Treatment of dialysis catheter-related Staphylococcus aureus bacteremia with an antibiotic lock: a quality improvement report

Salvage strategy for long-term central venous catheter-associated Staphylococcus aureus infections in children: a multi-centre retrospective study in France

OBJECTIVES

Catheter removal is recommended in adults with Staphylococcus aureus central-line-associated bloodstream infection (CLABSI) but is controversial in children with long-term central venous catheters (LTCVC). We evaluated the occurrence of catheter salvage strategy (CSS) in children with S. aureus LTCVC-associated CLABSI and assessed determinants of CSS failure.

METHODS

We retrospectively included children (<18 years) with an LTCVC and hospitalized with S. aureus CLABSI in eight French tertiary-care hospitals (2010-2018). CSS was defined as an LTCVC left in place ≥72 h after initiating empiric antibiotic treatment for suspected bacteraemia. Characteristics of patients were reviewed, and multi-variable logistic regression was performed to identify factors associated with CSS failure (i.e., persistence, recurrence or complications of bacteraemia).

RESULTS

We included 273 episodes of S. aureus LTCVC-associated CLABSI. CSS was chosen in 194 out of 273 (71%) cases and failed in 74 of them (38%). The main type of CSS failure was the persistence of bacteraemia (39 of 74 cases, 53%). Factors independently associated with CSS failure were: history of catheter infection (adjusted odds ratio (aOR) 3.18, 95% confidence interval (CI) 1.38-7.36), CLABSI occurring on an implantable venous access device (aOR 7.61, 95% CI 1.98-29.20) when compared with tunnelled-cuffed CVC, polymicrobial CLABSI (aOR 3.45, 95% CI 1.25-9.50), and severe sepsis at the initial stage of infection (aOR 4.46, 95% CI 1.18-16.82).

CONCLUSIONS

CSS was frequently chosen in children with S. aureus LTCVC-associated CLABSI, and failure occurred in one-third of cases. The identified risk factors may help clinicians identify children at risk for CSS failure.

Risk of infections related to endovascular catheters and cardiac implantable devices in hemodialysis patients

Patients requiring dialysis are extremely vulnerable to infectious diseases. The high burden of comorbidities and weakened immune system due to uremia and previous immunosuppressive therapy expose the patient on dialysis to more infectious events than the general population. The infectious risk is further increased by the presence of endovascular catheters and implantable cardiologic devices. The former is generally placed as urgent vascular access for dialysis and in subjects requiring hemodialysis treatments without autogenous arteriovenous fistula. The high frequency of cardiovascular events also increases the likelihood of implanting indwelling implantable cardiac devices (CIED) such as pacemakers (PMs) and defibrillators (ICDs). The simultaneous presence of CVC and CIED yields an increased risk of developing severe prosthetic device-associated bloodstream infections often progressing to septicemia. Although, antibiotic therapy is the mainstay of prosthetic device-related infections, antibiotic resistance of biofilm-residing bacteria reduces the choice of infection eradication. In these cases, the resolution of the infection process relies on the removal of the prosthetic device. Compared to CVC removal, the extraction of leads is a more complex procedure and poses an increased risk of vessel tearing. As a result, the prevention of prosthetic device-related infection is of utmost importance in hemodialysis (HD) patients and relies principally on avoiding CVC as vascular access for HD and placement of a new class of wireless implantable medical devices. When the combination of CVC and CIED is inevitable, prevention of infection, mainly due translocation of skin bacteria, should be a mandatory priority for healthcare workers.

Guidelines on vascular access for hemodialysis from the Brazilian Society of Angiology and Vascular Surgery

Chronic kidney disease is a worldwide public health problem, and end-stage renal disease requires dialysis. Most patients requiring renal replacement therapy have to undergo hemodialysis. Therefore, vascular access is extremely important for the dialysis population, directly affecting the quality of life and the morbidity and mortality of this patient population. Since making, managing and salvaging of vascular accesses falls within the purview of the vascular surgeon, developing guideline to help specialists better manage vascular accesses for hemodialysis if of great importance. Thus, the objective of this guideline is to present a set of recommendations to guide decisions involved in the referral, evaluation, choice, surveillance and management of complications of vascular accesses for hemodialysis.

Antimicrobial Treatment of Staphylococcus aureus Biofilms

Staphylococcus aureus is a microorganism frequently associated with implant-related infections, owing to its ability to produce biofilms. These infections are difficult to treat because antimicrobials must cross the biofilm to effectively inhibit bacterial growth. Although some antibiotics can penetrate the biofilm and reduce the bacterial load, it is important to understand that the results of routine sensitivity tests are not always valid for interpreting the activity of different drugs. In this review, a broad discussion on the genes involved in biofilm formation, quorum sensing, and antimicrobial activity in monotherapy and combination therapy is presented that should benefit researchers engaged in optimizing the treatment of infections associated with S. aureus biofilms.

[Diagnosis and treatment of catheter-related bloodstream infection in hemodialysis: 10 years later]

Patients in hemodialysis on central venous catheter as vascular access are at risk of infections. Catheter-related bloodstream infection is one of the most serious catheter-complications in hemodialysis patients. Its clinical and microbiological diagnosis is challenging. The implementation of empiric antibiotic therapy is based on old recommendations proposing the combination of a molecule targeting methicillin-resistant Staphylococcus aureus and a betalactamin active on P. aeruginosa, and also adapting this probabilistic treatment by carrying out a microbiological register on a local scale, which is rarely done. In our hemodialysis center at Bordeaux University Hospital, an analysis of the microorganisms causing all catheter-related bloodstream infection over the period 2018-2020 enabled us to propose, in agreement with the infectious disease specialists, an adapted probabilistic antibiotic therapy protocol. This approach allowed us to observe a low incidence of meticillinoresistance of Staphylococcus. For catheters inserted more than 6 months ago, we observed no Staphylococcus, no multi-resistant Pseudomonas, and only 2% of Enterobacteria resistant to cephalosporins. A frequent updating of the microbiological epidemiology of catheter-related bloodstream infection, in partnership with the infectious diseases team in each hemodialysis center, allowing an adaptation of the probabilistic antibiotic therapy, and seems to have a good feasibility. This strategy might favor the preservation of microbial ecology on an individual and collective scale in maintenance hemodialysis patients.

Microbial Repercussion on Hemodialysis Catheter-Related Bloodstream Infection Outcome: A 2-Year Retrospective Study

Background

Albeit growing technical advances in the design of hemodialysis catheters, intravascular catheter-related bloodstream infection (CRBSI) still represents an utmost clinical challenge to the health-care workers (HCWs). Data regarding the influence of the culprit organism on the scenario of CRBSI in the literature are extremely lacking. Thereby, this research was carried out.

Methods

We undertook a retrospective cohort study over an interval of 2 years, involving patients who underwent regular hemodialysis via catheters in the Renal Dialysis Unit (RDU) of Dr. Soliman Fakeeh Hospital (DSFH), Jeddah, Kingdom of Saudi Arabia (KSA). The study enrolled 139 patients (56.8% females and 43.2% males), with mean age of 60.79 ± 11.45 years.

Results

The aggregate rate of CRBSI was 5.1/1000 catheter days. Amongst the 139 study candidates confirmed of having CRBSI, while 69.8% of CRBSIs were ascribed to Gram-positive cocci, about one-third of the infectious episodes were secondary to Gram-negative bacilli. Interestingly, fever was the most common presentation of S. aureus CRBSI compared to CoNS and Gram-negative bacilli CRBSIs (20.9% versus 12.9% versus 6.5%, p= 0.0001), whereas CRBSIs due to CoNS were presented mainly with rigors (19.4%). Of note, CRBSIs caused by Gram-negative bacilli had a tendency to manifest with unusual symptoms such as vomiting or hypotension. Besides, they were more prone to involve hospitalization or ICU admission. In this study, no mortality was attributed to CRBSIs.

Conclusion

Our study disclosed that the illicit organism has a repercussion on the clinical presentation as well as the fate of CRBSI among hemodialysis patients. This highlights the worth of identifying the infected cases in a periodic manner, to avoid the occurrence of devastating complications. A large body of work from various hemodialysis centers should take place in the near future so as to provide more insight in this perspective.

Enhancement of Antibiofilm Activity of Ciprofloxacin against Staphylococcus aureus by Administration of Antimicrobial Peptides

Staphylococcus aureus can develop resistance by mutation, transfection or biofilm formation. Resistance was induced in S. aureus by growth in sub-inhibitory concentrations of ciprofloxacin for 30 days. The ability of the antimicrobials to disrupt biofilms was determined using crystal violet and live/dead staining. Effects on the cell membranes of biofilm cells were evaluated by measuring release of dyes and ATP, and nucleic acids. None of the strains developed resistance to AMPs while only S. aureus ATCC 25923 developed resistance (128 times) to ciprofloxacin after 30 passages. Only peptides reduced biofilms of ciprofloxacin-resistant cells. The antibiofilm effect of melimine with ciprofloxacin was more (27%) than with melimine alone at 1X MIC (p < 0.001). Similarly, at 1X MIC the combination of Mel4 and ciprofloxacin produced more (48%) biofilm disruption than Mel4 alone (p < 0.001). Combinations of either of the peptides with ciprofloxacin at 2X MIC released ≥ 66 nM ATP, more than either peptide alone (p ≤ 0.005). At 2X MIC, only melimine in combination with ciprofloxacin released DNA/RNA which was three times more than that released by melimine alone (p = 0.043). These results suggest the potential use of melimine and Mel4 with conventional antibiotics for the treatment of S. aureus biofilms.

Fibrin sheath disruption during guidewire exchange for bacteremia: Low recurrence of infection and preservation of vascular access sites

BACKGROUND

Catheter-associated bacteremia (CAB) often leads to removal of tunneled dialysis catheters with delayed insertion (RDI). Exchange over a guidewire (ExW) can be considered for access site preservation. Fibrin sheath disruption (FSD) during exchange is not standard practice for infected catheters. Here we present the first analysis of outcomes after such exchanges (ExW-FSD).

METHODS

Retrospective analysis of catheter exchanges and removals performed by interventional nephrology for bacteremia in 2008-2011 observed for 20.5 months. Charts were reviewed for recurrent or new bacteremia and death at 3 months, and for occurrence of thrombosis or stenosis along the catheter site. Catheter exchange with central venogram and fibrin sheath disruption was our standard of care in all patients presenting for CAB. RDI was performed either for tunnel infection, non-clearing of infection or at the request of referring physicians.

RESULTS

Over 4 years, 66 patients were treated for CAB. Forty-two patients underwent ExW-FSD, which was performed even for Staph. aureus, gram negative bacteremia or candidemia. RDI was performed in 24 cases. Bacteremia recurred in 3 (7%) patients after ExW-FSD, and in 7 (30%) cases after RDI (p = 0.02). There was no significant difference in new infections: 5 (12%) after ExW-FSD and 2 (8%) after RDI. There was no death within 3 months after ExW-FSD and 4 (27%) (p = 0.005) deaths in the RDI group.There was one new central venous stenosis in the ExW-FSD group (2%) with no loss of access site, and 8 (33%) patients developed thrombosis/stenosis along the prior catheter track after RDI (33%) (p = 0.006) with loss of access site in (21%).

CONCLUSIONS

In this retrospective analysis of treatment of CAB, ExW-FSD was associated with lower recurrence of bacteremia, lower death rate and a lower incidence of access site loss compared to RDI. These data support ExW-FSD use in patients with CAB.

Destruction of Staphylococcus aureus biofilms by combining an antibiotic with subtilisin A or calcium gluconate

In S. aureus biofilms, bacteria are embedded in a matrix of extracellular polymeric substances (EPS) and are highly tolerant to antimicrobial drugs. We thus sought to identify non-antibiotic substances with broad-spectrum activity able to destroy the EPS matrix and enhance the effect of antibiotics on embedded biofilm bacteria. Among eight substances tested, subtilisin A (0.01 U/mL) and calcium gluconate (CaG, Ca²⁺ 1.25 mmol/L) significantly reduced the biomass of biofilms formed by at least 21/24 S. aureus isolates. Confocal laser scanning microscopy confirmed that they both eliminated nearly all the proteins and PNAG from the matrix. By contrast, antibiotics alone had nearly no effect on biofilm biomass and the selected one (oxytetracycline-OTC) could only slightly reduce biofilm bacteria. The combination of OTC with CaG or subtilisin A led to an additive reduction (average of 2 log₁₀ CFU/mL) of embedded biofilm bacteria on the isolates susceptible to OTC (MBC < 10 μg/mL, 11/24). Moreover, these two combinations led to a reduction of the embedded biofilm bacteria higher than 3 log₁₀ CFU/mL for 20–25% of the isolates. Further studies are now required to better understand the factors that cause the biofilm produced by specific isolates (20–25%) to be susceptible to the combinations.

Long-Term Outcomes of the Flixene Vascular Graft Used for Haemodialysis

Introduction

The Flixene™ vascular graft (Maquet-Atrium Medical, Hudson, NH) has emerged as a new generation synthetic graft, which allows for early needling for haemodialysis. Most studies have shown satisfactory early results. The aim of this study is to report on long-term outcomes of the Flixene graft over eight years in a cohort of patients.

Methods

From February 2011 to September 2019, 61 patients had 64 arteriovenous graft fistulas (AVGs) by using the Flixene grafts. The median patient age was 67 years; the male to female ratio was 30:31. Diabetes was the reason for the majority of kidney failures (57%). The configuration of the grafts used was mostly upper arm straight AVG. The primary patency rate, secondary patency rate, and surgical complications were assessed.

Results

In a median follow-up of three years (interquartile range (IQR): 2 - 6), 36 of the AVGs required a fistulogram. Venous side stenosis was the most common cause of high venous pressure or AVG occlusion in 97%. The one-year primary patency rate was 30%. The secondary patency rate was 94.8%, 83.7%, and 77.7% at one, three, and five years, respectively. The longest functional AVG was observed for up to seven years.

Conclusions

This study has shown satisfactory long-term results of the Flixene graft used for hemodialysis. The Flixene graft could be needled within 72 hours without increased complications, which allows the creation of an AVG under an emergency setting to avoid the placement of a central venous catheter (CVC). This strategy should be advocated in future clinical practice.

Can vancomycin lock therapy extend the retention time of infected long-term catheters?

We assessed the success rate of vancomycin catheter lock therapy (VLT) in combination with systemic antimicrobials in patients with staphylococcal catheter-related bloodstream infection (C-RBSI). Over a 6-year period, we retrospectively collected clinical and microbiological data from patients with long-term central venous catheters and staphylococcal C-RBSI who were treated with systemic antimicrobials and VLT. We then assessed the success rate of VLT based on two criteria: 1) catheter retention time> 3 months and 2) catheter in place until end of use. We found 217 staphylococcal C-RBSI episodes, 115 (53.0%) of which were managed with conservative therapy. Of these, 76 (66.1%) were treated with VLT (85.5% coagulase-negative staphylococci and 14.5% Staphylococcus aureus). The success rate of VLT was 42.1% with criterion 1 and 71.1% with criterion 2. We did not find statistically significant differences between success and failure in the majority of the clinical data recorded. We only found differences for crude mortality in criterion 1 and for parenteral nutrition in criterion 2. The success of catheter retention using VLT was moderate, reaching slightly more than 70% when the catheter was kept in place until the end of use.

High success rate in salvage of catheter-related bloodstream infections due to Staphylococcus aureus, on behalf of project group of Italian society of nephrology

BACKGROUND

Catheter-related bloodstream infections caused by Staphylococcus aureus represent one of the most fearful infections in chronic haemodialysis patients with tunnelled central venous catheters. Current guidelines suggest prompt catheter removal in patients with positive blood cultures for S. aureus. This manoeuvre requires inserting a new catheter into the same vein or another one and is not without its risks.

METHODS

A protocol based on early, prompt diagnosis and treatment has been utilized in our renal unit since 2012 in an attempt to salvage infected tunnelled central venous catheters. We prospectively observed 247 tunnelled central venous catheters in 173 haemodialysis patients involving 167,511 catheter days.

RESULTS

We identified 113 catheter-related bloodstream infections (0.67 episodes per 1000 days/tunnelled central venous catheter). Forty were caused by S. aureus, including 19 by methicillin-resistant S. aureus (79% saved) and 21 by methicillin-sensitive S. aureus (90% saved), of which 34 (85%) were treated successfully. Eight recurrences occurred and six (75%) were successfully treated. A greater than 12 h time to blood culture positivity for S. aureus was a good prognostic index for successful therapy and tunnelled central venous catheter rescue.

CONCLUSION

Our data lead us to believe that it is possible to successfully treat catheter-related bloodstream infection caused by S. aureus and to avoid removing the tunnelled central venous catheter in many more cases than what has been reported in the literature. On the third day, it is mandatory to decide whether to replace the tunnelled central venous catheter or to carry on with antibiotic therapy. Apyrexia and amelioration of laboratory parameters suggest continuing systemic and antibiotic lock therapy for no less than 4 weeks, otherwise, tunnelled central venous catheter removal is recommended.

Complications of Hemodialysis Catheter Bloodstream Infections: Impact of Infecting Organism

BACKGROUND

Catheter-related bloodstream infections -(CRBSI) are associated with a high burden of morbidity and mortality, but the impact of infecting organism on clinical outcomes has been poorly studied.

METHODS

This retrospective analysis of a prospective vascular access database from a large academic dialysis center investigated whether the organism type affected the clinical presentation or complications of CRBSI.

RESULTS

Among 339 patients with suspected CRBSI, an alternate source of infection was identified in 50 (15%). Of 289 patients with CRBSI, 249 grew a single organism and 40 were polymicrobial. Fever and/or rigors were presenting signs in ≥90% of patients with Staphylococcus aureus or Gram-negative CRBSI, but only 61% of Staphylococcus epidermidis infections (p < 0.001). Hospitalization occurred in 67% of patients with S. aureus CRBSI versus 34% of those with S. epidermidis and 40% of those with a Gram-negative bacteria (p < 0.001). Admission to the intensive care unit was required in 14, 9, and 2% (p = 0.06); metastatic infection occurred in 10, 4, and 4% (p = 0.42); and median length of stay among patients admitted to the hospital was 4, 4, and 5.5 days (p = 0.60), respectively. Death due to CRBSI occurred in only 1% of patients with CRBSI.

CONCLUSION

CRBSI is confirmed in 85% of catheter-dependent hemodialysis patients in whom it is suspected. S. epidermidis CRBSI tends to present with atypical symptoms. S. aureus CRBSI is more likely to require hospitalization or intensive care admission. Metastatic infection is relatively uncommon, and death due to CRBSI is rare.

Diagnosis and treatment of catheter-related bloodstream infection: Clinical guidelines of the Spanish Society of Infectious Diseases and Clinical Microbiology and (SEIMC) and the Spanish Society of Spanish Society of Intensive and Critical Care Medicine and Coronary Units (SEMICYUC)

Catheter-related bloodstream infections (CRBSI) constitute an important cause of hospital-acquired infection associated with morbidity, mortality, and cost. The aim of these guidelines is to provide updated recommendations for the diagnosis and management of CRBSI in adults. Prevention of CRBSI is excluded. Experts in the field were designated by the two participating Societies (the Spanish Society of Infectious Diseases and Clinical Microbiology and [SEIMC] and the Spanish Society of Spanish Society of Intensive and Critical Care Medicine and Coronary Units [SEMICYUC]). Short-term peripheral venous catheters, non-tunneled and long-term central venous catheters, tunneled catheters and hemodialysis catheters are covered by these guidelines. The panel identified 39 key topics that were formulated in accordance with the PICO format. The strength of the recommendations and quality of the evidence were graded in accordance with ESCMID guidelines. Recommendations are made for the diagnosis of CRBSI with and without catheter removal and of tunnel infection. The document establishes the clinical situations in which a conservative diagnosis of CRBSI (diagnosis without catheter removal) is feasible. Recommendations are also made regarding empirical therapy, pathogen-specific treatment (coagulase-negative staphylococci, Staphylococcus aureus, Enterococcus spp., Gram-negative bacilli, and Candida spp.), antibiotic lock therapy, diagnosis and management of suppurative thrombophlebitis and local complications.

International experience with minocycline, EDTA and ethanol lock for salvaging of central line associated bloodstream infections

BACKGROUND

The use of long-term central venous catheters (CVCs) could lead to serious bloodstream infections. Removal of the infected CVC and reinsertion of a new CVC are not always feasible and alternative lock therapy may be considered. We conducted a multicenter trial to assess the efficacy and safety of the lock therapy.

METHODS

Between October 2013 and August 2014, we prospectively enrolled 20 patients with catheter-related bloodstream infections (CRBSIs) or central line-associated bloodstream infections (CLABSIs) in our sister institutions in three countries including Brazil, Lebanon, and Japan. The 20 patients who received M-EDTA-EtOH lock therapy were compared to 24 control patients who had their CVCs removed and a new CVC inserted.

RESULTS

Both groups had comparable clinical characteristics. In the lock therapy group, 95% of the patients had microbiological eradication within 96 h after starting lock therapy versus 83% of the patients in the control group (p = .36). In the lock group, the CVC was salvaged and retained for a median of 21 days (range 7-51) from the onset of bacteremia.

CONCLUSION

Our study suggests that M-EDTA-EtOH lock therapy may be an effective intervention to salvage long-term CVCs in the setting of CLABSI/CRBSI and hemodialysis cancer patients with limited vascular access.

Spanish Clinical Guidelines on Vascular Access for Haemodialysis

Vascular access for haemodialysis is key in renal patients both due to its associated morbidity and mortality and due to its impact on quality of life. The process, from the creation and maintenance of vascular access to the treatment of its complications, represents a challenge when it comes to decision-making, due to the complexity of the existing disease and the diversity of the specialities involved. With a view to finding a common approach, the Spanish Multidisciplinary Group on Vascular Access (GEMAV), which includes experts from the five scientific societies involved (nephrology [S.E.N.], vascular surgery [SEACV], vascular and interventional radiology [SERAM-SERVEI], infectious diseases [SEIMC] and nephrology nursing [SEDEN]), along with the methodological support of the Cochrane Center, has updated the Guidelines on Vascular Access for Haemodialysis, published in 2005. These guidelines maintain a similar structure, in that they review the evidence without compromising the educational aspects. However, on one hand, they provide an update to methodology development following the guidelines of the GRADE system in order to translate this systematic review of evidence into recommendations that facilitate decision-making in routine clinical practice, and, on the other hand, the guidelines establish quality indicators which make it possible to monitor the quality of healthcare.

Salvage of Hemodialysis Catheter in Staphylococcal Bacteremia: Case Series, Revisiting the Literature, and the Role of the Pharmacist

Catheter-related blood stream infections comprise a major concern in hemodialysis patients, leading to increased mortality, morbidity, and cost of treatment. Prompt appropriate systemic antibiotics treatment, which includes administration of appropriate systemic antibiotics and, frequently, catheter removal and replacement, is warranted. However, in hemodialysis patients, repeated catheter insertions may cause central vein stenosis and thrombosis which limits the future availability of hemodialysis access. Lock solutions containing antibiotics and anticoagulants, instilled directly into the catheter lumen after each dialysis, have been successfully utilized for catheter salvage but higher rates of recurrence and complications were observed in infections resulting from staphylococcal species. We report several cases of catheter salvage using antibiotic lock solution in staphylococcal bacteremia with the purpose of stimulating the interest in randomized clinical trials. Evaluating the risk and benefits of catheter salvage in this patient subset in light of optimized systemic antibiotic dosing, improved lock solution use, and multidisciplinary involvement, balanced with the critical need to prevent unnecessary vascular trauma, is of great importance.

Arteriovenous Grafts: Much Maligned But in Need of Reconsideration?

There are substantial variations in arteriovenous fistula (AVF) use among hemodialysis patients in different countries, in different regions of the U.S., and even in different hemodialysis units within a single metropolitan area. These variations persist after adjustment for patient demographics and comorbidities, suggesting that practice patterns play a major role in determining the frequency of AVF use. These observations led to vascular access guidelines urging nephrologists and surgeons to increase AVF creation in patients with chronic kidney disease. Over the past 20 years, as clinicians have adopted these guidelines, the prevalence of AVF use in hemodialysis patients has increased substantially. At the same time, clinicians have recognized important limitations of an unwavering "Fistula First" approach. First, a substantial proportion of AVFs fail to mature even when routine preoperative vascular mapping is used, leading to prolonged catheter dependence. Second, certain patient subgroups are at high risk for AVF nonmaturation. Third, nonmaturing AVFs frequently require interventions to promote their maturation. Fourth, AVFs that require such interventions have shortened cumulative patency. Fifth, arteriovenous grafts (AVG) have several advantages over AVFs, including lower primary failure rates, fewer interventions prior to successful cannulation, and shorter duration of catheter dependence with its associated risk of bacteremia. All these observations have led nephrologists to propose an individualized approach to vascular access, with AVG being preferred in patients who initiate hemodialysis with a catheter, particularly if they are at high risk for AVF nonmaturation and have a relatively short life expectancy.

Serratia marcescens bacteraemia outbreak in haemodialysis patients with tunnelled catheters due to colonisation of antiseptic solution. Experience at 4 hospitals

INTRODUCTION

The application of antiseptic solution for handling tunnelled catheters is recommended in patients undergoing haemodialysis. These routine antiseptic procedures in handling catheters are crucial to avoid complications. We report an outbreak of Serratia marcescens (S. marcescens) bacteraemia in numerous haemodialysis units of the Community of Madrid.

MATERIAL AND METHODS

The first cases of bacteraemia due to S. marcescens were isolated in December 2014. The Preventive Medicine Services were informed of the detection of an atypical pathogen in several patients, suspecting a probable nosocomial outbreak. Information from 4 centres with similar S. marcescens bacteraemia was analysed.

RESULTS

Twenty-one cases of bacteraemia related to S. marcescens were identified. The mean age of affected patients was 72±10 years. The mean time on haemodialysis of affected patients was 33±13 months (range: 3-83 months), the median time of tunnelled catheter was 22±13 months. In 11 cases the clinical picture was similar, with hypotension and general malaise during the haemodialysis session. Fever was present in a further 7 cases. In 3 cases the presentation was asymptomatic and was detected by blood cultures. All patients had tunnelled catheters (12 patients with catheter in the right jugular vein, 5 in the left jugular, 2 in the right femoral artery and 2 in the left subclavian artery). Gentamicin intravenous doses (1mg/kg) with catheter lock solution with ciprofloxacin post-dialysis were administered for 3 weeks in 6 patients. In 12 patients the treatment was ceftazidime (2g IV) plus catheter lock solution with the same antibiotic, for 2 weeks. Four patients received oral ciprofloxacin for 2 weeks, in one case together with IV vancomycin. The patients were asymptomatic and without new episodes 48hours after the treatment. No major complications were observed. The teams informed the health authorities of the situation, which then reported the presence of batches of antiseptic (chlorhexidine 0.05 and 2%) colonised by S. marcescens. Given the routine application of this antiseptic in handling catheters at these units, this was considered the source of contagion and new cases were not observed after the removal of the batches.

CONCLUSIONS

The presence of bacteraemia due to unconventional germs should alert us to a potential outbreak. The application of a solution contaminated by S. marcescens in haemodialysis catheters was the source of bacteraemia. The intravenous antibiotic treatment and the catheter lock solution allowed an excellent survival of patients and catheters.

Successful Salvage of Central Venous Catheters in Patients with Catheter-Related or Central Line-Associated Bloodstream Infections by Using a Catheter Lock Solution Consisting of Minocycline, EDTA, and 25% Ethanol

In cancer patients with long-term central venous catheters (CVC), removal and reinsertion of a new CVC at a different site might be difficult because of the unavailability of accessible vascular sites. In vitro and animal studies showed that a minocycline-EDTA-ethanol (M-EDTA-EtOH) lock solution may eradicate microbial organisms in biofilms, hence enabling the treatment of central line-associated bloodstream infections (CLABSI) while retaining the catheter in situ Between April 2013 and July 2014, we enrolled 30 patients with CLABSI in a prospective study and compared them to a historical group of 60 patients with CLABSI who had their CVC removed and a new CVC inserted. Each catheter lumen was locked with an M-EDTA-EtOH solution for 2 h administered once daily, for a total of 7 doses. Patients who received locks had clinical characteristics that were comparable to those of the control group. The times to fever resolution and microbiological eradication were similar in the two groups. Patients with the lock intervention received a shorter duration of systemic antibiotic therapy than that of the control patients (median, 11 days versus 16 days, respectively; P < 0.0001), and they were able to retain their CVCs for a median of 74 days after the onset of bacteremia. The M-EDTA-EtOH lock was associated with a significantly decreased rate of mechanical and infectious complications compared to that of the CVC removal/reinsertion group, who received a longer duration of systemic antimicrobial therapy. (This study has been registered at ClinicalTrials.gov under registration no. NCT01539343.).

Daptomycin antibiotic lock therapy for hemodialysis patients with Gram-positive bloodstream infections following use of tunneled, cuffed hemodialysis catheters: retrospective single center analysis

Catheter-related blood stream infection (CRBSI) is a major complication in hemodialysis patients. We assessed the efficacy of systemic daptomycin (DPT) plus DPT antibiotic lock therapy (DPT-ALT) for catheter salvage in patients with Gram-positive CRBSIs. This is a retrospective study of hemodialysis patients with tunneled and cuffed hemodialysis catheters. All patients were from a single institution in Taipei and received systemic DPT plus DPT-ALT for the treatment of Gram-positive CRBSI. Successful resolution of CRBSI was implemented. Resolution of fever within 48 hours, negative result of repeated blood cultures after resolution of fever, no clinical evidence of CRBSI relapse and no need for catheter removal were measured. Fifteen hemodialysis patients received DPT-ALT for CRBSI, nine with coagulase-negative Staphylococcus (CONS), two with methicillin-resistant Staphylococcus aureus (MRSA), three with methicillin-sensitive Staphylococcus aureus (MSSA) and one with polymicrobial infections. Systemic DPT plus DPT-ALT cured 11 patients (73.3%). Treatment failed in all three MRSA cases (two with MRSA and one with MRSA + Enterococcus faecalis). Retrospective design and small sample size were the limitations of this study. Systemic DPT plus DPT-ALT appears to be a promising treatment for CRBSI from CONS and MSSA, but not for MRSA CRBSI. Systemic DPT plus DPT-ALT should be considered for patients with CRBSIs caused by certain species.

Diagnosis and treatment of bacteremia and endocarditis due to Staphylococcus aureus. A clinical guideline from the Spanish Society of Clinical Microbiology and Infectious Diseases (SEIMC)

Both bacteremia and infective endocarditis caused by Staphylococcus aureus are common and severe diseases. The prognosis may darken not infrequently, especially in the presence of intracardiac devices or methicillin-resistance. Indeed, the optimization of the antimicrobial therapy is a key step in the outcome of these infections. The high rates of treatment failure and the increasing interest in the influence of vancomycin susceptibility in the outcome of infections caused by both methicillin-susceptible and -resistant isolates has led to the research of novel therapeutic schemes. Specifically, the interest raised in recent years on the new antimicrobials with activity against methicillin-resistant staphylococci has been also extended to infections caused by susceptible strains, which still carry the most important burden of infection. Recent clinical and experimental research has focused in the activity of new combinations of antimicrobials, their indication and role still being debatable. Also, the impact of an appropriate empirical antimicrobial treatment has acquired relevance in recent years. Finally, it is noteworthy the impact of the implementation of a systematic bundle of measures for improving the outcome. The aim of this clinical guideline is to provide an ensemble of recommendations in order to improve the treatment and prognosis of bacteremia and infective endocarditis caused by S. aureus, in accordance to the latest evidence published.

Clinical Usefulness of ¹⁸F-FDG PET/CT for the Detection of Infections of Unknown Origin in Patients Undergoing Maintenance Hemodialysis

Patients with end-stage renal disease undergoing maintenance hemodialysis (MHD) are highly prone to infections. The potential clinical usefulness of (18)F-FDG PET/CT for the detection of infections of unknown origin in this patient population remains unclear. This study was designed to investigate this issue.

METHODS

Between October 2011 and July 2014, a total of 104 adult MHD patients with sepsis underwent (18)F-FDG PET/CT for the detection of unknown infection foci. Follow-up was continued until October 2014. Positive (18)F-FDG PET/CT findings and mortality served as the main outcome measures.

RESULTS

Of the 104 study patients, 73 (70.2%) had positive (18)F-FDG PET/CT findings, and a total of 95 major infection foci were identified. Eighteen patients (24.6%) had at least 2 infection foci on (18)F-FDG PET/CT scans. Seven (53.8%) of the 13 patients with primary vascular access-related infections had concurrent metastatic foci. Twenty-eight patients (26.9%) had their treatments modified by (18)F-FDG PET/CT results. Multivariate logistic regression analysis demonstrated that low hemoglobin and high C-reactive protein levels at diagnosis were the independent predictors of positive (18)F-FDG PET/CT results. Twenty-seven patients (26.0%) died during their hospital stay, and 24 of them had positive (18)F-FDG PET/CT findings (P = 0.014). Positive (18)F-FDG PET/CT results were an independent predictor of mortality (hazard ratio, 3.896; 95% confidence interval, 1.039-14.613; P = 0.044).

CONCLUSION

Our results suggest that (18)F-FDG PET/CT may be clinically useful for detecting occult infection foci in end-stage renal disease patients undergoing MHD. In this population, positive (18)F-FDG PET/CT findings may lead to a significant change in clinical management and independently predict mortality.

Antibiotic lock therapy: review of technique and logistical challenges

Antibiotic lock therapy (ALT) for the prevention and treatment of catheter-related bloodstream infections is a simple strategy in theory, yet its real-world application may be delayed or avoided due to technical questions and/or logistical challenges. This review focuses on these latter aspects of ALT, including preparation information for a variety of antibiotic lock solutions (ie, aminoglycosides, beta-lactams, fluoroquinolones, folate antagonists, glycopeptides, glycylcyclines, lipopeptides, oxazolidinones, polymyxins, and tetracyclines) and common clinical issues surrounding ALT administration. Detailed data regarding concentrations, additives, stability/compatibility, and dwell times are summarized. Logistical challenges such as lock preparation procedures, use of additives (eg, heparin, citrate, or ethylenediaminetetraacetic acid), timing of initiation and therapy duration, optimal dwell time and catheter accessibility, and risks of ALT are also described. Development of local protocols is recommended in order to avoid these potential barriers and encourage utilization of ALT where appropriate.

Systematic review and meta-analysis on management of hemodialysis catheter-related bacteremia

Hemodialysis catheter-related bacteremia is a common clinical problem with several management options. We performed a systematic review and meta-analysis to determine cure proportions with systemic antibiotics, antibiotic lock solution, and guidewire exchange. We searched databases and registries; conference proceedings from relevant medical societies; and article reference lists. Data regarding management approach, cure, follow-up, recurrence, complications, and microbiology were abstracted and pooled from 28 selected publications. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated from a mixed effects logistic regression model. In total, 1596 patients with tunneled hemodialysis catheter-related bacteremia were divided into groups on the basis of treatment with systemic antibiotics (n=697), antibiotic lock solution (n=546), or guidewire exchange (n=353). Antibiotic lock solution and guidewire exchange had similar cure proportions that were superior to systemic antibiotics alone (OR, 2.08; 95% CI, 1.25 to 3.45; P<0.01 for antibiotic lock solution; OR, 2.88; 95% CI, 1.82 to 4.55; P<0.001 for guidewire exchange versus systemic antibiotics). Cure proportions were highest for coagulase-negative staphylococci followed by gram-negative rods and Staphylococcus aureus. Among S. aureus infections, guidewire exchange led to a higher cure proportion than systemic antibiotics or antibiotic lock solution (OR, 3.33; 95% CI, 1.17 to 9.46; P=0.02; OR, 4.72; 95% CI, 1.79 to 12.46; P=0.002, respectively). Thus, results of this study suggest that tunneled hemodialysis catheter-related bacteremia should be treated with either guidewire exchange or antibiotic lock solution. Future studies should address prospectively whether one strategy is better than the other overall and for specific pathogens.

Bacteriophage K antimicrobial-lock technique for treatment of Staphylococcus aureus central venous catheter-related infection: a leporine model efficacy analysis

PURPOSE

To determine whether a bacteriophage antimicrobial-lock technique can reduce bacterial colonization and biofilm formation on indwelling central venous catheters in a rabbit model.

MATERIALS AND METHODS

Cuffed central venous catheters were inserted into the jugular vein of female New Zealand White rabbits under image guidance. Catheters were inoculated for 24 hours with broth culture of methicillin-sensitive Staphylococcus aureus. The inoculum was aspirated, and rabbits were randomly assigned to two equal groups for 24 hours: (i) untreated controls (heparinized saline lock), (ii) bacteriophage antimicrobial-lock (staphylococcal bacteriophage K, propagated titer > 10(8)/mL). Blood cultures were obtained via peripheral veins, and the catheters were removed for quantitative culture and scanning electron microscopy.

RESULTS

Mean colony-forming units (CFU) per cm(2) of the distal catheter segment, as a measure of biofilm, were significantly decreased in experimental animals compared with controls (control, 1.2 × 10(5) CFU/cm(2); experimental, 7.6 × 10(3); P = .016). Scanning electron microscopy demonstrated that biofilms were present on the surface of five of five control catheters but only one of five treated catheters (P = .048). Blood culture results were not significantly different between the groups.

CONCLUSIONS

In a rabbit model, treatment of infected central venous catheters with a bacteriophage antimicrobial-lock technique significantly reduced bacterial colonization and biofilm presence. Our data represent a preliminary step toward use of bacteriophage therapy for prevention and treatment of central venous catheter-associated infection.

Long-term catheterization: current approaches in the diagnosis and treatment of port-related infections

Since the first description in 1982, totally implanted venous access ports have progressively improved patients' quality of life and medical assistance when a medical condition requires the use of long-term venous access. Currently, they are part of the standard medical care for oncohematologic patients. However, apart from mechanical and thrombotic complications, there are also complications associated with biofilm development inside the catheters. These biofilms increase the cost of medical assistance and extend hospitalization. The most frequently involved micro-organisms in these infections are gram-positive cocci. Many efforts have been made to understand biofilm formation within the lumen catheters, and to resolve catheter-related infection once it has been established. Apart from systemic antibiotic treatment, the use of local catheter treatment (ie, antibiotic lock technique) is widely employed. Many different antimicrobial options have been tested, with different outcomes, in clinical and in in vitro assays. The stability of antibiotic concentration in the lock solution once instilled inside the catheter lumen remains unresolved. To prevent infection, it is mandatory to perform hand hygiene before catheter insertion and manipulation, and to disinfect catheter hubs, connectors, and injection ports before accessing the catheter. At present, there are still unresolved questions regarding the best antimicrobial agent for catheter-related bloodstream infection treatment and the duration of concentration stability of the antibiotic solution within the lumen of the port.

Antibiotic-lock therapy: a clinical viewpoint

Antibiotic lock therapy (ALT) - instillation of high concentrations of anti-microbial agent with or without anti-coagulant into the lumen of central venous catheters - is considered a valid conservative treatment for catheter-related bloodstream infection (CRBSI) in patients highly dependent on maintaining the catheter. Results from randomized controlled studies have indicated that the effectiveness of ALT is moderate, but recent findings from experimental studies and observational case series point to considerable efficacy and safety of this therapy, which is usually associated with concomitant systemic treatment. In this article, the current knowledge about ALT for patients with CRBSI is reviewed and discussed, with emphasis on existing controversies and the results obtained according to the various uses of the catheters and the etiologies of infection.

Predictors of Failure of Catheter Salvage in Incident Hemodialysis Patients

Purpose

Catheter-related bloodstream infection is a frequent complication for patients who use catheter as dialysis access. This study was performed to identify the risk factors for failed catheter salvage.

Methods

We enrolled patients who received non-tunneled catheters as initial vascular access during a two-year period. Catheter salvage was attempted in all symptomatically mild patients. Patients were prospectively followed for 8 weeks starting from the day of infection. Risk factors for salvage failure were explored.

Results

A total of 77 bacteremia episodes occurred in 69 patient, with an infection rate of 1.61 per 1,000 catheter days. Salvage was successful in 73.4% of all episodes. We found that higher ferritin levels (greater vs. lower than 500 mg/l, (odds ratio (OR) 6.388, 95% confidence interval (CI) 2.073, 19.686), higher phosphate levels (greater vs. lower than 5.5 mg/dl, OR 4.084, 95% CI 1.391, 11.978) and shorter time intervals between catheterization and infection (within vs. beyond 3 weeks, OR 4.190, 95% CI 1.279, 13.725) predicted salvage failure.

Conclusions

Catheter salvage can be a reasonable initial strategy for symptomatically mild patients. We propose salvaging aggressively and waiting watchfully; however, clinical judgment is prior to any specific management protocol.

Surface-Treated versus Untreated Large-Bore Catheters as Vascular Access in Hemodialysis and Apheresis Treatments

Background. Catheter-related infections, thrombosis, and stenosis are among the most frequent complications associated with catheters, which are inserted in vessels. Surface treatment processes of the outer surface, such as ion-beam-assisted deposition, can be used to mitigate such complications. Methods. This retrospective study (1992-2007) evaluated silver-coated (54 patients) and noncoated (105 patients) implanted large-bore catheters used for extracorporeal detoxification. The catheters were inserted into the internal jugular or subclavian veins. After removal, the catheters were cultured for bacterial colonization using standard microbiologic assays. They also were examined using scanning electron microscope. Results. The silver coated catheters showed a tendency towards longer in situ time. The microbiologic examinations of the catheter tips were in both catheter types high positive, but not significant. Conclusion. The silver-coated catheters showed no significantly reduction in infection rate by evaluation of all collected data in this retrospective study. There was no association between both catheters in significantly reducing savings in treatment costs and in reducing patient discomfort. Other new developed catheter materials such as the microdomain-structured inner and outer surface are considered more biocompatible because they mimic the structure of natural biological surface.

Prevention and management of central line-associated bloodstream infections in hospital practice

In this article aimed at hospitalists, we examine the literature on preventive measures for central line-associated bloodstream infections (CLABSIs) and optimal management once a CLABSI has been established. We focus on a number of core preventive measures and the contemporary approach of bundling these measures for maximal impact in reducing infection rates. We then discuss empiric and pathogen-specific antibiotic therapy, including the role of newer antimicrobial agents, as well as the management of an infected central venous catheter.

Clinical management of dialysis catheter-related bacteremia with concurrent exit-site infection

Dialysis catheter-related bacteremia (CRB) can frequently be treated with systemic antibiotics, in conjunction with an antibiotic lock, in an attempt to salvage the catheter. It is unknown whether CRB associated with an exit-site infection can be treated with such an approach. We retrospectively queried a prospective, computerized vascular access database, and identified 1436 episodes of CRB, of which 64 cases had a concurrent exit site. The frequency of concurrent exit-site infection was 9.6% with Staphylococcus epidermidis, 6.1% with Staphylococcus aureus, and only 0.7% with Gram negative CRB (p < 0.001 for Staphylococcus vs. Gram negative rods). Five serious complications (four major sepses and one endocarditis) occurred in 24 patients with S. aureus infection, but none in 32 episodes of S. epidermidis infection (p = 0.01). Catheter survival was significantly shorter in patients with S. aureus infections. The median catheter survival (without infection or dysfunction) was 14 days with S. aureus vs. 30 days with S. epidermidis infection (p = 0.035). In conclusion, concurrent exit-site infection is seen most commonly in association with Staphylococcal CRB. When the infecting organism is S. epidermidis, attempted salvage with systemic antibiotics and an antibiotic lock is reasonable. However, prompt catheter removal is indicated when the pathogen is S. aureus.

The spectrum of infections in catheter-dependent hemodialysis patients

BACKGROUND AND OBJECTIVES

Catheter-dependent hemodialysis patients may develop access-related and nonaccess-related infections that may be managed in the outpatient arena or in the hospital. The goal of this study was to quantify infections in such patients, to characterize their clinical presentations, and to evaluate factors determining need for hospitalization.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We collected prospective data on the clinical management of catheter-dependent hemodialysis patients with suspected infection at a large dialysis center. We documented the presenting symptoms, type of infection, pathogen, and whether hospitalization occurred.

RESULTS

An infection was suspected in 305 separate cases and confirmed in 88%. The 268 diagnosed infections included catheter-related bacteremia (69%), another access-related infection (19%), and nonaccess-related infection (12%). The overall frequency of infection was 4.62 per 1000 catheter-days. Hospitalization occurred in 37% of all infections, but it varied greatly (72% for nonaccess-related infection, 34% for catheter-related bacteremia, and 4% for exit-site infection). Among patients with catheter-related bacteremia, the likelihood of hospitalization varied by pathogen, being 53% for Staphylococcus aureus, 30% for Enterococcus, 23% for Staphylococcus epidermidis, and 17% for gram-negative rods (P < 0.001). The likelihood of hospitalization was not associated with age, gender, or diabetes. Fever was a presenting symptom in only 47% of cases of catheter-related bacteremia.

CONCLUSIONS

Catheter-dependent patients have a high burden of infection. It is important to evaluate patients with suspected infection for various access-related and nonaccess-related infections. A low threshold is indicated for suspecting catheter-related bacteremia because the patients frequently present without fever.

Anti-infective locks for treatment of central line-associated bloodstream infection: a systematic review and meta-analysis

Central line-associated bloodstream infections (CLABSI) are associated with considerable morbidity, mortality and economic costs. In most cases, catheter removal is considered an essential component of managing CLABSI. However, in patients with poor access, catheter salvage may have to be attempted rather than removal and replacement of catheters. Anti-infective lock therapy (ALT) - instilling an antibiotic or antiseptic into the catheter lumen - is a novel way of treating CLABSI while attempting to salvage the catheter. However, data on the efficacy of ALT for catheter salvage is limited. In this systematic review, we critically review the evidence regarding the use of ALT for catheter salvage. We identified 8 studies including a total of 396 patients that compared ALT with systemic antibiotic therapy alone or an alternate method of catheter salvage (guidewire replacement). We found that the combination of systemic antibiotics and culture-guided lock therapy was superior to systemic antibiotics alone (OR: 0.20, 95% CI: 0.10-0.39), with 10% of locked patients requiring replacement compared to 33% of subjects without locks. There was a 20% relapse rate in the ALT group and a 30% relapse rate in the control group (OR: 0.43, 95% CI: 0.18-1.03). There was insufficient data on catheter exchange over a wire compared with ALT to permit conclusions. Our data support the use of ALT in conjunction with systemic antibiotics for catheter salvage. Large randomized controlled trials of ALT examining dose, dwell times and relapse rates stratified by infecting pathogen are needed.

Clinical outcomes of antimicrobial lock solutions used in a treatment modality: a retrospective case series analysis

BACKGROUND

Antimicrobial lock therapy (ALT) may be considered as adjunctive therapy in the treatment of catheter-related bloodstream infections (CRBSI) when catheter removal is not a favorable option.

OBJECTIVE

To evaluate the outcomes associated with ALT as adjunctive treatment of CRBSI.

METHODS

This was a 24-month retrospective case series analysis evaluating patients treated for more than 24 hours with ALT. The primary outcome was blood culture sterilization for 30 days posttherapy. The impact of ALT duration and time to initiation on central venous catheter (CVC) salvage were evaluated. Logistic regression modeled the association between ALT and sterilization rates, with a prespecified level of significance (α) of 0.1.

RESULTS

Twenty-six cases were included in data analysis. Patients included ranged from 5 months to 82 years of age; 77% of patients were receiving total parenteral nutrition or chemotherapy. The majority of patients received vancomycin, daptomycin, or gentamicin combined with heparin in a lock solution. Blood culture sterilization was achieved in 69.2% of cases, and sterilization plus CVC retention was achieved in 11 cases (42.3%). Longer durations of ALT (≥9 days) were significantly correlated with blood culture sterilization (odds ratio = 1.367, P = 0.077).

CONCLUSION

ALT used as an adjunct to systemic therapy for adequate duration in CRBSI can achieve CVC sterilization and retainment without subsequent infectious complications.