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Infection control team in the operating room: separating aspiration from reality!
Journal of Hospital Infection (1999) 42: 265–267
LEADER
Infection control team in the operating room: separating aspiration from reality! H. Humphreys Professor of Clinical Microbiology and Consultant Microbiologist,The Royal College of Surgeons in Ireland and Beaumont Hospital 123, St Stephen’s Green, Dublin 2, Ireland The risk of infection following surgical procedures is determined by a number of factors including the underlying health of the patient, the type of procedure (e.g., whether occurring in a clean or contaminated area of the body), the expertise of the surgeon and the environment. Most postoperative infection is caused by organisms that are part of the endogenous flora, such as urinary infection caused by perirectal bacteria following genitourinary surgery. Whilst measure may be taken to minimize this such as the use of sterile instruments and perioperative prophylactic antibiotics, many other factors such as the skill of the surgeon are beyond the control of the infection control team (ICT). The contribution that the inanimate environment in the operating theatre makes to postoperative infection is probably over stated.1 Nonetheless, input from ICTs on environmental aspects of the operating theatre and in the writing and implementation of theatre protocols is often requested, but infection control doctors and infection control nurses are often confused about their role in this area and how it can best be discharged. Operating theatre design and lay-out has been the subject of a number of official reports but these are usually very technical in nature and somewhat intimidating for most ICT members. A recent historical review of operating theatre design has highlighted changing perspectives such as the move away from separate ‘clean ‘ and ‘dirty’ corridors, and emphasizes that attempts to control infection have 0195–6701/99/080265 + 03 $12.00
been based on common sense and general principles, in the absence of scientific data.2 It is therefore more important for the ICT to understand the general principles of operating theatre design and to try and ensure that these are incorporated in to new or refurbished theatres, rather than spending a lot of time attempting to fully understand technical detail. The ICT can also reinforce good practice by visiting the operating theatre area and ensuring the best use of facilities and resources. For example cost savings can be achieved by ensuring that theatre clothing or ‘scrubs’ are worn by operative staff in whom the reduction in airborne bacteria from the perineum, thighs and feet is likely to be of most significance in contributing to minimizing post-operative infection.3 In contrast, the use of such clothing by non-operative staff, e.g., theatre secretaries, is unlikely to help reduce postoperative infection. Indeed, the sight of non-operative staff wearing masks hanging around the neck is one that we have all seen and despaired of! Similarly, ultraclean facilities such as are present in many orthopaedic theatres are often used inappropriately. The impact of ultraclean ventilation, which supplies air with very low bacterial air counts, is likely to be countered by not preparing instruments in the ultraclean area, or by not covering them before use.4 Where such relatively sophisticated and expensive facilities are available, other infection prevention measures such as minimizing the numbers of personnel in the operative area are often forgotten because © 1999 The Hospital Infection Society
266
of an implicit assumption that there is an additional margin of comfort or safety by the provision of air with very low particle and bacterial counts. The provision of ventilated facilities in operating theatres was given momentum in the late 1940s following the launch of the National Health Service and the publication of a number of official reports.1,2 With the increasing use of minimally invasive or laparascopic surgery, we are beginning to see the use of non-ventilated facilities for some procedures. Most of the nonventilated theatres in a recent survey conducted in Great Britain and Ireland were 20 or more years old and the procedures undertaken included hernia repairs, cystoscopies, tonsillectomies and the removal of lumps.5 This may well have changed since the survey because of the rapid pace of changes taking place in surgical practice. As hospital trusts are forced to contain costs and minimize hospital stay, it is likely that hospital executives, surgeons and others will consider carrying out more procedures in non-ventilated rooms because of increasing pressure on already busy facilities, or because of the absence of the capital resources required to construct new operating theatre facilities. The importance of monitoring bacterial air counts in operating theatres remains a subject of some debate and there is also some confusion as to how this should be done and when is the best time to do it. Air sampling is recommended as part of theatre commissioning6 and is recommended as routine practice in ultraclean facilities.6,7 Questions arise as to whether sampling in an empty theatre is of much use as surgical operations take place in an environment where the personnel present contribute significantly to air bacterial counts. Furthermore, methodologies vary from the use of settle plates to the use of one or more Casella slit samplers or equivalent, and it is not clear how many samples should be taken and from where. A recent study by Friberg and co-workers correlated air and surface counts in two differently ventilated theatres and the results suggest that surface sampling, i.e., settle plates, may have a
H. Humphreys
role because they reflect the bacterial load nearest the operative site,8 and the subsequent study by the same group reported in the current issue (pp 287–293), draws further attention to the difficulties in defining standards. Indeed, sampling close to the surgical wound with a sterilizable extension tube, as suggested by Gosden and colleagues9 may be the most appropriate way to sample but practical issues arise such as ensuring that particle loss is minimal and controlling for factors that may influence bacterial counts such as the type of surgical procedure taking place, the number of scrubbed personnel, and the movement in and out of the theatre. In response to a number of recent publications in this Journal and considerable debate by members of the Hospital Infection Society (HIS) E-mail discussion group, it is opportune to consider many of these issues in order to provide ICTs with clear guidance and sensible evidence-based recommendations. Consequently, the HIS has established a multidisciplinary Working Party to assess the scientific data underpinning many current recommendations and to provide ICTs with clear and understandable advice regarding theatre design and the provision of minimum facilities for the conduct of surgery. It is also hoped that the Working Party will be able to provide realistic advice and guidance on bacterial air sampling and theatre clothing. There will be an extensive consultation exercise as part of the Working Party’s deliberations and drafts will be circulated on the HIS website. Finally, advice and suggestions on which aspects require particular attention, and even encouragement will always be welcome!
References 1. Ayliffe GAJ. Role of the environment of the operating suite in surgical wound infection. Rev Infect Dis 1991; 13 (Suppl 10): S800–4. 2. Essex-Lopresti M. Operating theatre design. Lancet 1999; 353: 1007–10. 3. Belkin NL. Use of scrubs and related apparel in health care facilities. Am J Infect Control 1997; 25: 401–4.
Infection control team in the operating room: separating aspiration from reality!
4. Chosky SA, Modha D, Taylor GJS. Optimisation of ultra-clean air. The role of instrument preparation. . J Bone Joint Surg (Br) 1996; 78-B: 835–7. 5. Humphreys H, Stacey AR, Taylor EW. Survey of operating theatres in Great Britain and Ireland. J Hosp Infect 1995; 30: 245–252. 6. Holton J, Ridgway GL. Commissioning operating theatres. J Hosp Infect 1993; 23: 153–160. 7. Whyte W, Lidwell OM, Lowbury EJL, Blowers R. Suggested bacteriological standards for air in ultraclean operating rooms. J Hosp Infect 1982; 3: 123–135.
267
8. Friberg B, Friberg S, Burman LG. Correlation between surface and air counts of particles carrying aerobic bacteria in operating rooms with turbulent ventilation: an experimental study. J Hosp Infect 1999: 42: 61–8. 9. Gosden PE, MacGowan AP, Bannister GC. Importance of air quality and related factors in the prevention of infection in orthopaedic implant surgery. J Hosp Infect 1998; 39: 173–180.
LEADER
Infection control team in the operating room: separating aspiration from reality! H. Humphreys Professor of Clinical Microbiology and Consultant Microbiologist,The Royal College of Surgeons in Ireland and Beaumont Hospital 123, St Stephen’s Green, Dublin 2, Ireland The risk of infection following surgical procedures is determined by a number of factors including the underlying health of the patient, the type of procedure (e.g., whether occurring in a clean or contaminated area of the body), the expertise of the surgeon and the environment. Most postoperative infection is caused by organisms that are part of the endogenous flora, such as urinary infection caused by perirectal bacteria following genitourinary surgery. Whilst measure may be taken to minimize this such as the use of sterile instruments and perioperative prophylactic antibiotics, many other factors such as the skill of the surgeon are beyond the control of the infection control team (ICT). The contribution that the inanimate environment in the operating theatre makes to postoperative infection is probably over stated.1 Nonetheless, input from ICTs on environmental aspects of the operating theatre and in the writing and implementation of theatre protocols is often requested, but infection control doctors and infection control nurses are often confused about their role in this area and how it can best be discharged. Operating theatre design and lay-out has been the subject of a number of official reports but these are usually very technical in nature and somewhat intimidating for most ICT members. A recent historical review of operating theatre design has highlighted changing perspectives such as the move away from separate ‘clean ‘ and ‘dirty’ corridors, and emphasizes that attempts to control infection have 0195–6701/99/080265 + 03 $12.00
been based on common sense and general principles, in the absence of scientific data.2 It is therefore more important for the ICT to understand the general principles of operating theatre design and to try and ensure that these are incorporated in to new or refurbished theatres, rather than spending a lot of time attempting to fully understand technical detail. The ICT can also reinforce good practice by visiting the operating theatre area and ensuring the best use of facilities and resources. For example cost savings can be achieved by ensuring that theatre clothing or ‘scrubs’ are worn by operative staff in whom the reduction in airborne bacteria from the perineum, thighs and feet is likely to be of most significance in contributing to minimizing post-operative infection.3 In contrast, the use of such clothing by non-operative staff, e.g., theatre secretaries, is unlikely to help reduce postoperative infection. Indeed, the sight of non-operative staff wearing masks hanging around the neck is one that we have all seen and despaired of! Similarly, ultraclean facilities such as are present in many orthopaedic theatres are often used inappropriately. The impact of ultraclean ventilation, which supplies air with very low bacterial air counts, is likely to be countered by not preparing instruments in the ultraclean area, or by not covering them before use.4 Where such relatively sophisticated and expensive facilities are available, other infection prevention measures such as minimizing the numbers of personnel in the operative area are often forgotten because © 1999 The Hospital Infection Society
266
of an implicit assumption that there is an additional margin of comfort or safety by the provision of air with very low particle and bacterial counts. The provision of ventilated facilities in operating theatres was given momentum in the late 1940s following the launch of the National Health Service and the publication of a number of official reports.1,2 With the increasing use of minimally invasive or laparascopic surgery, we are beginning to see the use of non-ventilated facilities for some procedures. Most of the nonventilated theatres in a recent survey conducted in Great Britain and Ireland were 20 or more years old and the procedures undertaken included hernia repairs, cystoscopies, tonsillectomies and the removal of lumps.5 This may well have changed since the survey because of the rapid pace of changes taking place in surgical practice. As hospital trusts are forced to contain costs and minimize hospital stay, it is likely that hospital executives, surgeons and others will consider carrying out more procedures in non-ventilated rooms because of increasing pressure on already busy facilities, or because of the absence of the capital resources required to construct new operating theatre facilities. The importance of monitoring bacterial air counts in operating theatres remains a subject of some debate and there is also some confusion as to how this should be done and when is the best time to do it. Air sampling is recommended as part of theatre commissioning6 and is recommended as routine practice in ultraclean facilities.6,7 Questions arise as to whether sampling in an empty theatre is of much use as surgical operations take place in an environment where the personnel present contribute significantly to air bacterial counts. Furthermore, methodologies vary from the use of settle plates to the use of one or more Casella slit samplers or equivalent, and it is not clear how many samples should be taken and from where. A recent study by Friberg and co-workers correlated air and surface counts in two differently ventilated theatres and the results suggest that surface sampling, i.e., settle plates, may have a
H. Humphreys
role because they reflect the bacterial load nearest the operative site,8 and the subsequent study by the same group reported in the current issue (pp 287–293), draws further attention to the difficulties in defining standards. Indeed, sampling close to the surgical wound with a sterilizable extension tube, as suggested by Gosden and colleagues9 may be the most appropriate way to sample but practical issues arise such as ensuring that particle loss is minimal and controlling for factors that may influence bacterial counts such as the type of surgical procedure taking place, the number of scrubbed personnel, and the movement in and out of the theatre. In response to a number of recent publications in this Journal and considerable debate by members of the Hospital Infection Society (HIS) E-mail discussion group, it is opportune to consider many of these issues in order to provide ICTs with clear guidance and sensible evidence-based recommendations. Consequently, the HIS has established a multidisciplinary Working Party to assess the scientific data underpinning many current recommendations and to provide ICTs with clear and understandable advice regarding theatre design and the provision of minimum facilities for the conduct of surgery. It is also hoped that the Working Party will be able to provide realistic advice and guidance on bacterial air sampling and theatre clothing. There will be an extensive consultation exercise as part of the Working Party’s deliberations and drafts will be circulated on the HIS website. Finally, advice and suggestions on which aspects require particular attention, and even encouragement will always be welcome!
References 1. Ayliffe GAJ. Role of the environment of the operating suite in surgical wound infection. Rev Infect Dis 1991; 13 (Suppl 10): S800–4. 2. Essex-Lopresti M. Operating theatre design. Lancet 1999; 353: 1007–10. 3. Belkin NL. Use of scrubs and related apparel in health care facilities. Am J Infect Control 1997; 25: 401–4.
Infection control team in the operating room: separating aspiration from reality!
4. Chosky SA, Modha D, Taylor GJS. Optimisation of ultra-clean air. The role of instrument preparation. . J Bone Joint Surg (Br) 1996; 78-B: 835–7. 5. Humphreys H, Stacey AR, Taylor EW. Survey of operating theatres in Great Britain and Ireland. J Hosp Infect 1995; 30: 245–252. 6. Holton J, Ridgway GL. Commissioning operating theatres. J Hosp Infect 1993; 23: 153–160. 7. Whyte W, Lidwell OM, Lowbury EJL, Blowers R. Suggested bacteriological standards for air in ultraclean operating rooms. J Hosp Infect 1982; 3: 123–135.
267
8. Friberg B, Friberg S, Burman LG. Correlation between surface and air counts of particles carrying aerobic bacteria in operating rooms with turbulent ventilation: an experimental study. J Hosp Infect 1999: 42: 61–8. 9. Gosden PE, MacGowan AP, Bannister GC. Importance of air quality and related factors in the prevention of infection in orthopaedic implant surgery. J Hosp Infect 1998; 39: 173–180.