In vitro use of epidural filters for prevention of bacterial infection.

An experiment was conducted to evaluate the efficacy of epidural bacterial filters (pore size 22nm) in the filtration of pathogenic bacteria from clear intravenous (IV) fluids. Fifty mL of sterile dextrose was mixed with a known quantity of bacteria and infused through an epidural bacterial filter by a syringe pump at a rate of 2 ml per hour for 24 hours. Cultures were done from the remaining fluid in the syringe, the filtrate in the urobag, as well as the bacterial solution at the end of 24 hours. The efficacy of the filter against bolus doses was also evaluated. Staphylococcus aureus and Pseudomonas (80cc strain) were chosen. Initial runs conducted without the filters showed that bacteria could be isolated from the syringe and the urobag at the end of 24 hours. The filtrate in all runs and that tested for efficacy against IV bolus dose was sterile. However, four filters in the experiment using bolus doses, got clogged and had to be discarded. The epidural bacterial filter proved 100% effective in removing pathogenic bacteria from clear IV fluids under experimental conditions.