Healthcare Hygiene magazine November 2019 | Page 33

patient safety & quality
By Kathy Warye
Is It Time to Rethink Air Quality in the OR?
O
ver the last decade, U.S. healthcare institutions have
made significant strides in reducing healthcare-as-
sociated infection (HAI) through a combination of vertical
strategies, targeted toward the reduction of device or
organism specific infection and horizontal strategies aimed at
mitigating infection risk across the continuum of care. Strong
financial incentives established as part of the Affordable
Care Act continue to pressure hospitals to find new ways
of reducing HAIs. Despite these measures, HAIs continue
to be among the most prevalent and costly adverse events
in US healthcare institutions. 1
In 2010, Weber, et al. found that in the case of several
of the more critical organisms present in hospitals, that
patient-to-patient transmission was directly proportional to
the level of environmental contamination. 2 The emergence
of MDROs that persist in the environment, combined with
a growing body of evidence correlating contaminated
surfaces to HAI, heightened awareness of the environment
as a transmission risk in institutions.
As a result, cleaning and disinfection of the patient
environment became a core, horizontal infection prevention
strategy. The Joint Commission and CMS require hospitals to
have rigorous environmental cleaning policies and procedures
in place which are subject to routine audit for accreditation.
And with this new standard of care, a virtual tsunami of
products and services emerged to support these efforts.
Today, the hospital surface disinfectant market alone is
projected to be worth $1.2 billion by 2024.
Up to this point, however, infection prevention efforts
and investment aimed at reducing the risk of environmen-
tal transmission have focused almost exclusively on hard
surfaces. With the exception of isolation of patients with
serious respiratory infection, hospital air quality has received
comparatively little attention. This can be explained, in part,
by several factors: Sampling and measurement of viable
aerosolized bacteria has been both costly and burdensome.
And until recently, there has been an absence of innovation
in technology for hospital air quality management. With
limited evidence and no new solutions on the horizon, it is
understandable that other infection prevention concerns
took priority over air.
In the U.S., the importance of airborne transmission to
HAI generally is a matter of considerable debate. However,
in the case of SSI, there are many reasons why healthcare
institutions should consider air quality the next frontier
for reduction.
SSIs are complex and multifactorial, yet 30 years of studies
demonstrate the contribution of aerosolized bioburden
to SSI. As far back as the 1980s, Lidwell found that most
bacteria contaminating surgical wounds are likely to have
reached it by the airborne route. Whyte found that 98
www.healthcarehygienemagazine.com • november 2019
percent of bacteria in patients’ wounds after surgery in a
conventionally-ventilated operating room came directly or
indirectly from the air. 3-4 The recent outbreak of M. chimaera
found to be epidemiologically linked to aerosolized bacteria
from contaminated heater-cooler units used in cardiac surgery
is a more recent reinforcement of the airborne route in SSI. 5
While progress has been made in SS reduction, the Agency
for Healthcare Research and Quality (AHRQ) reported no de-
crease, between 2014 and 2017, in a core group of SSIs subject
to reporting to NHSN. 1 SCIP, SIP and other initiatives aimed
at standardization of best practice yielded improvement and
new evidence may lead to identification of additional process
improvement opportunities, however, the low-hanging fruit
in process and practice has likely been harvested.
So, where do we go from here? Rethinking air quality in the
OR may be the place to start. Sweden and the Netherlands
have promulgated standards in the last two years which
limit bacterial colony forming units (CFUs) in key areas of the
hospital based on patient risk. 6 In the OR, air quality must
be maintained at no greater than 10 CFUs per cubic meter
(<10CFU/m3). Additional European nations and Australia
are considering similar requirements, and the WHO recently
issued a conditional recommendation that laminar airflow
ventilation systems should not be used to reduce SSI risk for
patients undergoing total arthroplasty surgery. 7
Requirements for air quality management date to the
1970s and focus on the mechanism of air management
not the efficacy of those controls. This is understandable
given the absence of innovation in air quality management
technology. Since the 1970s, architectural controls have been
the only viable approach; however, there is a steady flow
of research which calls the efficacy of these controls into
question. For example, studies have demonstrated that air
exchanges and positive air pressure are easily thwarted by
door openings and traffic. 9-11
Rethinking OR air quality may be particularly important as
the population ages and demand for surgery with implants
increases. A recent study predicted exponential growth
in total hip and knee arthroplasty (THA/TKA) procedural
volume between 2020 and 2030. With no abatement in the
rate of infection, by TKA/THA prosthetic joint infections will
increase by 14 percent. 12 
For the unabridged version of this article and references, visit:
https://www.healthcarehygienemagazine.com/is-it-time-to-
rethink-air-quality-in-the-or?/(opens in a new tab)
Kathy Warye is the founder and CEO of Infection Pre-
vention Partners where she provides strategic guidance on
the commercialization of solutions that detect, prevent or
manage infection.
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