Epidural Filters and Particles from Surgical Gloves

Abstract

Placement of filters in epidural catheters has been recommended in order to prevent particles and bacteria from reaching the epidural or spinal spaces, as well as peripheral nerves, during the performance of regional or peripheral blockade. The aim of placing filters is to prevent contamination during drug administration, with the subsequent spread of infection along meningeal layers or peripheral nerves. These filters have filtering membranes composed of micropores with variable surface areas that filter particles and bacteria present in substances injected through the epidural catheters. During preparation of local anesthetic infusions, it is possible to introduce contaminant agents such as small particles present in surgical gloves or minute fragments from glass ampoules. Recommended filters for epidural catheters in regional and peripheral blockade include labels such as “Porosity 0.2 μm,” referring to the pore size and therefore to the minimum size of particles (including bacteria) that will be retained by the filtering membrane.