Bacteriological evaluation of the cardiac surgery environment accompanying hospital relocation.

Purpose: Airborne bacteria in the environment are thought to be a cause of postoperative infection. With the relocation of our hospital, the operating room we had used for 35 years was replaced, changing the surgical environment for cardiac operation completely. We conducted this study to evaluate the bacteriological change in the surgical environment between the new and old operating rooms.

Methods: Airborne contaminants in the operating rooms were collected on blood agar plates, and samples of intraoperative salvaged blood from cardiac surgery were drawn from salvaged bags produced by Cell Saver 5 (Haemonetics, Braintree, MA, USA) in both the old (group O) and the new operating rooms (group N). These samples were cultured and evaluated bacteriologically.

Results: We collected nine samples of airborne contaminants from both group O and group N. The mean number of isolated bacteria colonies was 5.0 +/- 1.2 in group O, and 2.0 +/- 0.94 in group N (P < 0.001). Bacterial growth was detected in 85% of the salvaged blood samples from group O (n = 20) versus 60% from group N (n = 15) (P = 0.09). The mean bacteria count was 1.9 +/- 2.7 colony-forming units (cfu)/ml in group O versus 0.4 +/- 0.5 cfu/ml in group N (P = 0.032).

Conclusion: Hospital relocation resulted in an improved operating room environment with less bacterial contamination of intraoperative salvaged blood.