Time-Dependent Contamination of Opened Sterile Operating-Room Trays

SLR - January 2010 - Dee Gordon McCrary

Reference: 
Dalstrom, D.J., Venkatarayappa, I., Manternach, A.L., Palcic, M.S., Heyse, B.A., and Prayson, M.J. (2008) Time-dependent contamination of opened sterile operating-room trays.  The Journal of Bone and Joint Surgery (American), 90, 1022-1025.

Scientific Literature Reviews

Reviewed by:  Dee Gordon McCrary III, DPM
Residency Program: Kaiser North Bay Consortium, Vallejo

Podiatric Relevance:
There are many factors involved in combating surgical infection.  The maintenance of sterility of surgical equipment and implants is an important way to reduce the incidence of surgical infection.  This article examines the rate of time-dependent contamination of sterile trays opened in a controlled operating-room environment. 

Methods:
In this controlled study, forty-five sterile trays were opened in a positive-air-flow operating room, and randomly placed into three groups:  (1)open in a locked operating room, (2)open with one-person traffic every 10 minutes from a nonsterile corridor, and (3)opened but covered immediately with a sterile surgical towel in a locked operating room.  Culture specimens were taken immediately after opening and at thirty minute intervals over the course of four hours.

Results: 
The covered trays were not contaminated during the testing period. The contamination rates recorded for the twenty-seven uncovered trays were 4% (one tray) at thirty minutes, 15% (four) at one hour, 22% (six) at two hours, 26% (seven) at three hours, and 30% (eight) at four hours. There was no difference in survival time (p = 0.47) or contamination rate (p = 0.69) between the uncovered trays in the room with traffic and those in the room without traffic. Three were found to be contaminated immediately after opening and were subsequently eliminated.  Common skin flora was the predominant source of contamination.

Conclusions:
This article emphasizes the importance of minimizing the exposure of sterile equipment to open environments, even in low-traffic areas.  The study suggests that the rate of contamination correlates directly with the time of exposure.