Evidence suggesting that microbial aerosols can be responsible for - PDF document

6/16/2018 Air Contamination and SSI Risk: Do We Need a New Standard in an Era of Device - Related Procedures? Charles E. Edmiston Jr., PhD., CIC, FIDSA, FSHEA, FAPIC Emeritus Professor of Surgery - Department of Surgery Medical College of Wisconsin, Milwaukee, Wisconsin USA edmiston@mcw.edu No Conflict of Interest to Report 1

6/16/2018 Discussion Points • The historic role of the operating room (environment of care) as a risk factor for infection • Evidence suggesting that microbial aerosols can be responsible for surgical site infections • Modern air-handling strategies for the operating room environment • Innovative strategies to reduce a proposed risk • Is it time to proposed a standard for microbial airborne burden in the operating room environment • What is the economic consequences in an era of fiscal liability? 2

6/16/2018 “It’s all about the surgical wound” – the primary determinant of “….all surgical wounds are contaminated to some degree at closure whether the contamination is established as a clinical infection is host (wound) defense” Belda et al., JAMA 2005;294:2035 - 2042 Quantitative Risk of Infection Microbial Burden 5 In the Wound (~10 ) x Microbial Virulence = Overall risk of SSI Host resistance (wound defense) A Foreign Body Trumps This Equation 3

6/16/2018 Extrinsic Risk Factor: Bacterial Colonization of Implantable Devices • Implantable Device – Pathogenesis of Infection • Implants provide nidus for bacterial adherence • Bacterial colonization can lead to biofilm formation • Biofilm formation enhances antimicrobial recalcitrance As little as 100 staphylococci can initiate a device - related infection Ward KH et al. J Med Microbiol. 1992;36: 406 - 413. Mangram AJ et al. Infect Control Hosp Epidemiol.1999;27:97 - 134 Edmiston CE, Problems in General Surgery 1993;10: 444 Edmiston CE, J Clinical Microbiology 2013;51:417 The historic role of the operating room ( environment of care) as a risk factor for infection 4

6/16/2018 The “Good Old Days” in the Operating Room 5

6/16/2018 Evidence suggesting that microbial aerosols can be responsible for surgical site infections « The airborne component of postoperative wound infection is not a fixed rate but rather varies from hospital to hospital, from OR "You are villains in a plot to OR, and from surgical team to against your patients. surgical team. The rate is Because of your proportional to the number of negligence, 90 percent of disseminating carriers in the the nation's hospitals are room - aerosol contamination accounts for 20 - 24 % of a menace to health." postoperative infections” Carl W. Walters, MD 6

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6/16/2018 Epidemiology of Total Joint Infections “ The personnel who enter the OR carry the bacteria” Ritter MS., Clin Orthop Relat Res. 1999;369:103 - 109. • Presence of OR personnel - increases shedding by a factor of 40X 20 % to 30% of all OR personnel – Staphylococcus aureus • carriers • “High shedders” (>10,000 bacteria/min): 13 % males 5 % postmenopausal females 1 % premenopausal females 8

6/16/2018 Edmiston et al, AORNJ 1999;69:1169 Seabrook GR, et al. J Vasc Surg. 1990;11:629 - 634 9

6/16/2018 Intraoperative Measurement of Microbial Populations Within the Operating Room 0.45 m m Filter Culture Media Microbial Recovery Incubate 48 hours o o Cascade 35 C (30 C) Impactor IDENTIFICATION 10

6/16/2018 Vascular Operating Room Intake vent Table Intake vent - Cascade Impactor - Colored dots – unique staphylococcal - Personnel strains recovery from anterior nares 3 a 3b 4a 5a 9a 11a MSM 7a 7b 1a 1b 1c 1d Edmiston et al, Surgery 2005; 138; 573 - 582 11

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6/16/2018 Does operating room traffic influence particulate (viable/nonviable) dispersion? 13

6/16/2018 Infect Control Hosp Epidemiol 2018;1 7 – Rezapoor et al, J Arthroplasty 2018;33:851 - 855 14

6/16/2018 Teter J, et al. Am J Infect Control. 2017;45:477 - 482 15

6/16/2018 Modern air - handling strategies for the operating room environment 16

6/16/2018 - Typical “Laminar Flow” Design Used in Most Hospital Operating Rooms Multi - Diffuser Array Single - Large Diffuser Air Curtain Modified from: Dr. Jenifer Wagner, Air Media Magazine, Summer 2014 17

6/16/2018 Goddard, K.R. Factors involved in providing cleaner environment in surgery. Air Engineering, July 1965 18

6/16/2018 • Airflow velocity and microbial load between the back table and sterile field was highly variable among the operating rooms tested. • To date there is no scientific evidence to support that increasing the ventilation rate to a higher levels actually reduces SSIs. • Use of environmental quality indicators (EQI) such as level of microbial contamination, number of particles (non - viable/viable) and air velocity at key point in the operating room may provide a more accurate assessment of risk. Current HVAC systems, including laminar flow and positive pressure systems, do not deactivate microbial aerosols, but displace the microorganisms. Which are continuously being shed within the OR setting, contributing to the airborne (and surface) microbial burden. TURBULENT ZONES KEEP MICROBIAL PARTICLES IN SUSPENSION 19

6/16/2018 Innovative strategies to reduce a proposed risk Marginalizing Air Currents in the Operating Room Environment 20

6/16/2018 Nakajima et al. Eur J Orthop Surg Traumatol 2017;27:1139 - 1143 Oct 21

6/16/2018 Nakajima et al. Eur J Orthop Surg Traumatol 2017;27:1139 - 1143 Young et al. J Arthroplasty 2016;31:225 - 233 22

6/16/2018 Young et al. J Arthroplasty 2016;31:225 - 233 Novel HEPA Filtered Air Delivered to the Surgery Site (Active) Airborne CFUs (viable) “ ……are a likely source of contamination leading to device - related infections.” Darouiche et al. ICHE 2016;1 - 8. 23

6/16/2018 Ultraviolet ( UV - C)/Visible Germicidal Irradiation Novel UV Air Disinfection System (Passive/Active Technology) Maury Regional Hospital Columbia, TN 56 % Reduction 88 % Reduction 24

6/16/2018 • Documented to reduce airborne bacteria levels in operating rooms by 50 - 60 %. • Peer - review: Crystalline UVC was highly effective at significantly ( p<0.05 ) reducing total and viable particle counts related to routine activity within a controlled operating room environment. • Further studies are warranted to assess the risk reduction benefit in TKA and THA orthopedic cases. J Arthroplasty. 2017 Dec 5. pii : S 0883 - 5403(17)31057 - 4 . doi : 10.1016/j.arth.2017.11.052. [ Epub ahead of print Is it time to proposed a standard for microbial airborne burden in the operating room environment? 25

6/16/2018 Number of Airborne Particulates per ISO class Compounding pharmacies must comply with International Standards Organization (ISO) class 5 standards for air quality Air Quality in the OR • The standard (ISO) for airborne contaminants in the “clean room” of a typical semiconductor manufacturer is well defined (ISO Class 1 to Class 4) • These stringent requirements minimize the fiscal loss that is associated with product failure in a highly sensitive manufacturing environment. • The difference in the design of HVAC systems in hospital ORs and facilities designed to meet ISO requirements can be radical. • In the typical OR the arrangement of airflow diffusers over the operating table would not be acceptable to ISO Class 1 to 4. • ASHRAE Standard 170 and AIA guidelines do not represent an evidence-based aerobiological risk-adjusted standard. 26

6/16/2018 Air Quality in the OR • Current guidelines do not address specific criteria for the quantitative reduction of viable microbial aerosols in the OR environment. • The EU has proposed the development of new air quality standards for 1 - 3 the hospital environment based on patient risk. • “There is a direct link between the number of particles in the OR and 4 the number of personnel present in the case.” 1. Charkowska A. J Occup Safety Ergon 2008;14:447 - 453 . 3. Lidwell OM, et al. BMJ 1982;285:10 - 14. 2. Andersson AE, et al. AJIC 2012;40:750 - 755 . 4 . Parvizi et al. AJIC 2017;45:1267 - 1272. 27

6/16/2018 What is the economic consequences in an era of fiscal liability? 28

6/16/2018 Periprosthetic Joint Infections • 2.18% of hip and knee 2 – 7% • Experts report that the five-year implants become infected • Overall lifetime cost for survival rate of patients with PJI a single case of a septic is worse than with most cancers. Historical and projected number of infected THA (age 65) using a THA, TKA, and total (THA + TKA) oneway sensitivity procedures in the United States. analysis of $390,806 per Parisi TJ, et al. Clin Orthop Relat Res. 2017;475:1891-1900 patient. Kurtz et al. J Arthroplasty 2012;27:61-64 • PJI is associated with a mortality rate of between Projected Trends and it is not Pretty 4 Million TJRs by 2030 $3 - 5 Billion* $1.6 Billion* *Projected Cost of PJI Tisosky et al. J Am Acad Orthop Surgeons 2017;1:e34 29

6/16/2018 “It is not the air, it is something in the air” Lister 1861 30