The effect of Indigo-Light Continuous Environmental Disinfection System on Microbial Contamination and SSI in an Orthopedic OR

A growing body of research has demonstrated that manual cleaning and disinfection of the operating room (OR) is suboptimal. Residual environmental contamination may pose an infection risk to the surgical wound. This study evaluates the impact of visible light continuous environmental disinfection system (Indigo-light CED) on microbial surface contamination and surgical site infections (SSI) in an OR. It was performed between Oct 2015 and Oct 2017 at Maury Regional Health Center, a 255-bed regional hospital in Columbia, TN. The hospital has 12 ORs, with 3 dedicated to orthopedic surgery being the ORs of interest in this study. The most common procedures performed in all three ORs are primary joint arthroplasties (total knee>total hip>shoulder>ankle). The use of the Indigo-light CED was designed to be an additional disinfection strategy complementary to the hospital’s standard OR cleaning and disinfection protocol and preexisting SSI bundle. The Indigo-light CED system (Indigo-Clean, Kenall, Kenosha, WI) was installed by the institution in one OR (OR2) on Oct 15, 2016. OR2 is adjacent to another OR (OR1) with which it shares a heating, ventilation, and air conditioning system (HVAC). A third OR (OR3), included in the data analysis for SSIs, was across the hall from ORs1 and 2 and had a separate HVAC system. All three ORs are humidity-controlled and maintained between 66- and 68-degrees Fahrenheit. It is important to note that the deployment and usage of Visible Light CED is very different from portable, UV systems. As it is integrated into the overhead lighting it requires additional considerations related to the center wavelength (per photon efficacy), irradiance (disinfecting power at a point in space) and number of fixtures/layout (disinfecting power throughout the room) to ensure the proper end result. This implies that no two products in this category will be identical, thus the importance of clinical evidence in evaluating their true benefits based upon the manufacturer’s recommended usage. Samples from surfaces within the two contiguous ORs sharing an air supply (OR1 and OR2) were obtained after manual cleaning on multiple days before (Period1) and multiple days after (Period2) Indigo-light CED installation in OR2 only. Samples were incubated and enumerated as total colony-forming units (CFU). SSIs in both OR1 and OR2 and a distant OR (OR3) were tracked for one year prior to and one year after Indigo-light CED installation. There was an 81 (p-value=0.017) and 49 % (p-value=0.015) reduction in total CFUs after Indigo-light CED installation in the OR in which the system was installed and the contiguous OR, respectively. In the OR with the Indigo-light CED, SSIs decreased from 1.4% in the year prior to installation to 0.4% following installation (p-value=0.029). Indigo-light CED, used in conjunction with manual cleaning, resulted in significant reductions in both microbial surface contamination and SSIs in the OR.