Impact of in-line filters and risk factors on catheter-related bloodstream infection in parenteral nutrition.

BACKGROUND

Catheter-related bloodstream infections (CRBSIs) represent approximately 15% of healthcare-associated infections and up to 40% of nosocomial bacteraemia cases. In-line filters are widely used to remove particles, air, and micro-organisms from infusion lines. However, their effectiveness in preventing infections remains uncertain. This study evaluated the association between in-line filter use and CRBSI and identified risk factors in patients receiving parenteral nutrition (PN).

METHODS

We retrospectively reviewed adults who received PN at Mie University Hospital between June 2020 and May 2025. Patients aged ≤18 years or those receiving PN other than Elneopa®, Fulcalic®, or Bifreed® were excluded. CRBSI rates were compared between patients with and without online filters. χ2 and unpaired t-tests were used to assess risk factors, and decision tree analysis examined predictor hierarchies.

RESULTS

Baseline characteristics were comparable between the groups among 862 patients. The incidence of CRBSI was reduced in patients who used in-line filters (P < 0.001). Prolonged PN infusion duration, absence of in-line filter use, and intensive care unit (ICU) admission were significant risk factors for CRBSI. Decision tree analysis identified in-line filter use, infusion duration, and ICU admission as key determinants, with ICU admission plus prolonged infusion forming the highest-risk branch.

CONCLUSION

In-line filters were associated with reduced CRBSI, indicating potential benefit in preventing infusion-related contamination. However, ICU admission and prolonged infusion remained strong predictors, demonstrating that filters alone are insufficient in high-risk settings. Overall, filters may complement broader infection control measures, and further prospective studies are needed to confirm efficacy and cost-effectiveness.