Infection Control Today

SEP 2018

ICT delivers to infection preventionists & their colleagues in the operating room, sterile processing/central sterile, environmental services & materials management, timely & relevant news, trends & information impacting the profession & the industry

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Page 26 of 44

26 ICT September 2018 feature By Russell Nassof, JD; Kathy Warye; and Maureen Spencer, MEd, RN, CIC, FAPIC O ver the last decade, considerable effort and investment has been made in decontamination of the patient environment however, almost all of this focus has been on hard surfaces. Despite evidence of the contribution of contaminated air to healthcare-associated infections (HAIs) and the symbiotic relationship between contam- inated air and bioburden on surfaces, hospital air quality has not been a high priority from a risk mitigation perspective. 1 This is likely due to a combination of factors including: the technical diffi culty of measuring the airborne bioburden; the absence of technological innovation in the air decontamination space; and the ongoing debate about the relative contribution of contaminated air to HAI. With a growing body of evidence correlating aerosolized bacteria and HAI (and surgical site infections (SSIs) in particular), along with the advent of air decontamination technologies that make reduction in airborne bioburden both technically and economically feasible, institutions should have increasing reason to revisit air quality management beginning with the operating room (OR). Nowhere is the risk to patient s of airborne bioburden greater than in the operating room. The recent outbreaks of Mycobacterium chimaera from contaminated heater cooler devices occurred despite proper OR ventilation. The transmission of invasive infection to these patients highlights both the potential for airborne contaminants to cause SSIs and the limitations of current approaches to mitigating airborne transmission. 2 This paper focuses on how the evidence-based legal standard of care can be used to help support adoption of new technologies proven to reduce airborne pathogens in the quest to reduce SSIs and why airborne bioburden in the OR merits greater attention. We have chosen to focus on SSIs in orthopedic surgery where procedural volume is high and rapidly growing and where the clinical and economic consequences of infection are signifi cant. The Contribution of Contaminated Air to SSI As early as 1971, Brachman estimated that airborne transmission was responsible for 10 percent to 20 percent of all endemic hospital-acquired infections. 3 Where SSI in particular is concerned, evidence of the relationship between airborne pathogen levels in the OR and surgical site infection (SSI) continues to emerge: • Kundsin concluded that airborne transmission accounted for 20 percent to 24 percent of post- operative wound infections. 4 • Researchers at the University of Glasfow analyzed the relationship between the number of bacteria washed from the wound at the end of an operation to both the number of bacteria in the OR air and those on the patient's skin at the wound site. They concluded that the most important and consistent route of surgical wound contamination was airborne. 5 • Infection rates in joint replacement surgery have been correlated with airborne concentrations of bacteria near the wound. 6 • Dharan and Pittet found that the risk of contaminated air to SSI increases as airborne microbial counts exceed 36 to 150 colony-forming units (CFUs) per m3 of sampled air. 7 The discovery of Mycobacterium chimaera infections among cardiac surgery patients in 2015-16 were found to be epidemiologically linked to aerosolized bacteria from heater- cooler units contaminated during the manufacturing process. 8 More than 250,000 heart bypass procedures using heater-cooler machines are performed in the U.S. each year. It was estimated that approximately 60 percent of these patients were exposed to contaminated devices. These infections occurred despite adherence to current OR air ventilation standards. Moreover, air sampling studies may actually underestimate the risk of airborne bacteria, as many airborne organisms are diffi cult to culture and therefore may go undetected. 9 The Mycobacterium species falls into this category. Contaminated Air and Prosthetic Joint Infection Our focus on SSIs (prosthetic joint infections [PJI] in particular) is based upon evidence that surgeries involving implants have signifi cantly higher rates of HAIs along with predictions of explosive growth in hip and knee replacement surgeries as the US population ages. PJIs are also among the most economically and clinically conse- quential HAIs.The volume of procedures with prosthetic joint implants is expected to exceed 3.8 million annually by 2030 as a result of the aging population. 10 Studies by Parisi, et al. concluded that the cost of a single PJI could reach nearly $500,000 when personal liabilities and consequential damages, such as lost wages and productivity, are included with basic healthcare costs. 11 As of FY 2018, total hip/knee arthroplasty SSIs are subject to additional penalties under the CMS Readmission Reduction Program. The mortality rate for PJI is also high at 2 percent to 7 percent with a fi ve-year survival rate worse than with many cancers. 12-13 While the incidence rate for PJI is low (<2.5 percent), 14 given the projected rate of growth in procedural volume alone, the aggregate number of PJIs could reach close to 1 million infections by 2030. There is considerable evidence of a close correlation between infections in joint replacement surgery and airborne bacteria. A prospective randomized multicenter study showed that joint replacement procedures performed in rooms with over 50 CFU/m3 airborne bacterial forming units were 2.6 times more likely to have postoperative SSIs than those done in cleaner air with 20 CFU/m. 15 PJI has also been correlated with concentrations of bacteria near the wound. 16 Airborne particles including dust, textile fi bers, skin scales, and respiratory aerosols loaded with viable microorganisms (including Developing the Case for Implementation of Operating Room Air Decontamination Technology for Orthopedic Surgery

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