Operating Room Improvements Based on Environmental Quality Index Risk Prediction can help Reduce Surgical Site Infections

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Jennifer Wagner, PhD, CIC Thomas Gormley, PhD Troy A. Markel, MD Damon Greeley, PE


Importance: The role of the operating room (OR) airborne environment in the incidence of surgical site infections (SSI) has ranked behind patient and perioperative team-related factors associated with risk for SSI. Emerging evidence demonstrates that the design and performance of the OR environment impacts the airborne microbiome both within the sterile field and at tables where instruments and implants are exposed. However, the correlation between OR air quality and the risk of SSI continues to be challenged.

Objective: To determine if improving the asepsis of the airborne environment in ORs contributes to reduced SSI rates.

Design: The performance of air delivery systems in fourteen operating rooms was evaluated using the Environmental Quality Indicator (EQI) risk picture method to identify potential improvements to airflow management that reduce airborne contamination and operating costs. SSI rates for colon and abdominal hysterectomy procedures were tracked in these ORs for 39 months before and after improvements were implemented. SSI rates were also tracked for the same time frame for six control ORs in which no improvements were made. Airborne microbial data was collected.

Setting: Twenty ORs in an academic medical center, Midwest USA. A convenience sample of all surgical patients, de-identified, was used in the twenty ORs studied.

Results: SSI rate was reduced from 8.4% to 5.7% (p=.0039) in ORs in which improvements were implemented. Reduction of SSI rate in control ORs was not significant (p=.76). Fewer airborne microbes were detected in areas of OR with improvements (p<.0001).

Conclusion: Areas for environmental quality improvement in ORs was identified and mapped by relative risk of contamination. Implementation of these improvements resulted in decreased microbial contamination and contributed to significant reduction in surgical site infection.

Keywords: Surgical site infection, SSI, Environmental Quality Indicators, EQI, Risk, Contamination, Operating Room

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How to Cite
WAGNER, Jennifer et al. Operating Room Improvements Based on Environmental Quality Index Risk Prediction can help Reduce Surgical Site Infections. Medical Research Archives, [S.l.], v. 10, n. 10, oct. 2022. ISSN 2375-1924. Available at: <https://esmed.org/MRA/mra/article/view/3179>. Date accessed: 19 june 2024. doi: https://doi.org/10.18103/mra.v10i10.3179.
Research Articles


1. Magill SS, Edwards JR, Bamberg W, et al. Multistate point-prevalence survey of health care-associated infections. New Engl J Med. 2014;370(13):1198-1208.
2. Kurtz SM., Lau E., Watson H., et al. Economic burden of periprosthetic joint infection in the United States. J Arthroplasty. 2012;27:61-65.
3. de Lissovoy G, Fraeman K, Hutchins V, et al. Surgical site infection: Incidence and impact on hospital utilization and treatment costs. Am J Infect Control. 2009;37(5): 387-397.
4. Condon RE, Schulte WJ, Malangoni MA, Anderson-Teschendorf MJ. Effectiveness of a surgical wound surveillance program. Arch Surgery. 1983;118(3):303-307.
5. Centers for Disease Control and Prevention. 2019. US Department of Health and Human Services. https://www.cdc.gov/infectioncontrol/guidelines/index.html. Accessed September 2019.
6. World Health Organization. 2019. Global Guidelines on the Prevention of Surgical Site Infections. https://www.who.int/infection-prevention/en/. Accessed September 2019.
7. US Department of Health and Human Services, AHRQ Patient Safety Network. 2019. https://psnet.ahrq.gov/primers/primer/45/surgical-site-infections. Accessed September 2019.
8. Association for Professionals in Infection Control. APIC Implementation Guide: Infection Preventionist’s Guide to the OR. http://apic.org/Resource_/TinyMceFileManager/Implementation_Guides/APIC_ImplementationPreventionGuide_Web_FIN03.pdf. Accessed September 2019.
9. Association of peri-Operative Surgical Nurses. Guidelines for Perioperative Practice. 2019. AORN, Inc. ISBN:MAN-019. Accessed September 2019.
10. Ban KA, Minei JP, Laronga C, et al. American College of Surgeons and Surgical Infection Society: Surgical Site Infection Guidelines, 2016 Update. DOI: https://doi.org/10.1016/j.jamcollsurg.2016.10.029
11. Berrios-Torres, SI, Umscheid CA, Bratzler DW. Centers for Disease Control and Prevention Guide-line for prevention of Surgical Site Infection, 2017. JAMA Surg. 2017;152(8):784-791.
12. ASHRAE. Ventilation of healthcare facilities (Standard170-2017). 2017.
13. Memarzadeh F, Weiren XU. Role of Air Changes per hour (ACH) in possible
transmission of airborne infections. Build Simul. 2012;5:15-28.
14. Agency for Healthcare Research and Quality. Patient Safety Network. Surgical Site Infections. https://psnet.ahrq.gov/primer/surgical-site-infections?q=/primers/primer/45. Accessed September 2019.
15. Darouiche RO, Green DM, Harrington MA, et al. Association of airborne microorganisms in the operating room with implant infections: a randomized controlled trial. Infect Control Hosp Epidemiol. 2017;38:3-10.
16. Knobben BAS, Engelsma Y, Neut D, et al. Intraoperative contamination influences wound discharge and periprosthetic infection. Clin Orthop. 2006;452:236-241.
17. Davis N, Curry A, Gambhir AK, et al. Intraoperative bacterial contamination in operations for joint replacement. J Bone Joint Surg Br. 1999;81:886-889.
18. Gormley T, Greely D, Markel T, et al. Cost –Benefit Analysis of Different Air Change Rates in an Operating Room Environment. Am J Infect Control. 2017;45:1318-1323.
19. Wagner J, Gormley T, Greeley D, et al. EQI Method to Compare Air Delivery Methods in Functional ORs During Dynamic Simulated Surgical Procedures. Am J Infect Control. 2018. DOI https://doi.org/10.1016/j.ajic.2018.07.020
20. Gormley T, Greely D, Wagner JA, et al. Methodology for Analyzing Environmental Quality Indicators (EQIs) in a Dynamic Operating Room Environment. Am J Infect Control. 2017;24: 354-359.
21. Markel T, Gormley T, Greeley D, et al. Covering the Instrument Table Decreases Bacterial Bioburden: An Evaluation of Environmental Quality Indicators. Am J Infect Control. 2018. DOI: https://doi.org/10.1016/j.ajic.2018.02.032.
22. Markel T, Gormley T, Greeley D, Ostojic J, and Wagner J. Hats Off: A Study of Different Operating Room Headgear Assessed by Environmental Quality Indicators. J Am Coll Surg. 2017a;225 (5):573-581.
23. Markel T, Gormley T, Greeley D, et al. Wearing long sleeves while prepping a patient in the operating room decreases airborne contaminants. Am J Infect Control. 2017b. DOI: https://doi.org/10.1016/j.ajic.2017.10.016
24. International Organization for Standardization. ISO 14644-1. 2017.
25. Birgand G, Toupet G, Rukly S, et al. Air contamination for predicting wound contamination in clean surgery: a large multicenter study. Am J Infect Control. 2015;43(5):516-521.
26. Howorth FH. Prevention of airborne Infections in operating rooms. Hosp Eng. 1986;40(8):17-23.
27. Howorth FH. Prevention of airborne infection during surgery. Lancet. 1985;1(8425):386-388.
28. Lidwell OM, Lowbury EJ, Whyte W, et al. Effect of ultraclean air in operating rooms on deep sepsis in the joint after total hip or knee replacement: a randomized study. Br Med J. 1982;285(6334):10-14