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Is retained bone debris in cannulated orthopedic instruments sterile after autoclaving?
Kenneth Smith1, Ibukunoluwa Araoye1, Shawn Gilbert1
1University of Alabama at Birmingham, Birmingham, AL.
Aims:
Cannulated surgical instruments may retain biologic debris after routine cleaning and sterilization. Residual debris after cleaning is assumed to be sterile; however, there is no experimental basis for this assumption. The purpose of this study was to determine the sterility of retained biodebris found within cannulated surgical instruments after autoclave sterilization.
Materials And Methods:
Fifteen cannulated drill bits were used to drill pig scapulae to create a plug of bone that was exposed to a mixture of Bacillus cereus, Pseudomonas aeruginosa, and methicillin-resistant Staphylococcus aureus for 60, 120, or 180 minutes prior to sterilization. The drill bits were autoclave sterilized using standard settings. The "sterilized" bone cores were then incubated in solution and streak-plated on blood agar.
Results:
All 3 positive controls were positive for the experimental bacteria. Two negative controls were positive for contaminant bacteria. A B. cereus strain was recovered from 1 of the experimental group drill bits in the 180-minute group. Pulsed-field gel electrophoresis confirmed that the recovered B. cereus strain was identical to the experimental inoculate.
Conclusion:
Retained biodebris in cannulated drills may not be sterile after standard autoclave sterilization. In addition, delay of surgical instrument reprocessing may increase the risk of resistant contamination.
Insights
Surgical instruments with retained debris may not be sterile after autoclaving. Delays in reprocessing cannulated instruments increase the risk of bacterial contamination, compromising patient safety.
Area of Science:
- Microbiology
- Surgical Instrument Reprocessing
- Sterilization
Background:
- Cannulated surgical instruments can retain biologic debris post-cleaning.
- The sterility of residual debris after sterilization is often assumed but lacks experimental validation.
Purpose of the Study:
- To determine if retained biodebris within cannulated surgical instruments is sterile after standard autoclave sterilization.
Main Methods:
- Cannulated drill bits were contaminated with a bacterial mixture (Bacillus cereus, Pseudomonas aeruginosa, MRSA).
- Drill bits were subjected to standard autoclave sterilization.
- Bone cores from contaminated drill bits were incubated and cultured to assess bacterial viability.
Main Results:
- A Bacillus cereus strain, identical to the experimental inoculate, was recovered from a drill bit exposed for 180 minutes.
- Positive controls confirmed experimental bacteria viability, while negative controls showed contamination.
Conclusions:
- Retained biodebris in cannulated surgical instruments may remain non-sterile after autoclave sterilization.
- Delayed reprocessing of surgical instruments elevates the risk of resistant bacterial contamination.
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