Differences in microorganism growth on various dressings used to cover injection sites: inspection of the risk of catheter-related bloodstream infections caused by Gram-negative bacilli.

Purposes: Sepsis caused by Gram-negative bacilli (GNB) is the most serious catheter-related bloodstream infection. However, the cause(s) of GNB propagation on the skin around needle or catheter insertion sites remain unclear. This observational study aimed to assess the differences in the microbial growth among various types of dressings used to cover injection sites, with a particular focus on GNB.

Methods: We analyzed the bacterial populations on three types of surgical dressings; Tegaderm I.V. (semi-permeable, 27 sheets), IV3000 (highly permeable, 34 sheets) and Tegaderm CHG (chlorhexidine-impregnated, 26 sheets). The peripheral catheter site dressing was replaced every 3 days or when there was leakage or pain at the catheter site.

Results: Bacterial growth was observed in all Tegaderm I.V. and IV3000 sheets and in only one (3.8%) Tegaderm CHG sheet. The GNB detection rate was significantly lower in the IV3000 group (2.9%) than in the Tegaderm I.V. group (63.0%). No GNB growth was identified in the Tegaderm CHG group.

Conclusions: Semi-permeable dressings were insufficient to prevent GNB infections, whereas highly permeable or chlorhexidine-impregnated dressings could prevent GNB infections. Chlorhexidine-impregnated dressings can control almost all bacterial growth.