EPIDURAL CATHETER RECONNECTION - SAFE AND UNSAFE PRACTICE

Background: An in vitro model of epidural catheter contamination was u sed to determine if disconnected catheters can be safely reconnected. Methods: Epidural catheters were filled with brain-heart infusion (BHI ) broth or preservative-free saline containing 5 mu g/ml fentanyl. Esc herichia coli, Pseudomonas aeruginosa, or Staphylococcus aureus (1 . 1 0(5) colony-forming units) was injected into the initial 1.1 +/- 0.24 inch (2.75 +/- 0.60 cm) of the catheters. To study the effect of bacte ria settling in a vertically oriented catheter on the advancement of b acteria along the catheter, bacteria were incubated with catheters in the vertical and the horizontal positions. To determine if bacteria ar e swept further into a catheter when fluid in it is displaced, cathete rs were inclined 30 degrees and the fluid in them was allowed to drain from the distal end to various extents. Bacteria were incubated with the catheter held horizontally. After incubation, the catheters were s erially sectioned, and the resulting segments were eluted with buffere d saline-containing gelatin (BSG), which was collected on BHI agar pla tes for colony counts. This determined if a segment of the catheter re mained internally sterile distal to the point of disconnection. Effect iveness of decontaminating the exterior of the catheter was also teste d as follows: Catheters (n = 10) were first immersed in BSG containing 1 . 10(8) S. aureus, immediately immersed in betadine for 2 min, expo sed to air for 3 min, cut with a sterile instrument, and reconnected t o a sterile screw cap catheter connector. Reconnected catheters were p erfused with 10 mt BSG for 1 hr. Collected perfusate (100 mu 1) was re moved for direct colony count; the remaining perfusate was mixed with an equal volume of BHI and incubated overnight A 100-mu 1 aliquot of B HI-BSG mixture was sampled the next day. No bacteria were cultured fro m either the perfusate or BHI-BSG mixture. Results: Eight hours after contamination, as long as the fluid in the catheter was static, no bac teria were detected more than 13 inches (32.5 cm) from the contaminate d end of catheters filled with BHI and no more than 8 inches (20 cm) f rom the end of those filled with fentanyl solution. This finding was n ot affected by incubation of the catheter in the vertical position. Fl uid displacement less than 8 inches (20 cm) had no effect on dissemina tion, but when fluid was displaced 13 inches (32.5 cm), bacteria were found at the end of the catheter, 35 inches (87.5 cm) away. No bacteri a were recovered from the perfusate of reconnected catheters after the catheters were cleaned with betadine and cut with a sterile instrumen t. Conclusions: There may be an area distal to the disconnected end of an epidural catheter where its interior remains sterile for at least 8 hr. Such an area exists only when the fluid in the catheter remains static. Furthermore, the exterior of the catheter can be adequately cl eaned to prevent bacteria from entering the catheter when reconnected at that point.