Impact of gentamicin locking on central venous catheter-associated infection in hemodialysis patients

FREIAT-Ecuador experience (2017–2026).

Abstract

Introduction: Central venous catheter (CVC)-associated infection is a major complication in patients undergoing hemodialysis, increasing morbidity and mortality, healthcare costs, and hospitalizations. Various preventive strategies have been implemented to reduce its incidence, including intraluminal antibiotic locking. The aim of this study was to identify factors associated with CVC-related infection and to evaluate the efficacy of the gentamicin locking protocol implemented at FREIAT starting in 2022.

Methods: A retrospective observational study was conducted at a hemodialysis unit in Ecuador (FREIAT). Records of 197 patients with CVCs from 2017 to 2026 were analyzed. Variables evaluated included demographics, comorbidities, nutritional status, personal hygiene, catheter dwell time, and the use of gentamicin locking starting in 2022. Descriptive and comparative analyses were performed, using tests of association, to determine factors linked to the presence of infection.

Results: A total of 197 infection episodes were analyzed. The mean age was 58.6 ± 17.7 years, and 57.1% of the patients were female. Arterial hypertension was present in 87.3% of cases, and diabetes mellitus in 48.2%. The mean catheter dwell time was 14.7 ± 13.6 months. Of the 197 episodes evaluated, 78 (39.6%) yielded positive cultures and 119 (60.4%) yielded negative cultures. The isolated microorganisms were predominantly Gram-negative bacilli, notably Escherichia coli, Enterobacter spp., and Klebsiella pneumoniae. Among Gram-positive cocci, the most frequent microorganisms were coagulase-negative Staphylococcus and Staphylococcus aureus. When comparing episodes based on the use of gentamicin lock therapy, the proportion of positive cultures was 41.5% in patients without the lock and 36.7% in those who received the gentamicin lock, representing a relative reduction of 11.6%. However, this difference did not reach statistical significance (p=0.597). It should be noted that, following gentamicin use, there were 7 cases of coagulase-negative *Staphylococcus* isolation that could be considered external contamination; additionally, 6 episodes did not involve gentamicin lock therapy for various reasons, and a culture sample taken from one newly admitted patient tested positive. Following the implementation of the protocol, a progressive decrease in the annual number of infections was observed, dropping from 16 episodes in 2022 to 8 in 2023, 4 in 2024, 4 in 2025, and zero during the analyzed period of 2026. Furthermore, a trend toward lower serum albumin levels was observed in infected patients. Poor personal hygiene was significantly associated with a higher percentage of infections. The majority of episodes occurred in tunneled jugular catheters. However, from an epidemiological standpoint, this does not necessarily imply a higher risk, as these are also the most frequently used catheters in the unit. "Tunneled jugular catheters were the most common vascular access in the recorded infection episodes."

Conclusions: Prophylactic gentamicin locking was associated with a significant reduction in CVC-related infections in hemodialysis patients. Gram-negative bacilli were the predominant microorganisms, with Escherichia coli and Enterobacter spp. being the most frequently isolated agents. Poor personal hygiene and prolonged catheter dwell time emerged as significant risk factors. These findings support the continued use of the gentamicin locking protocol as an effective prevention strategy in hemodialysis units.