Are Intra-operative Forced Air Warming Devices a Possible Source for Contamination During Hand Surgery?

Background Forced air warming (FAW) devices are routinely utilized in operating rooms for patient temperature control. However, there have been some controversy and conflicting evidence on whether they are a possible source of surgical site infections (SSIs) and contamination. Methods A total of 144 petri dishes were randomized to either a control or experimental group (72 in each group). Each trial consisted of six petri dishes in three locations (floor, table, and operative limb). Two dishes at each location were closed sequentially at one hour, two hours, and three hours. Two control and two experimental trials were performed in two separate operating suites with two different FAW devices. The petri dishes were then analyzed for growth for 48 hours. Two culture swabs from each FAW device hose were obtained and analyzed. Results None of the culture swabs analyzed showed any growth on blood or chocolate agar culture media. There was no significant difference in bacterial colony-forming units per cubic meter (CFU/m) air between the trial and control groups in each location at one hour of exposure. At two hours of exposure, there was a significantly higher bacterial CFU/m air in the experimental group in the operative limb. At three hours of exposure, there was a significantly higher bacterial CFU/m air in the experimental group on the floor. However, overall, there was no difference in bacterial CFU/m air in both study groups at different times of exposure, incubation, or location. Conclusion Our study was unable to identify any statistically significant risk of contamination associated with the use of FAW devices. However, our study design was limited due to the absence of operating room staff during testing. For this reason, we recommend further research into this topic with the use of an active operating room, which includes simulated movement from the surgeon, anesthesia, scrub technician, nursing, and any other operating room staff who may be present during a real operation.