Association of Airborne Microorganisms in the Operating Room with Implant Infections: A Randomized Controlled Trial

OBJECTIVE To evaluate the association of airborne colony-forming units (CFU) at incision sites during implantation of prostheses with the incidence of either incisional or prosthesis-related surgical site infections. DESIGN Randomized, controlled trial. SETTING Primary, public institution. PATIENTS Three hundred patients undergoing total hip arthroplasty, instrumented spinal procedures, or vascular bypass graft implantation. METHODS Patients were randomly assigned in a 1:1 ratio to either the intervention group or the control group. A novel device (Air Barrier System), previously shown to reduce airborne CFU at incision sites, was utilized in the intervention group. Procedures assigned to the control group were performed without the device, under routine operating room atmospheric conditions. Patients were followed up for 12 months to determine whether airborne CFU levels at the incision sites predicted the incidence of incisional or prosthesis-related infection. RESULTS Data were available for 294 patients, 148 in the intervention group and 146 in the control group. CFU density at the incision site was significantly lower in the intervention group than in the control group (P<.001). The density of airborne CFU at the incision site during the procedures was significantly related to the incidence of implant infection (P=.021). Airborne CFU densities were 4 times greater in procedures with implant infection versus no implant infection. All 4 of the observed prosthesis infections occurred in the control group. CONCLUSION Reduction of airborne CFU specifically at the incision site during operations may be an effective strategy to reduce prosthesis-related infections. Trial Registration: clinicaltrials.gov Identifier: NCT01610271.