Antibiotic-lock therapy for long-term catheter-related bacteremia: a review of the current evidence

A Local Experience of Antibiotic Lock Therapy as an Adjunctive Treatment for Central Venous Catheter-Related Bloodstream Infections in Pediatric Oncology and Hematology Patients

BACKGROUND

One of the main drawbacks of tunneled central venous catheters (CVCs) is catheter-related bloodstream infections (CRBSIs). Antibiotic lock therapy (ALT) can be combined with systemic antibiotics to achieve catheter salvage. Our objectives are to describe cases of CRBSI and our experience with ALT in a pediatric oncology-hematology ward.

METHODS

a retrospective descriptive study of pediatric CRBSI cases in a Spanish oncology-hematology unit from 2007 to 2017 was conducted. We collected demographic, clinical, and microbiological data from all patients.

RESULTS

fifty-eight CRBSIs were diagnosed in thirty-nine patients; 72.9% of these patients were male, with a median age of 42.1 months. The main underlying diseases were leukemia/lymphoma (51.7%) and solid tumors (32.7%). Thirty-five (60.3%) CRBSIs were caused by Gram-positive cocci, of which 70.6% were coagulase-negative Staphylococci, and sixteen (27.6%) were caused by Gram-negative bacilli. We treated 41/58 (71%) cases with ALT. A total of 12/17 (71%) CVCs that were not treated with adjunctive ALT were removed, compared with 13/41 (32%) that were treated with ALT (relative risk (RR), 0.449; confidence interval (CI), 95%: 0.259-0.778, p = 0.004). Major reasons to remove the CVC in the CRBSI-ALT group were local insertion/pocket site infection (23%), persistent symptoms (23%), and infectious' relapses (15%).

CONCLUSIONS

ALT was shown to be an effective approach to keeping the CVC in place, with no added adverse effects.

Catheter-related bloodstream infection in end-stage kidney disease: a Canadian narrative review

Purpose of the review

Patients with end-stage renal disease (ESRD) are at a high risk of bacterial infection. We reviewed publications on risk factors, prevention, and treatment paradigms, as well as outcomes associated with bacterial infection in end-stage kidney disease. We focused in particular on studies conducted in Canada where rates of haemodialysis catheter use are high.

Sources of information

We included original research articles in English text identified from MEDLINE using search terms ‘chronic kidney failure’, ‘renal dialysis’, or ‘chronic renal insufficiency’, and ‘bacterial infection’. We focused on articles with Canadian study populations and included comparisons to international standards and outcomes where possible.

Findings

Bacterial infections in this setting are most commonly due to Gram-positive skin flora, particularly Staphylococcus, with methicillin-resistant Staphylococcus aureus (MRSA) carrying a poorer prognosis. Interventions that may decrease mortality from sepsis include a collaborative care model that includes a nephrology team, an infectious disease specialist, and use of standardized care bundles that adhere to proven quality-of-care indicators. Decreased infectious mortality may be achieved by ensuring appropriate antibiotic selection and dosing as well as avoiding catheter salvage attempts. Reduction in bloodstream infection (BSI) incidence has been observed with the use of tPA catheter-locking solutions and the use of mupirocin or polysporin as a topical agent at the catheter exit site, as well as implementing standarized hygiene protocols during catheter use.

Limitations

There has been a paucity of randomized controlled trials of prevention and treatment strategies for catheter-related BSIs in haemodialysis. Some past trials have been limited by lack of blinding and short duration of follow-up. Microbiological epidemiology, although well characterized, may vary by region and treatment centre.

Implications

With the high prevalence of catheter use in Canadian haemodialysis units, further studies on long-term treatment and preventative strategies for BSI are warranted.

Antifungal lock therapy

The widespread use of intravascular devices, such as central venous and hemodialysis catheters, in the past 2 decades has paralleled the increasing incidence of catheter-related bloodstream infections (CR-BSIs). Candida albicans is the fourth leading cause of hospital-associated BSIs. The propensity of C. albicans to form biofilms on these catheters has made these infections difficult to treat due to multiple factors, including increased resistance to antifungal agents. Thus, curing CR-BSIs caused by Candida species usually requires catheter removal in addition to systemic antifungal therapy. Alternatively, antimicrobial lock therapy has received significant interest and shown promise as a strategy to treat CR-BSIs due to Candida species. The existing in vitro, animal, and patient data for treatment of Candida-related CR-BSIs are reviewed. The most promising antifungal lock therapy (AfLT) strategies include use of amphotericin, ethanol, or echinocandins. Clinical trials are needed to further define the safety and efficacy of AfLT.

Antifungal lock therapy

The widespread use of intravascular devices, such as central venous and hemodialysis catheters, in the past 2 decades has paralleled the increasing incidence of catheter-related bloodstream infections (CR-BSIs). Candida albicans is the fourth leading cause of hospital-associated BSIs. The propensity of C. albicans to form biofilms on these catheters has made these infections difficult to treat due to multiple factors, including increased resistance to antifungal agents. Thus, curing CR-BSIs caused by Candida species usually requires catheter removal in addition to systemic antifungal therapy. Alternatively, antimicrobial lock therapy has received significant interest and shown promise as a strategy to treat CR-BSIs due to Candida species. The existing in vitro, animal, and patient data for treatment of Candida-related CR-BSIs are reviewed. The most promising antifungal lock therapy (AfLT) strategies include use of amphotericin, ethanol, or echinocandins. Clinical trials are needed to further define the safety and efficacy of AfLT.

Knowledge and practices regarding prevention of infections associated with central venous catheters: a survey of intensive care unit medical and nursing staff

BACKGROUND

Infections associated with central venous catheters (CVCs) are associated with considerable morbidity and mortality.

METHODS

We conducted a survey to evaluate the theoretical knowledge and practices of intensive care unit doctors and nursing staff regarding CVC-related infections.

RESULTS

A questionnaire was distributed to 345 doctors and nurses. The response rate was 71.6%. Of the responders, 84.9% worked in public hospitals, 40% had been trained in CVC-related infection issues, and 27% were familiar with the relevant Centers of Disease Control and Prevention guidelines. The mean percentage of correct answers (± standard deviation) on the 3 parts of the questionnaire were 42.9% ± 16.2%, 86.9% ± 9.5%, and 85.4% ± 7.2%. In the subset of questions referring to procedures that were doctors' exclusive responsibility, 13.6% of the doctors answered all questions correctly. Age >37 years, awareness of relevant official guidelines, working in a private hospital, and being a doctor were identified as independent variables associated with high scores in knowledge regarding the prevention of CVC-related infections. Female sex and training in infection prevention were associated with higher scores on the part evaluating adherence to specific practices regarding CVC insertion, whereas being a nurse was associated with higher scores on the part evaluating CVC maintenance.

CONCLUSION

Our findings suggest that there is a need for increased theoretical knowledge and improvement in practices regarding CVC care. Educational programs directed at doctors and nurses working in intensive care units may aid this effort.

New antibiotic agents for bloodstream infections

Infections due to multidrug-resistant pathogens have shown a dramatic worldwide increase in prevalence. Bloodstream infections (BSIs) represent an important cause of morbidity and mortality in hospitalised patients. Research in the field led to the introduction of several novel antibiotic agents in the fight against bacterial pathogens. New antibiotics used against Gram-positive bacteria, mainly meticillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci, include daptomycin, linezolid, quinupristin/dalfopristin and semisynthetic lipoglycopeptides. Among the Gram-negative bacteria, extended-spectrum beta-lactamase-producing Enterobacteriaceae as well as highly resistant Pseudomonas and Acinetobacter isolates are of particular concern. Doripenem is a recently approved carbapenem. Polymyxins are reconsidered as valuable therapeutic options for Gram-negative infections. Tigecycline, a glycylcycline, and ceftobiprole, a novel cephalosporin under investigation, have activity both against Gram-positive and Gram-negative organisms. In addition to the above agents, alternative treatment approaches that require further investigation have also been introduced into clinical practice. These include antibiotic lock therapy and continuous intravenous administration of antibiotics. In this article, we review the above treatment options for BSIs based on current clinical evidence. Comparative trials specifically focusing on patients with bacteraemia were generally not performed; however, a proportion of patients from the reported studies did have bacteraemia.

Empiric therapy for intravenous central line infections and nosocomially-acquired acute bacterial endocarditis

Intravascular catheters are essential devices in the intensive care unit, yet catheter-related bloodstream infections (CR-BSI) are associated with increased morbidity and mortality, prolonged hospitalization, and increased medical costs. Management of a CR-BSI requires antibiotics, with or without catheter removal, depending on patient and etiologic factors. Because of the high frequency of staphylococcal infections, it is wise to use a glycopeptide empirically. Extra coverage for Gram-negative bacilli should be administered in severely ill or immunocompromised patients. Once culture and sensitivity results are known, antibiotic therapy can be more selective.