Comparative Effectiveness of 30% Trisodium Citrate and Heparin Lock Solutions in Preventing Infection and Dysfunction of Hemodialysis Catheters: a Randomized Controlled Trial (CITRIM Trial)

METHODS Study Design This double blind randomized controlled trial (RCT) was conducted from July 2012 until July 2014 in the dialysis and transplantation unit of a Brazilian university hospital. The patients were randomly assigned to have their catheter locked with either unfractionated sodium heparin 5000 U/mL or 30% trisodium citrate. The randomization was performed through a computer-generated list of random numbers in blocks of six. Patients and investigators were unaware of the treatment assignments. Allocation concealment was performed using opaque, sealed envelopes for assignment.

After each hemodialysis (HD) session, patients assigned to 30%TSC had their catheter lumens flushed with 0.9% sodium chloride and locked with a volume of 30% TSC solution equivalent to the catheter internal lumen. Patients assigned to heparin had their catheter lumens flushed with 0.9% sodium chloride and locked with a volume of 5000 U/mL heparin equivalent to CVC internal lumen. Catheter care was according to international guidelines, including strict asepsis on insertion and exit-site dressing changes after each HD session by staff wearing masks and sterile gloves.

SELECTION OF PATIENTS Patients were eligible for enrollment in the RCT when they were older than 18 years and had chronic or acute renal failure that required hemodialysis through a catheter. Patients admitted to the intensive care ward, receiving a tunneled catheter, with suspected heparin-induced thrombocytopenia, allergy to heparin or TSC30%, with systemic or localized infection or pregnant women were excluded. The site of insertion and specific type of catheter were decided by the interventionist physician.

MAIN OUTCOMES Catheter related bloodstream infection (CRBSI): CRBSI was defined as fever and/or chills during a dialysis session and at least one positive blood culture, with no other obvious cause of infection after careful clinical examination. The management of the CRBSI was performed according to guidelines. Empirical antibiotic therapy was immediately given. The catheter was removed if there was isolation of S. aureus or fungus, or there was no clinical recovery within 48 hours of antibiotic treatment.

Catheter dysfunction: Dysfunction was defined as a persistent inability to obtain a blood flow above 200 mL/min. In this situation, the catheter was removed or exchanged over guidewire.