OTA 2006 Posters
Scientific Poster #81 Basic Science
Time-Dependent Contamination of Opened Sterile Trays
David J. Dalstrom, MD (n); Indresh Venkatarayappa, MD (n);
Alison L. Manternach, RN, MSA (n); Marilyn S. Palcic, PA-C (n);
Beth A. Heyse, RN (n); Michael J. Prayson, MD (n);
Wright State University and Miami Valley Hospital, Dayton, Ohio, USA
Purpose: Our objective was to determine the time-dependent risk of
contamination for opened sterile trays in the operative setting.
Methods: A total of 45 sterile trays were opened in a positive-air-flow
operating room for 4 hours. 15 trays had single-person traffic flowing in
and out of the room every 10 minutes (traffic); 15 trays were left in a
locked room where no doors were opened while the study was in progress (no
traffic); and 15 trays were without traffic (doors locked) and covered with
a sterile blue surgical towel (covered, no traffic). Using sterile technique,
tray cultures were taken upon opening and every 30 minutes for 4 hours.
Bacterial and fungal plates were used as the air quality control.
Results: Upon opening, three (10%) of the 30 uncovered trays were
immediately contaminated (one, traffic; two, no traffic). After eliminating
those three trays, the following contamination rates and times were recorded
for uncovered trays: 4% (1 of 27) at 30 minutes, 15% (4 of 27) at 1 hour,
22% (6 of 27) at 2 hours, 26% (7 of 27) at 3 hours, and 30% (8 of 27) at
4 hours. Of the positive cultures, 44% were coagulase-negative staphylococcus,
22% corynebacterium, and 34% other bacteria. There was no difference in
mean survival time (P = 0.47) and contamination rate (P =
0.69) between the uncovered trays with traffic versus those without traffic.
The 15 covered trays experienced no contamination over the 4-hour testing
period. Their mean survival time (P = 0.03) was significantly higher
and contamination rate (P = 0.02) significantly lower than the uncovered
trays with and without traffic. In all three groups tested, the air quality
bacterial plates were positive and the fungal plates were negative.
Conclusion/Significance: Situations arise (such as a delay to the
start of an operation or multiple procedures in the same operative setting)
in which sterile trays are opened but not immediately used. No clear guidelines
exist on how long a sterile tray can be exposed to the open environment
before contamination risk becomes unacceptable. Based on the findings of
this study, the sterilization process did not necessarily produce absolute
sterility, even when parameters confirming sterilization had been reached.
Culture positivity correlated with the time of open exposure for uncovered
trays. Traffic had no significant bearing on contamination risk. Simple,
practical sterile towel coverage of surgical trays significantly reduced
contamination risk. Every effort should be made to reduce the exposure of
sterile trays prior to use in an effort to decrease contamination potential.
Sterile trays should not be opened until specifically needed during the
procedure. However, if a tray is opened but not immediately used, sterile
towel coverage is recommended to minimize exposure to environmental contaminants.
If noted, the author indicates something of value received.
The codes are identified as a-research or institutional support; b-miscellaneous
funding; c-royalties; d-stock options; e-consultant or employee; n-no conflicts
disclosed, and *disclosure not available at time of printing.
·
The FDA has not cleared this drug and/or medical device for the use
described in this presentation (i.e., the drug or medical device is being
discussed for an "off label" use). · · FDA
information not available at time of printing.