Bacteriologic aspects of epidural analgesia

Area of Science:

• Anesthesiology
• Infectious Disease Prevention
• Obstetrics

Background:

• Epidural analgesia is common in labor but carries a risk of infection.
• Catheter and syringe contamination can introduce bacteria into the epidural space.
• Bacterial filters are used to mitigate infection risk.

Purpose of the Study:

• To investigate contamination rates of catheters and syringes during epidural analgesia.
• To evaluate the effectiveness of bacterial filters in preventing contamination.
• To assess the impact of bupivacaine on bacterial viability.

Main Methods:

• Culturing of catheter tips and syringes used in epidural procedures.
• Testing the bacteriocidal effect of 0.25% bupivacaine on common skin commensals at different temperatures.
• Analysis of contamination sources.

Main Results:

• Syringe contamination occurred in 5/101 cases; catheter tips remained sterile.
• Isolated organisms were skin commensals, likely from personnel contact.
• Bupivacaine demonstrated bacteriocidal effects on S epidermidis and Corynebacterium spp. at 37°C, but not at room temperature.

Conclusions:

• Bacterial filters are effective in preventing catheter contamination during epidural analgesia.
• Using new syringes for each epidural injection is recommended to prevent bacterial seeding.
• Bupivacaine's temperature-dependent bacteriocidal activity may contribute to safety.