Comment to Question 1

Whenever possible, non-cuffed catheters should be removed when catheter-associated bacteraemia is recognized. Infected catheters that show signs of accompanying exit-site or tunnel infection (erythema or pus at exit-site) should be cultured and subsequently removed. Empiric antibiotic should target both gram-positive and gram-negative organisms. The empiric treatment involves the administration of Cefazolin (1 gr iv posHD) in low risk patients and Tobramycin (100 mg postHD). Vancomycin (20 mg/kg weekly dose, 500 mg should be added after each HD session if a high-flux dialyser is used) should be used in high-risk patients or in centres with moderate-high risk for methycillin resistant staphylococcus aureus infection. Specific antimicrobial therapy should replace empiric therapy as soon as identity of the bacterial isolate is determined. Therapy should be continued for 10-14 days in non-compromised cases (this topic is subject to controversy). Antibiotic therapy without catheter removal is unlikely to eradicate catheter-related bacteraemia.
In the case of cuffed tunnelized catheters, salvage can be tried in stable patients, especially when an alternate site for vascular access is difficult or unavailable. The same i.v. antibiotic protocol used for non-cuffed catheters can be applied. Together with parenteral ATB, urokinase (first day) followed by antibiotic heparin catheter lock (vancomycin or cephalosporin or gentamycin) after the dialysis session has proved useful. Two to three weeks of therapy has been advocated to rescue tunnelled catheters. Other authors have recommended catheter exchange over a guidewire together with prolonged parenteral antibiotic treatment (at least 3 weeks).
The catheter should be removed if the patient becomes hemodynamically unstable, if the fever persists, if cultures remain positive after two days or in cases of frequent recurrent infection.
Catheter replacement should be delayed at least 24 to 48 hours.
Cultures should be taken from both the catheter and a peripheral site.
Patients who remain febrile or have positive cultures after catheter removal should undergo a thorough examination for infectious metastatic complications (such as endocarditis, vertebral abscess, and osteomyelitis).