Influence of protective measures after epidural catheter disconnection on catheter lumen colonization: an in vitro study.

Background: Epidural anaesthesia provides excellent pain therapy and reduces postoperative morbidity and mortality. Epidural haematoma and infection are catastrophic complications of this therapy. Following accidental catheter disconnection the choice is between reconnection and premature treatment termination. There is little experimental or clinical data guiding clinical decision-making after epidural catheter disconnection.

Aim: Investigation of the in vitro effects of clinically applied safety measures after epidural catheter disconnection.

Methods: The proximal 20mm of epidural catheters were submerged into a suspension of 1 × 10(8)cfu Staphylococcus epidermidis. Catheters were treated by the following potentially preventive measures: (i) cutting 2 cm distal to the level of contamination, (ii) disinfection by spray-wipe, or (iii) employing ropivacaine 0.75% as flushing solution instead of normal saline. All measures were used alone, in a dual combination or all together as a triple intervention (N = 10 catheters in each group). Control catheters were not treated. After 24h of culturing, bacterial growth of the eluates was recorded.

Findings: All control catheters showed positive cultures. All 49 eluates of catheters that were cut as a single, dual or triple intervention remained sterile. Disinfection prevented bacterial growth in eluate of only six catheters in single or dual interventions. Ropivacaine did not prevent any bacterial growth.

Conclusion: Only cutting of epidural catheters 20 mm distal to the level of contamination completely prevented bacterial growth. Disinfection might further reduce risk as an additive measure. This supports the clinical practice of catheter shortening and reconnection. The safe window of time and length of shortening needs to be further investigated.