ETHANOL LOCK VERSUS ANTIBIOTIC LOCK - A PROSPECTIVE RCT TO SALVAGE CATHETERS IN CRBSI IN PATIENTS UNDERGOING MAINTAINENCE HEMODIALYSIS VIA TUNNELED CUFFED CATHETER

Introduction:

Catheter-Related Blood Stream Infection (CRBSI) is one of the major causes of morbidity and mortality in patients undergoing hemodialysis (HD) through Tunneled cuffed catheter (TCC). Majority of CRBSIs are associated with the formation of a microbial biofilm on the device. As systemic antibiotics have limited ability in countering the biofilm, an antibiotic or antiseptic lock has the ability to target the biofilm directly. Different locking solutions have been tried in the past with varying success. Antibiotic locking therapy (ALT), a highly concentrated antibiotic solution mixed with heparin,  has been studied extensively and has proven to be beneficial for catheter salvage. Ethanol locking therapy (ELT) , a 70 % concentration ethanol solution, has the advantages of needing a shorter duration of therapy & less chance of antimicrobial resistance with good success rates. Aim was to compare the efficacy of ELT versus ALT in salvage of TCC at 30 days post treatment in CRBSI patients. Secondary objective was to study the safety of both these treatment protocols.

Methods:

This was a prospective single blinded randomized controlled trial, carried out from Sept 2022 to May 2024 in a tertiary referral Nephrology center in India. All patients who presented with fever &/or chills during/after hemodialysis through TCC in the absence of any other source of infection were considered as possible CRBSI. Their blood cultures were drawn and injectable broad spectrum antibiotics started (Vancomycin & Ceftazidime). Patients were then randomized into one of the two groups to receive ELT or ALT. Ethanol lock therapy: 2 ml 70% ethanol - instilled into each lumen of the TCC & left in situ for 1 hour daily for 5 days. Antibiotic lock therapy  - 2 ml Antibiotic lock solution (1.0 ml Vancomycin {5 mg} + 0.5 ml Ceftazidime {5mg}+ 0.5 ml Heparin {5000 U} ) instilled into each lumen & left in situ till next HD session. ALT was given for total of 5 sessions of HD. Patients were re-evaluated at 30 days post treatment to look for salvage of TCC, later followed up for 150 days to watch for adverse events and other parameters.

Results:

The study design and enrollment of patients were done as mentioned in Fig.1. The baseline characteristics were similar in the groups. ELT was successful in reaching primary end point of TCC salvage for 30 days in 23 out of 30 patients (76.7%); compared to 24 out 30 (80 %) with ALT, although the difference was not statistically significant (p-value-0.347). Treatment success, defined as disappearance of fever and ability to carry out HD via the TCC was 86.7 % in ELT group and 90% in ALT group(p- value - 0.86). Mean TCC survival was longer with ALT (93.76 +/- 116 days) compared to ELT (71.7 +/- 75 days) (P-value- 0.146). The number of patients who reached a favorable outcome for TCC removal (Transplant/ AVF working /switch to CAPD) was similar in both groups ( 66.7 % in ELT v/s 66.7 % in ALT). In blood cultures, Gram negative bacteria were more common, of which Enterobacter sp. and Pseudomonas were the commonest. One death in each group was related to CRBSI. Two adverse events observed, one patient developed infective endocarditis & two developed poor flow in catheter.

Conclusions:

Ethanol locking treatment & antibiotic locking treatment as a part of catheter salvage therapy are almost equally effective with good success rates. No statistically significant difference was found between the two treatment arms. Gram negative organisms are the commoner cause of CRBSI, and can be effectively tackled by these locking solutions. Generally, both are safe treatment options with minimal side effects, still we should be vigilant for deep seated infections at follow up. Even with the usage of locking solutions and systemic antibiotics, we may not be able to salvage 1 in 5 catheters.

The content presented in this abstract was previously submitted for ISN(Indian Society of Nephrology)-WZ mid-term meeting, July 2024.

I have no potential conflict of interest to disclose.

I did not use generative AI and AI-assisted technologies in the writing process.