catheters (or 26%) developed an ipsilateral deep vein thrombosis, but catheter use was possible with anticoagulation.

CONCLUSION

Tunneled femoral dialysis catheters have a substantially shorter primary patency, but a similar risk of catheter-related bacteremia, as compared with internal jugular vein catheters. An ipsilateral lower extremity deep vein thrombosis occurs commonly after placement of a femoral dialysis catheter, but does not preclude continued catheter use.

Prolonged Stability of Stored Vancomycin, Gentamicin, and Heparin for Use in the Antibiotic-Lock Technique

The antibiotic-lock technique has been effective in salvaging tunneled catheters in hemodialysis patients with bacteremia. However, a practical concern exists with respect to the stability of the antibiotics and heparin in normal saline, when stored for a prolonged period. Vancomycin, gentamicin, and heparin were diluted in normal saline to a final concentration of 100 microg/ml of each antibiotic and 5000 units/ml heparin. Fresh samples, and samples refrigerated at 4 degrees C for 48 hours, 1 week, 2 weeks, 3 weeks, and 4 weeks, were assayed (in triplicate) for gentamicin and vancomycin concentration and bactericidal activity (Schlichter test) using methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa. An anti-Xa activity assay was used for monitoring heparin anticoagulant activity of the fresh samples and samples refrigerated for 2 and 4 weeks. Mean (+/- SD) anti-Xa activity for heparin/vancomycin solution was 7900 +/- 173 u/ml, and for heparin/gentamicin solution was 7467 +/- 751u/ml; both were stable over a 4-week storage period. Mean bactericidal titer for vancomycin was 1:121 +/- 11, and for gentamicin was 1:242 +/- 22; both were stable over a 4-week storage period. Mean vancomycin concentration was 97 +/- 4 microg/ml, and gentamicin concentration was 86 +/- 3 microg/ml; both were stable over a 4-week storage period. Vancomycin and gentamicin in a heparin/saline solution can be stored at 4 degrees C for up to 4 weeks without adversely affecting antibiotic concentration, bactericidal activity, or heparin anticoagulant activity.

Tunneled Catheters in Hemodialysis Patients: Reasons and Subsequent Outcomes

BACKGROUND

Reducing the use of tunneled catheters in hemodialysis patients requires concerted efforts to convert them to a usable permanent vascular access. The goal of this study is to evaluate the reasons for tunneled catheter use in our prevalent hemodialysis population and the success in converting them to a permanent vascular access.

METHODS

We identified all catheter-dependent hemodialysis patients at our center on a single date. These patients were followed up prospectively during a 1-year period to evaluate access procedures and conversion to permanent access use.

RESULTS

Of 458 prevalent hemodialysis patients, 108 patients (23.6%) were dialyzing through cuffed tunneled catheters: 18.5% had no further options for creation of a permanent vascular access, 28.7% had an immature access, 43.5% had access placement pending, and 9.2% had repeatedly refused access surgery. For 78 catheter-dependent patients (excluding patients with no access options and those who refused permanent access surgery), the likelihood of using a permanent access was 53% by 6 months and 80% by 1 year. In patients with an immature access, 50% were using a permanent access at 3 months, and 80%, at 6 months. Of patients with access surgery pending, 45% had access surgery performed within 3 months, and 70%, at 6 months. Finally, of all patients, the likelihood of catheter-related bacteremia was 48% at 6 months. On multivariable analysis, only duration of catheter dependence predicted subsequent use of a permanent access (hazard ratio, 3.11; 95% confidence interval, 1.70 to 5.68; P = 0.0002) for catheter dependence less than versus greater than 6 months.

CONCLUSION

Almost one quarter of our hemodialysis population is catheter dependent. Despite concerted efforts, there remain very long delays in achieving a usable permanent access, attributable to delays in both surgical access placement and access maturation. In the interim, this patient population developed a high frequency of catheter-related bacteremia.

Infections associated with medical devices: pathogenesis, management and prophylaxis

The insertion or implantation of foreign bodies has become an indispensable part in almost all fields of medicine. However, medical devices are associated with a definitive risk of bacterial and fungal infections. Foreign body-related infections (FBRIs), particularly catheter-related infections, significantly contribute to the increasing problem of nosocomial infections. While a variety of micro-organisms may be involved as pathogens, staphylococci account for the majority of FBRIs. Their ability to adhere to materials and to promote formation of a biofilm is the most important feature of their pathogenicity. This biofilm on the surface of colonised foreign bodies is regarded as the biological correlative for the clinical experience with FBRI, that is, that the host defence mechanisms often seem to be unable to handle the infection and, in particular, to eliminate the micro-organisms from the infected device. Since antibacterial chemotherapy is also frequently not able to cure these infections despite the use of antibacterials with proven in vitro activity, removal of implanted devices is often inevitable and has been standard clinical practice. However, in specific circumstances, such as infections of implanted medical devices with coagulase-negative staphylococci, a trial of salvage of the device may be justified. All FBRIs should be treated with antibacterials to which the pathogens have been shown to be susceptible. In addition to systemic antibacterial therapy, an intraluminal application of antibacterial agents, referred to as the 'antibiotic-lock' technique, should be considered to circumvent the need for removal, especially in patients with implanted long-term catheters. To reduce the incidence of intravascular catheter-related bloodstream infections, specific guidelines comprising both technological and nontechnological strategies for prevention have been established. Quality assurance, continuing education, choice of the catheter insertion site, hand hygiene and aseptic techniques are aspects of particular interest. Furthermore, all steps in the pathogenesis of biofilm formation may represent targets against which prevention strategies may be directed. Alteration of the foreign body material surface may lead to a change in specific and nonspecific interactions with micro-organisms and, thus, to a reduced microbial adherence. Medical devices made out of a material that would be antiadhesive or at least colonisation resistant would be the most suitable candidates to avoid colonisation and subsequent infection. Another concept for the prevention of FBRIs involves the impregnation of devices with various substances such as antibacterials, antiseptics and/or metals. Finally, further studies are needed to translate the knowledge on the mechanisms of biofilm formation into applicable therapeutic and preventive strategies.

Treatment and prevention of enterococcal infections--alternative and experimental approaches

Enterococci are one of the leading types of organisms isolated from infections of hospitalised patients and the third most common cause of nosocomial bloodstream infections. They contribute significantly to patient mortality and morbidity, as well as healthcare costs. The emergence of resistance against virtually all clinically available antibiotics and the ability to transfer these resistance determinants to other pathogens demonstrates the urgency for an improved understanding of enterococcal virulence mechanisms, and the development of alternative treatment and prevention options. This article reviews new antimicrobials, vaccine targets, bacteriophage therapy, as well as treatments targeting virulence factors and biofilm, for their potential to treat and/or prevent enterococcal infections. Although clinical isolates often cause serious infections, so-called 'non-pathogenic' strains are used as therapeutics in the form of probiotics. Understanding the differences between true pathogens and beneficial commensals may help to evaluate future treatment and prophylactic options.

Antibiotic Lock Technique: A Review of the Literature

OBJECTIVE:

To review the literature on the use of the antibiotic lock technique (ALT) as a treatment option for patients with highly needed catheters.

DATA SOURCES:

MEDLINE and International Pharmaceutical Abstracts were searched (1980–August 2004). Search terms included antibiotic lock, catheter infection, and topical treatment.

STUDY SELECTION AND DATA EXTRACTION:

Articles describing use of ALT in the treatment of catheter infections in humans and studies evaluating in vitro stability of antibiotics were included.

DATA SYNTHESIS:

ALT has been used in patients with highly needed catheters, usually for parenteral nutrition, cancer chemotherapy, or dialysis. Catheters are considered highly needed when removal is not feasible or desirable due to lack of alternative injection sites for required therapy. Success rates in saving the infected catheter have been variable and may depend on the infecting organism. In addition, there are conflicting data in terms of compatibility of antibiotics with heparin solutions.

CONCLUSIONS:

Consensus appears to be that the ALT can be tried for patients with highly needed catheters when infection with coagulase-negative staphylococci is documented and no systemic signs of sepsis, such as hypotension, are evident. Most of these patients are likely to need systemic therapy as well. Infection of the catheter associated with systemic gram-negative bacteremia or fungemia will most likely require removal of the catheter to prevent systemic complications. Additional research with the ALT is warranted given unanswered questions.

Slime factor positivity in coagulase negative staphylococci isolated from nasal samples of haemodialysis patients

Polysaccharide slime seems to be the most important factor by which coagulase negative staphylococci (CNS) strains adheres and colonises catheters. The aim of this study was to determine the prevalence of slime-producing CNS strains isolated from nasal samples of patients on haemodialysis and of healthy persons as a control. Nasal cultures were performed for 131 haemodialysis patients and 56 healthy persons. CNS strains were isolated from 86 of 131 patients (72.9%), and 46 of 56 healthy persons (82.1%). Twenty-four (27.9%) of the 86 CNS strains tested in the patient group and four (8.7%) of the 46 CNS strains in the control group were slime factor positive. There was a significant difference (p<0.01) in slime production between CNS strains isolated from haemodialysis patients and from control group. The detection of slime-producing coagulase-negative staphylococcus carriage in haemodialysis patients may prevent dialysis catheter-related coagulase-negative staphylococcal infections.

Veterinary hemodialysis: advances in management and technology

Hemodialysis (HD) is a renal replacement therapy that can enable recovery of patients in acute kidney failure and prolong survival for patients with end-stage kidney failure. HD is also uniquely suited for management of refractory volume overload and removal of certain toxins from the bloodstream. Over the last decade, veterinary experience with HD has deepened and refined and its geographic availability has increased. As awareness of the usefulness and availability of dialytic therapy increases among veterinarians and pet owners and the number of veterinary dialysis facilities increases, dialytic management will become the standard of advanced care for animals with severe intractable uremia.

Treatment of catheter-related bacteraemia with an antibiotic lock protocol: effect of bacterial pathogen

BACKGROUND

The standard therapy of dialysis catheter-related bacteraemia involves both systemic antibiotics and catheter replacement. We reported recently that instillation of an antibiotic lock (highly concentrated antibiotic solution) into the catheter lumen after dialysis sessions, in conjunction with systemic antibiotics, can successfully treat many episodes of catheter-related bacteraemia without requiring catheter removal. The present study evaluated whether the likelihood of achieving a cure with this protocol depends on the type of pathogen.

METHODS

This was a historically controlled interventional study of an antibiotic lock protocol for the treatment of catheter-related bacteraemia. We analysed prospectively the likelihood of clinical cure (fever resolution and negative surveillance cultures) with an antibiotic lock protocol among patients with dialysis catheter-related bacteraemia. In addition, infection-free catheter survival was evaluated for up to 150 days, and compared with that observed among patients managed with routine catheter replacement.

RESULTS

Overall, the antibiotic lock protocol was successful in 33 of 47 infected patients (70%) with catheter-related bacteraemia. The likelihood of a clinical cure was 87% for Gram-negative infections, 75% for Staphylococcus epidermidis infections, and only 40% for Staphylococcus aureus infections (P = 0.04). The median infection-free catheter survival with the antibiotic lock protocol was longer than that observed among patients with routine catheter replacement (154 vs 71 days, P = 0.02).

CONCLUSIONS

The clinical success of an antibiotic lock protocol in eradicating catheter-related bacteraemia while salvaging the catheter is highly dependent on the bacterial pathogen. Thus, the overall success rate in an individual dialysis programme will depend on the relative frequencies of different bacterial pathogens.

Prevention of dialysis catheter-related sepsis with a citrate-taurolidine-containing lock solution

BACKGROUND

The use of haemodialysis catheters is complicated by catheter-related sepsis. Intraluminal colonization of the catheter with bacteria is important in the pathogenesis of catheter-related sepsis. The use of a catheter lock solution containing the antimicrobial taurolidine might prevent bacterial colonization, thereby reducing the incidence of catheter-related sepsis.

METHODS

In a randomized prospective trial, patients receiving a dialysis catheter were included and catheters were locked with either heparin or a citrate-taurolidine-containing solution. Blood cultures drawn from the catheter lumen were routinely taken every 2 weeks and at time of removal of the catheter to detect bacterial colonization. Catheter-related sepsis and exit-site infections were registered for both groups.

RESULTS

A total of 76 catheters were inserted in 58 patients. The incidence of catheter colonization progressed slowly over time with no differences between dialysis catheters filled with heparin or citrate-taurolidine-containing solution. The number of exit-site infections was also similar between both groups. In the heparin group, four cases of catheter-related sepsis occurred as opposed to no sepsis episodes in the patients with catheters locked with the citrate-taurolidine-containing solution (P<0.5). No side effects with the use of citrate-taurolidine catheter lock solution were noted.

CONCLUSIONS

This study shows that catheter filling with a solution containing the antimicrobial taurolidine may significantly reduce the incidence of catheter-related sepsis. Taurolidine appears to be effective and safe and does not carry the risk for side effects that have been reported for other antimicrobial lock solutions containing gentamicin or high concentrations of citrate.

Comparison of Arteriovenous Grafts in the Thigh and Upper Extremities in Hemodialysis Patients

ABSTRACT. Placement of a thigh graft is an option in hemodialysis patients who have exhausted all upper extremity sites for permanent vascular access. The outcome of thigh grafts has been reported only in retrospective studies. The outcomes of 409 grafts placed at a single institution during a 3.5-yr period were evaluated prospectively, including 63 thigh grafts (15% of the total). Information was recorded on surgical complications, dates of radiologic and surgical interventions, and date of graft failure. The technical failure rate was approximately twice as high for thigh grafts, as compared with upper extremity grafts (12.7versus5.8%;P= 0.046). Intervention-free survival was similar for thigh and upper extremity grafts (median, 3.9versus3.5 mo;P= 0.55). Thrombosis-free survival was also comparable for thigh and upper extremity grafts (median, 5.7versus5.5 mo;P= 0.94). Cumulative survival (time to permanent failure) was similar for thigh and upper extremity grafts (median, 14.8versus20.8 mo;P= 0.62). When technical failures were excluded, the median cumulative survival was 27.6 mo for thigh grafts and 22.5 mo for upper extremity grafts (P= 0.72). The frequency of angioplasty (0.28versus0.57 per year), thrombectomy (1.58versus0.94 per year), surgical revision (0.28versus0.18 per year), and total intervention rate (2.15versus1.70 per year) was similar between thigh and upper extremity grafts. Access loss as a result of infection tended to be higher for thigh grafts than for upper extremity grafts (11.1versus5.2%;P= 0.07). In conclusion, placement of thigh grafts should be considered a viable option among hemodialysis patients who have exhausted all options for a permanent vascular access in both upper extremities. E-mail mdallon@uab.edu

Ethanol-lock technique in the treatment of bloodstream infections in pediatric oncology patients with broviac catheter

PURPOSE

To assess the ethanol-lock technique as a means of treating central venous line infections. Bloodstream infections in patients with tunneled central venous catheters can lead to removal of the lines.

METHODS

Twenty-eight children and adolescents aged 2 to 18 years, with different types of cancer, had Broviac catheters and presented with positive blood culture and clinical signs of infection between January 2000 and December 2001. The ethanol-lock technique was performed 24 times in 18 patients in addition to empiric (initially) and specific (after antibiogram) intravenous antibiotic treatment. In another 15 cases, 13 children were treated with systemic antibiotics alone.

RESULTS

Sixty-seven percent of the patients treated with ethanol locks had no infectious relapse of any kind within 4 weeks of treatment or during subsequent aplasia, compared with 47% treated with systemic antibiotics alone. In one boy the catheter infection could not be cleared with systemic antibiotics alone, but after one course of ethanol locks no more blood culture-positive infectious episodes were observed. No severe clinical side effects of ethanol flush were observed. Mild symptoms that occurred were tiredness, headaches, dizziness, nausea, and light-headedness.

CONCLUSIONS

The ethanol-lock technique appears to be a safe, well tolerated, and effective way to treat central venous line infections, even in small children. A prospective randomized study should be designed to compare antibiotic-lock, ethanol-lock technique, and systemic antibiotics alone in the treatment of device-associated bloodstream infection.

Prophylaxis against dialysis catheter-related bacteremia with a novel antimicrobial lock solution

Catheter-related bacteremia, a frequent complication in patients who are undergoing hemodialysis, may be prevented by eradication of the catheter biofilm. Catheter lock solution (CLS) is an investigational preparation containing taurolidine, a biocompatible antimicrobial agent, and citrate, an anticoagulant agent. CLS was instilled into the catheter lumens after each dialysis session for 20 catheter-dependent hemodialysis patients. Catheter outcomes were compared with those observed in 30 concurrent control patients whose catheters were instilled with heparin. Bacteremia-free survival at 90 days was higher among patients who received CLS than among control patients who received heparin (94% vs. 47%; P<.001). Unassisted catheter patency (without tissue plasminogen activator instillation) was lower among patients who received CLS than among control patients (32% vs. 76%; P<.001). CLS dramatically reduces the frequency of catheter-related bacteremia among patients undergoing hemodialysis, although there is an increased requirement for thrombolytic interventions to maintain catheter patency.

Vascular and cardiac infections in end-stage renal disease

Patients with end-stage renal disease (ESRD) receiving hemodialysis (HD) are vulnerable to intravascular and endocardial infections. These include vascular access infections, vascular stent infections, and bacterial endocarditis. Staphylococcus aureus is the most commonly encountered microorganism in these conditions. Prolonged intravenous antibiotic therapy is often indicated in these infections. Surgical removal of the infected vascular access or stent may be required. Infective endocarditis occurs less frequently in renal transplant recipients than in patients on HD. Although bacterial endocarditis may occur, fungal endocarditis with organisms such as Aspergillus and Candida species occurs with disproportionately high frequency among renal transplant recipients because of immunosuppression. Prolonged intravenous antibiotic or antifungal therapy is indicated, and valve replacement is often necessary.

Antibiotic lock-technique for the treatment of catheter-related bloodstream infections

The management of central venous catheter-related bloodstream infections (CRBSI), though still debated, requires the removal of the line in most cases: we investigated the efficacy of an alternative approach, based on higher concentrations of antibiotics locked within the catheter lumen, in an open, pilot study aimed at preserving the line in place and at eradicating the infection. Thirty consecutive patients carrying a central line over 10 days and who fulfilled criteria for ascertained diagnosis of bacterial CRBSI, had the catheter "locked" with antimicrobials therein; all patients also received systemic antibiotic therapy within the first 48 hours. Subsequently, 15 patients underwent locks alone, and 15 locks plus systemic therapy. Twenty-eight out of 30 (93.3%) patients retained the catheter in place, appearing to be cleared of infection and no treatment-related untoward events were observed. Locks should be considered as effective as line removal in the management of bacterial CRBSI in unselected patients, and could thus provide advantages in terms of resource sparing and lowered antibiotic pressure in the hospital setting.

Infection with antimicrobial-resistant microorganisms in dialysis patients

The prevalence of antimicrobial-resistant microorganisms in various health care settings, including outpatient dialysis facilities, has increased dramatically in the last decade. Antimicrobial use and patient-to-patient transmission of resistant strains are the two main factors that have contributed to this rapid increase. Methicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative staphylococci are commonly isolated as a cause of hemodialysis (HD) catheter-related bacteremia and peritoneal dialysis (PD)-related catheter infection and peritonitis. The widespread use of vancomycin in dialysis patients is of concern because of an increase in the prevalence of vancomycin-resistant enterococci (VRE) in dialysis patients. Staphylococci with reduced sensitivity to vancomycin have also appeared in dialysis patients. A more recent problem is the appearance of S. aureus isolates with a high degree of resistance to the topical antimicrobial agent mupirocin. This has been seen in PD patients who have received prophylactic application of mupirocin at the peritoneal catheter exit site. Appropriate antimicrobial use will help protect the efficacy of currently used antibiotics, such as vancomycin. Published guidelines for use of vancomycin should be followed. New antimicrobials such as linezolid and quinupristin/dalfopristin have activity against VRE and MRSA, but resistance to these agents has already occurred. Preventing transmission of antimicrobial-resistant microorganisms in health care settings, including outpatient dialysis facilities, is important in limiting the spread of these resistant organisms.

Hemodialysis infection prevention with polysporin ointment

Hemodialysis patients in whom permanent vascular access cannot be achieved are dependent on a central venous catheter. In such patients, catheter-related infections are a common and serious complication. This study was a randomized clinical trial to determine if topical Polysporin Triple antibiotic ointment applied to the central venous catheter insertion site could reduce the incidence of catheter-related infections. A total of 169 patients receiving hemodialysis through a central venous catheter were randomized to receive Polysporin Triple or placebo using a double-blind study design. In the 6-mo study period, infections were observed in more patients in the placebo group than in the Polysporin Triple group (34 versus 12%; relative risk, 0.35; 95% CI, 0.18 to 0.68; P = 0.0013). The number of infections per 1000 catheter days (4.10 versus 1.02; P < 0.0001) and the number of bacteremias per 1000 catheter days (2.48 versus 0.63; P = 0.0004) were also greater in the placebo group. Within the 6-mo study period, there were 13 deaths in the placebo group as compared with 3 deaths in the Polysporin Triple group (P = 0.0041). When all available follow-up information was included, the difference in survival remained significant (19 versus 9 deaths; P = 0.0027). Within the first 6 mo, infections were observed in 7 of the 13 placebo subjects who died (54%) as compared with no infections in the three Polysporin Triple subjects who died. The prophylactic application of topical Polysporin Triple antibiotic ointment to the central venous catheter insertion site reduced the rate of infections and was associated with improved survival in hemodialysis patients.

Treatment approaches for infected hemodialysis vascular catheters

PURPOSE OF REVIEW

The focus of the review is to delineate protocols for catheter removal, catheter replacement and duration of therapy when a catheter-related infection occurs, and to demonstrate possible means of preventing such infections.

RECENT FINDINGS

The evidence supporting these views will be discussed in the light of our current practice.

SUMMARY

Cuffed tunneled hemodialysis catheters have evolved for wide use as both temporary and semi-permanent hemodialysis access. The primary barriers to long-term catheter use are catheter-related infection and catheter dysfunction. Catheter-related infection has emerged as the primary barrier to long-term catheter use. Under both circumstances, however, catheter replacement or some form of intervention is often needed. Because of this, catheters are often removed and replaced, but the duration of therapy and the timing of replacement of these catheters is not completely clear.

Biofilms and infection in dialysis patients

Biofilm bacterial infections are implicated in most human bacterial infections and are also common in patients undergoing treatment with hemodialysis and peritoneal dialysis. Skin bacteria, which grow into microcolonies with biofilm formation in dialysis environments, are implicated in most of these infections. Dissemination of bacterial biofilms in hemodialysis patients induces bacteremia and endotoxemia. In peritoneal dialysis patients, biofilm causes peritonitis and catheter-related infections with consequent loss of catheters and technique failure. Effective strategies for the diagnosis, intervention, and prevention of biofilm-related infections in dialysis patients are described in this review.