Cochrane Canada 9th Annual Symposium February 2011 Marc Rhainds, M.D., M.Sc., FRCPC Mélanie Hamel, Ph.D Martin Coulombe, D.A.A., M.Sc., MAP Using best evidence for health risk assessment Surgical smokes in the operating theatre

2 CHUQ Centre hospitalier universitaire de Québec UETMIS (implemented in 2006) Health Technology Assessment Unit  CHUQ: Leader in research and technology assessment  3 hospitals  1,063 beds  535,887 users  8,880 staff; 1,051 physicians  Annual budget: > 625M$

3 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

4 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

5 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 ?

6  Biological risks  Malignant cells  Bacteria  Virus Risk Assessment  Chemical risks  Volatile organic compounds  Carbon monoxide  Particulate matters  Nuisance phenomena  Surgical smoke: odour, obstructed vision, eye and throat irritation  Device: Noise Objective To assess health risks associated with occupational exposure to surgical smokes

7  Systematic reviews  Randomized controlled trials  Experimental studies Methods  Pubmed  Cochrane Library  Grey literature  Article selection, quality assessment, data extraction and synthesis  One reviewer  Appraisal  Three reviewers  Synthesis review  Expert groups Until June 2010 Limits  Human & animal  English and French Inclusion criteria  Various surgeries  All electrocautery devices

8 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

9  Should we stop at this point?  How do we help healthcare decision makers?

10  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 Biological Risks Study types Presence in surgical smokes Viability Risk of transmission Malignant cells ExperimentalFoundUnclear Bacteria ExperimentalFoundRare eventUnclear Virus Experimental Descriptive Case reports FoundUnclear

11 Chemical Risks  Data from experimental / environmental studies were compared to occupational health and safety standards Volatile organic compounds (VOCs) and carbon monoxide (CO) Particulate matters (PM)  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  WHO : World health organization  US EPA : US Environmental Protection Agency

12 Volatile organic compounds (VOCs), carbon monoxide (CO) and particulate matters (PM) Detection range Standards range (TWA) Study typesTissuesSurgical tools Benzene 0 – 1 ppm0.1 – 1 ppm Experimental Environmental exposure Human (various) Porcine Electrosurgery Ultrasound Laser Toluene – 17 ppm50 – 200 ppm Ethylbenzene 0 – 12 ppm100 ppm Xylene ppm100 ppm Carbon monoxide ppm25 – 30 ppm Particulate matters (PM 10 ) Max 21  g / m  g / m 3 (average for 24h)  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). TWA : Time weighted average

13 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 Nuisance phenomena

14 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. Organization recommendations

15 Risk management considerations 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 General ventilation in operating rooms systems (HVAC)  Usually sufficient to remove fumes (COSSH, England)

16 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

17 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

18 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

19 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  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)  Publication of a report : March 2011

Thank you !