Surgical smokes in
the operating theatre
Using best evidence for
health risk assessment
Marc Rhainds, M.D., M.Sc., FRCPC
Mélanie Hamel, Ph.D
Martin Coulombe, D.A.A., M.Sc., MAP
Cochrane Canada 9th
Annual Symposium
February 2011
CHUQ
Centre hospitalier universitaire de Québec






CHUQ: Leader in research and technology assessment
3 hospitals
1,063 beds
535,887 users
8,880 staff; 1,051 physicians
Annual budget: > 625M$
UETMIS
http://www.chuq.qc.ca
(implemented in 2006)
Health Technology Assessment Unit
2
Health Technology Assessment (HTA)
 Introducing new technologies can be challenging
for healthcare decision makers
 Maximize health benefits
 Risks minimization
 Cost-effectiveness
 Evidence-based information is required
 HTA is helpful to support decisions at the hospital
level
3
Objectives
 To assess the health risks associated with surgical smokes
exposure
Using this example :
 To discuss how to manage uncertainty in the evidence-based
decision making
4
Background
 It is suggested that surgical smokes produced during surgical procedures may be
harmful for healthcare professionals
 Advertising: Surgical smoke = health hazard for the staff
 Healthcare professionals in the CHUQ want to have portable smoke evacuators devices
 But is there a real risk ?
5
Risk Assessment
Objective
To assess health risks
associated with
occupational exposure
to surgical smokes
 Biological risks
 Malignant cells
 Bacteria
 Virus
 Chemical risks
 Volatile organic compounds
 Carbon monoxide
 Particulate matters
 Nuisance phenomena
 Surgical smoke: odour, obstructed
vision, eye and throat irritation
 Device: Noise
6
Methods
 Systematic reviews
 Randomized controlled trials
 Experimental studies
Until June 2010
 Pubmed
 Cochrane Library
 Grey literature
Inclusion criteria
 Various surgeries
 All electrocautery devices
Limits
 Human & animal
 English and French
 Article selection, quality assessment, data extraction
and synthesis  One reviewer
 Appraisal  Three reviewers
 Synthesis review  Expert groups
7
Results
 One systematic review was found (Burrows, 2000)
 Centre for Clinical Effectiveness (CCE), Australia
 Request: Is smoke plume from laser / electric surgical procedures a health hazard?
 Based on two expert consensus
 Author’s conclusion: “A critical appraisal of the evidence for this question was not
therefore undertaken.” (level IV evidence)
 No RCT assessing health risks associated with surgical smoke exposure was found.
 There is no data available regarding asthma, respiratory symptoms prevalence in
surgical staff exposed to surgical smokes
8
 Should we stop at this point?
 How do we help healthcare decision makers?
9
Biological Risks
Study types
Presence in
surgical smokes
Viability
Risk of
transmission
Malignant cells
Experimental
Found
Unclear
Unclear
Bacteria
Experimental
Found
Rare event
Unclear
Virus
Experimental
Descriptive
Case reports
Found
Unclear
Unclear
 Results from experimental studies show that surgical smoke may contain malignant cells,
bacteria and virus
 However, viability of cells in the surgical smokes and the potential of communicable
diseases to healthcare professionals remain unclear
10
Chemical Risks
 Data from experimental / environmental studies were compared to occupational
health and safety standards
Volatile organic compounds (VOCs) and carbon monoxide (CO)
ACGIH : American Conference of Governmental Industrial Hygienists
IRRST : Institut de recherche Robert-Sauvé en santé et en sécurité du travail
NIOSH : National Institute for Occupational Safety and Health
WHO : World health organization
OSHA : Occupational Safety and Health Administration
Particulate matters (PM)
WHO : World health organization
US EPA : US Environmental Protection Agency
11
Volatile organic compounds (VOCs),
carbon monoxide (CO) and particulate matters (PM)
Detection range
Standards range
(TWA)
Benzene
0 – 1 ppm
0.1 – 1 ppm
Toluene
0.009 – 17 ppm
50 – 200 ppm
0 – 12 ppm
100 ppm
0 - 0.0035 ppm
100 ppm
0 - 30 ppm
25 – 30 ppm
Ethylbenzene
Xylene
Carbon monoxide
Particulate matters
(PM10)
Max 21 g /
m3
Study types
Tissues
Surgical tools
Experimental
Human
Electrosurgery
(various)
Ultrasound
Environmental
Laser
exposure
Porcine
25 - 65 g / m3
(average for 24h)
TWA: Time weighted average
 Data from surgical smokes analysis, measured in the breathing zone and the operating
room, suggest that ambient air concentrations of CO, VOCs, and PM are very low and far
below the occupational exposure limits (TWA, 8 hours / day, 5 days/ week).
12
Nuisance phenomena
According to NIOSH:
Various symptoms are reported by surgical staff after
exposure to surgical smokes:
 Headache, eyes, nose and throat irritations, obstructed vision, unpleasant odours
 Noise pollution caused by the suction of smoke outlets
 We did not find any evaluation of the nuisance phenomena
13
Organization recommendations
Although there is no clear evidence that surgical smoke may represent health hazard,
many governmental organizations and professional health associations have
recommended:
 Individual protection measures
 Smoke evacuation in the operating theatre
 Use of portable evacuation and filtration systems:




To decrease the concentration of airborne pathogens in a room;
When the HVAC system cannot meet building ventilation rate requirements;
For applications which require higher flows;
When the type of pathogen and transmission mode is not yet known.
14
Risk management considerations
General ventilation in operating rooms systems (HVAC)
 Usually sufficient to remove fumes (COSSH, England)
Smoke filtration effectiveness
Limited ability for some particles (aerosols, particles of large size)
Limited effectiveness for high-capacity filters (HEPA filter)
Reduced distance between the suction nozzle and the source could
increase the efficiency
15
In the context of the CHUQ
 Perceived health risks > real risks
 Effectiveness of HVAC systems in operating rooms is not uniform between the three
hospitals
 Beyond the biological and chemical risks: should health decision making be driven by
the nuisance phenomena (odor, irritation)related to surgical smoke?
 Disadvantages associated with the use of portable smoke evactuators
 Noise
 Interference in the communication between members of the surgical team
 Size of smoke evacuators in limited space
 Device maintenance: staff formation and costs
16
Discussion

When there is no systematic review and no RCT available, what should local
HTA units do to support decision making?


Doing nothing appears not an option!
In this example of the assessment of health risks associated with surgical
smokes exposure,
1) we looked at data associated with a weak level of evidence:



Experimental studies (e.g. environmental sampling and analysis)
Expert consensus and judgment
Occupational standards (chemical exposure limits)
2) we had face-to-face meetings with strategic committees of managers and clinicians
to discuss the data available and enhance knowledge translation
17
Discussion
 Use of other data than RCT to answer questions of efficacy and
effectiveness, are we lowering the bar?
 Are we overweighting local evidence just because it is local?
 Are we overweighting our own evidence because we paid for it?
 Opportunities for field evaluation
18
Conclusions
 In this example, adapting of HTA processes was helpful to support the
decision making with the best available evidence.
 CHUQ decisions :



Positive reception from decision makers

Publication of a report : March 2011
No systematic use of portable system is expected in the CHUQ
Use of portable evacuation and filtration system restricted to specific type of
surgeries (e.g. breast)
19
Thank you !