206 Reducing Surgical Instrument Bioburden through Intra-lumen Video Imagery- What You Can't See May Hurt You

Friday, March 19, 2010
Grand Hall (Hyatt Regency Atlanta)
Lisa Sturm, MPH, CIC , University of Michigan Health System, Ann Arbor, MI
Jahan Azizi, CBET , University of Michigan Health System, Ann Arbor, MI
Julia Jackson, CST, MEd, FAST , University of Michigan Health System, Ann Arbor, MI
Karen Bett, MT(ASCP), CSPDS , University of Michigan Health System, Ann Arbor, MI
Susan Anderson, MSN, MBA, CPHRM , University of Michigan Health System, Ann Arbor, MI
Shawn Murphy, RN, BSN, MS , University of Michigan Health System, Ann Arbor, MI
Carol Chenoweth, MD , University of Michigan Health System, Ann Arbor, MI


Background:   Bioburden on instruments can interfere with complete sterilization of instruments and therefore presents a potential risk to subsequent patients. Our institution has been working aggressively to reduce bioburden found on surgical instruments to zero. 

Objective:   To assess the effectiveness of manufacturer's recommendations for cleaning and to optimize decontamination protocols for reducing bioburden on instruments through use of an endoscope to view the internal lumens of the instruments.

Methods:   A 2.7 mm endoscope was passed into the lumen of instruments taken from reprocessed sterile surgical trays over a 3 week period in 10/09.  Problem-prone trays were selected based on history of bioburden (Otolaryngology, Neurosurgery (NS), and Orthopedic).   Those instruments with bioburden were analyzed again with the endoscope following manufacturer's cleaning recommendations using various size brushes, soaking for various periods of time in enzymatic detergent and/or cycling for various amounts of time in the ultrasonic machine. (Table)  Bioburden was verified using a blood residue test kit. 

Phase 1:  144 suction tips from 12 NS trays analyzed.  

Phase 2:  350 suction tips from 36 trays analyzed.

Phase 3:  16 suction tips/shavers from 8 trays processed as in Phase 2, using wire brushes to clean the lumens (versus manufacturer's recommended nylon bristle brushes).

Results: A total of 56 trays containing 510 lumened instruments were analyzed over the three phases of the experiment.

Phase 1:

Cleaning Protocol

# instruments with  Bioburden/Foreign Matter (%)

Taken from inventory shelf


144 (100%)

After Routine decontamination (N=144)

108 (75%)

After additional soaking .78% enzymatic detergent x 20 min. (N=108)

70 (65%)

After additional 1 cycle in ultrasonic machine (N=70)

42 (60%)

After additional soak in enzymatic x 20 min and x  2 cycles in ultrasonic (N=42)


After repeated soaking in enzymatic x 20 min., x 1 ultrasonic, re-brushing (N=21)

17 (80%)

Soaked overnight in concentrated enzymatic (N=17)

17 (80%)

Phase 2:  350 (100%) of the suction tips analyzed contained bioburden/foreign matter inside the lumens upon first inspection.  333 (95%) remained contaminated after following manufacturer's recommendations for reprocessing.  

Phase 3:  All 16 (100%) suctions tips had traces of bioburden/foreign matter remaining after cleaning with the wire brushes.  


Conclusions: The design of surgical instruments, especially those with lumens, can make cleaning, and sterilization difficult to accomplish.  Users should refer to the manufacturer's recommendations for instrument reprocessing; however, inapparent bioburden may still be present.  Instrument manufacturers need to take into account ease of cleaning and sterilization in their design standards for maximum patient safety.