Relative Efficacy of Commercially Available Ultraviolet-C Devices in the United States With Sufficient Irradiation Dose Delivery to Horizontal Surfaces

Background: Improved environmental cleaning in the anesthesia workspace is indicated to reduce surgical site infections. We evaluated the time for delivery of a mean (standard deviation) of 27 (0.15) mJ/cm2, the minimally effective irradiation dose required for attenuation of Staphylococcus aureus multilocus sequence type 5, to radiometers positioned horizontally on the anesthesia machine tray and medication cart using commonly employed ultraviolet-C (UV-C) technology. Methods: This was a multicenter, controlled (by standardized equipment positioning) simulation study evaluating triangular (Helios, Surfacide, Waukesha, WI 53186) and single emitter (Tru-D, Memphis, TN 38104, and Xenex San Antonio, TX 78216) UV-C configurations. A series of standardized UV-C treatment trials was completed for each device. Following manufacturer recommendations and typical use, treatment duration was five minutes for Xenex and up to 30 minutes for Helios and Tru-D devices. The primary outcome was the cumulative maximal irradiation dose delivered to calibrated radiometers positioned horizontally on the anesthesia machine and cart. The trials were fully independent replications. Results: Xenex achieved 27 mJ/cm2 at the anesthesia machine and cart for 1/16 trials and 0/16 trials, respectively. TruD achieved a total of 27 mJ/cm2 at the anesthesia machine within five minutes for 16/16 trials and at the anesthesia cart within 30 minutes for 0/16 trials. Helios achieved 27 mJ/cm2 at the anesthesia machine for 4/8 trials by five minutes and 8/8 trials by 16.2 (3.10) minutes and at the anesthesia cart for 0/8 trials within five minutes and 8/8 trials within 16.2 (3.10) minutes. The proportion of trials achieving the target dose differed significantly between devices (0/16 for Xenex, 0/16 for Tru-D, and 8/8 for Helios). Pairwise comparisons showed that Helios performed significantly better than both other devices (adjusted P < 0.0001 for each comparison). Conclusion: The Helios device can deliver the minimally effective dose of 27 mJ/cm2 to horizontal surfaces within a 30-minute treatment period, which is feasible for the perioperative arena.