Can surgical smoke present a hazard to the general or respiratory health of operating-theatre workers? Clare Tregoning investigates.
In this case study, the environmental hazard of surgical smoke in a day-case operating theatre is explored by evaluating smoke exposure and its impact on health.
The manager of an operating theatre raised concerns with the organisation’s OH adviser about the health and safety of staff and their exposure to surgical smoke. New employees had highlighted this issue, which had not been raised previously.
A risk assessment of the electro-surgery equipment was undertaken, and prolonged exposure to unevacuated surgical smoke was identified. According to Marsh (2012), this poses a risk of ill health to those significantly exposed.
There are several documents relating to electro-surgery equipment, hazards of by-products generated and risks to those that are exposed. The Medicines and Healthcare Products Regulatory Agency (MHRA), Health and Safety Executive (HSE), Occupational Safety and Health Administration (OSHA) and the British Occupational Health Society (BOHS) acknowledge risks to health for those exposed. However, the HSE (2012) says that there is a lack of statistical ill-health data relating to surgical smoke, and MHRA (2012) says that the ill-health effects require further study, as there is no conclusive validated evidence to prove or disprove harmful effects. The HSE suggests that exposure to smoke of any kind should be avoided.
Following the risk assessment, it was noted that the surgical smoke in the theatre department had no means of evacuation. Local evacuation ventilation (LEV) enables a suction system to remove the surgical smoke plume at the point of origin before it enters the atmosphere or is inhaled by individuals in the vicinity (Hill et al, 2012). Currently, there is no legal requirement for surgical departments to install LEV systems for use during surgical procedures.
Following the identification of the hazard of surgical smoke and the risk of staff exposure, employers have a legal requirement under the Control of Substances Hazardous to Health Regulations (COSHH) to safeguard employees. Exposure to chemicals contained within surgical smoke can be controlled by implementing LEV equipment. Hill et al, (2012) and MHRA (2008) suggest that this is the single most effective method of controlling the emission of surgical smoke.
Description of the hazard
The scrub nurse’s role in the operating theatre is to assist the surgeon throughout the surgical procedure. The process involves being in close proximity to the source of surgical smoke when electro-surgery devices are used.
Surgical smoke consists of chemicals, noxious substances, viruses and destructed tissue matter, according to Mowbray et al (2013), and may contain toxic and carcinogenic constituents (MHRA, 2008). When inhaled, this can result in airway irritation and, with prolonged and repeated exposure, pulmonary conditions such as bronchitis may develop. Skin and eye irritation can also occur.
As a result of repeated or prolonged exposure, ill-health effects such as acute and chronic inflammatory respiratory changes, headache, nausea, sneezing, eye irritation, dizziness, throat irritation, anxiety, carcinoma and viruses may occur (Pierce et al, 2011).
No LEV was used together with the electro-surgery device in this case, therefore surgical smoke freely entered the surrounding atmosphere, allowing those present to inhale the smoke. The theatre in question has an air-conditioning system, which has a high rate of air filtration and replacement to remove circulating anaesthetic gasses. However, a standard theatre air-ventilation system does not prevent smoke emission into a theatre.
Face masks worn by surgeons and scrub nurses are effective in protecting against the biological hazards associated with blood and body-fluid splashes but do not provide sufficient protection for those in direct contact with surgical smoke. This is because masks are worn loosely over the face and are not sealed, allowing smoke to disperse through the gaps. These unsealed face masks are fitted, sealed breathing respirators which protect against breathable contaminants and respiratory irritants. However, there was no such equipment available in the day-case operating theatre and they are not generally used for minor surgical procedures.
Day-case operating theatre staff received no training or information regarding surgical smoke or LEV systems. This had implications for employers regarding ill health, as it could be argued that employees were not aware of the potential risk to health posed in performing their working role.
Analysing the effects
Electro-surgery equipment is used to facilitate tissue dissection and coagulation. An electric current generates heat that passes through the tissues, causing cell membranes to rupture, releasing a smoke by-product into the atmosphere as vapour, chemicals and particle matter. This, collectively, is referred to as surgical smoke, or a smoke plume.
As mentioned above, components of surgical smoke can be classed as chemical and biological agents. It is estimated that there are 150 chemical compounds found in the by-products of cell destruction, which include toxic substances such as ethane, hydrogen cyanide, carbon monoxide, benzene and acrylonitrile (Gianella, 2012).
Some of these substances may also be categorised as carcinogens (Fitzgerald et al, 2012). There are concerns that surgical smoke may be carcinogenic, due to the known carcinogenic effects of some of the chemicals present, and Hill et al (2012), postulate that the chemical groups present in surgical smoke that represent the greatest hazard are acrylonitrile, hydrogen cyanides and benzenes.
|Hazardous chemicals in surgical smoke|
The high temperature that causes tissue and cell destruction does not destroy all organisms contained within the tissue (Hill et al, 2012). Live cellular-biological components such as viruses, blood fragments and cellular elements are present in surgical smoke, which may present an infection risk due to the transmission of viable cells.
The presence of intact viral DNA from human immunodeficiency virus (HIV) and human papillomavirus cells have been identified in previous studies. The particle matter size of surgical smoke is significant, as the ill-health effects resulting from exposure to airborne particles are proportionate to their diameter. Small particles can penetrate to the deepest part of the pulmonary system, with the inflammatory respiratory changes well documented as emphysema, asthma and chronic bronchitis.
How does surgical smoke constitute a health risk?
The irritant effect of chemicals and particles contained within surgical smoke are recognised as a cause for concern. Both small and larger particles can have an irritant effect on the airway; however, smaller particles are able to penetrate the innermost areas of the lungs. The process of inhaling particles and respiratory irritants with prolonged exposure may induce acute inflammatory changes in the respiratory tract, causing pulmonary conditions such as pulmonary fibrosis, emphysema, occupational asthma and bronchitis (Brüske-Hohlfeld et al, 2008).
Measures currently in place
Historically, the function of a surgical face mask was to protect patients from infections harboured by members of the surgical team, and to protect the surgical team from body-fluid spray. However, standard surgical masks worn by theatre workers do not offer adequate protection from surgical smoke as they are not effective in capturing or filtering it.
The day-case operating theatre staff were using the standard loose-fitting surgical masks, as these were the only masks provided. And the theatre itself possessed only a designated standard ventilation system that produces air exchange rates of at least 15 exchanges per hour. According to the HPA (2012), this ventilation system is not adequate in filtering surgical smoke. Bigony (2007) says that LEV devices have been demonstrated as effective in limiting theatre workers’ exposure to the health hazard of surgical smoke.
Following an assessment that indicates the presence of surgical smoke, LEV devices should be implemented if that is the most effective way of controlling the hazard (COSHH, 2005). There is no plausible excuse for not eliminating a preventable workplace health hazard (Stocks et al, 2012).
However, it was acknowledged by the manager that there was a fundamental lack of knowledge about the potential risks to health from exposure to surgical smoke and the role LEV played in reducing that risk. Continuous professional development and increased knowledge on the risks to health from the work environment is essential in providing a safe place to work.
Therefore, it is advised that an education and orientation programme should be implemented to facilitate the health and safety of theatre staff.
A key issue is whether or not there is sufficient validated evidence to suggest surgical smoke is a hazard, and therefore whether or not this establishes a risk to exposed workers, as it is not proven or disproven whether or not surgical smoke is harmful to general or respiratory health.
It has been identified that exposure to the chemical components of surgical smoke causes ill-health effects, and that prolonged exposure to combustive particle matter may cause a variety of pulmonary conditions.
MHRA (2008) recognises that there are risks to health for staff exposed to surgical smoke. However, following a critical review of the research on the effect this hazard has on health, an investigation gap has been identified, which is highlighted by the absence of sufficient validated research on the effects surgical smoke has on those exposed to it.
There are two guidance documents released in the UK by MHRA and BOHS that acknowledge exposure to smoke of any kind should be avoided, as general exposure to gases, fumes and dusts are implicated in the development of chronic and acute respiratory conditions.
A limited number of unvalidated reports conclude that hazardous substances may be associated with surgical smoke (Hill et al, 2012). Therefore, it is advised that further research into surgical smoke should be carried out.
It should be noted that the hazard of surgical smoke is not entirely eliminated by introducing an LEV system, but it is greatly reduced. This, along with increased knowledge and training on surgical smoke, will significantly decrease the risk to employee health from hazardous contaminants.
- Modification to electro-surgery equipment is required with the addition of LEV.
- Regular maintenance of LEV and training in its use should be carried out by a competent person.
- Evaluation of advised modifications should be carried out within 12 months.
- Theatre staff should be trained on the risks to health from surgical smoke and the use of LEV.
- Those responsible for health and safety in operating theatres should be aware of any new research concerning surgical smoke.
Clare Tregoning is an occupational health adviser at Morriston Hospital in Swansea.
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