10 minute read
Building a culture of safety and health at work
Hiro Tanaka
Hiro Tanaka is the Editor of JTO and a Council member of the BOA. He co-directs the BOA Future Leaders Programme.
Everyone has the right to life, to work… to just and favourable conditions of work… Everyone has the right to a standard of living adequate for the health and well-being of themselves and of their family.
- Universal Declaration of Human Rights, UN, 1948
The Annual World Day for Health and Safety at Work on the 28th of April promotes the prevention of occupational accidents and diseases globally. It is an awareness-raising campaign, intended to focus attention on the magnitude of the problem, and on how creating a safety and health culture can reduce the number of work-related deaths and injuries. This responsibility lies with each one of us. From government, NHS employers, surgeons in the workplace and our profession. As surgeons, we strive to provide the highest quality of care to our patients. In doing so, we expose ourselves to hazards that have the potential to compromise not only our health, but our ability to deliver the best care throughout our career. The aim of this series of articles is to increase awareness of the guidelines and preventative measures to create the safest possible work environment.
What are the hazards?
Most orthopaedic surgeons are aware of the occupational hazards specific to the specialty, which include radiation exposure, infectious organisms, chemical hazards, surgical smoke, noise pollution, musculoskeletal injury and psychological stress [1,2]. It is easy to acknowledge them as “part of the job that we do”, rather than to consider the long-term effects that they may have. The consequences of repetitive exposure over many years are additive and simple preventative measures can prolong careers. We must also be aware of emerging technologies such as robotic surgery, new biomaterials and nanotechnology, which may pose unidentified risks in the workplace.
The exposure and risk from hazards are not uniform across our profession. They may vary according to subspecialty (eg, arthroplasty and cement fumes), gender (radiation exposure), racial background (BAME COVID-19 risk), habitus (musculoskeletal injury) and pre-existing disabilities. It is, therefore, essential that safety and health at work is improved within the framework of equity and diversity of our workforce.
Hierarchy of controls
Imagine that a hazardous substance splashes into the eye of a chemical plant operator while taking a sample. The worker is not seriously injured, and the subsequent investigation focuses upon training, personal protective equipment and the circumstances of the event. But did anyone ever ask whether the worker needed to take the sample at all?
The National Institute for Occupational Safety and Health (NIOSH) [3] defines five rungs of hazard mitigation, which start with controls that are the most effective to the least effective.
Elimination – physically removes the hazard.
Substitution – replace the hazard.
Engineering controls – isolate people from the hazard.
Administrative controls – change the way people work.
Personal protective equipment (PPE) –protect the worker.
PPE is the least effective control and yet it is the area that gains the most attention in healthcare. Jonathan Back from NIOSH said, “You can’t eliminate every hazard, but the closer you can get to the top, the closer you can reach that ideal and make people healthier and safer.”
In light of the previous article by Hannah Sevenoaks et al., this series will start by exploring the principles of radiation safety.
Exposure to radiation
Orthopaedic surgeons have a greater exposure to ionising radiation compared to other specialists, because the use of intra-operative imaging is an essential part of modern trauma and orthopaedic surgery. Despite this, there is no mandatory requirement for surgeons in the UK to undertake formal radiation and protection training. The radiation in orthopaedics study by Raza et al identified that 92% of UK surgeons used intra-operative X-rays at least once per week and yet 38% had received no formal safety training [4].
There is no safe dose of radiation. Radiation damage occurs at a cellular level. The direct damage may result in breaking of molecular bonds, resulting in cell death or distorted replication, which is believed to be the initial step in radiation-induced carcinogenesis or indirectly through the generation of free radicals.
What is the UK legislation and governance?
Ionising radiation poses a risk to not only the surgeon, but the patient, nursing staff, radiographers and the anaesthetic team. Their safety is covered by the Ionising Radiation Regulations 2017 (IRR17) [5] and the Ionising Radiation (Medical Exposure) Regulations 2017 (IR(ME)R17), which are enforced by the Health and Safety Executive (HSE). IRR17 deals with exposure to employees and the public, and IR(ME)R17 to patients.
Radiation exposure should comply with a concept known as ALARA which means “as low as reasonably achievable”. It is synonymous with ALARP (practicable). The optimisation principle requires consideration of its use at all, its application during surgery, engineering and design to reduce exposure, and adequate PPE.
Hospitals appoint Radiation Protection Supervisors (RPSs) to ensure local compliance with regulations and undergo training courses, with refresher courses every 3-5 years.
All workplace-related deaths, accidents and occupational diseases including cancer must be reported by the employer to the HSE via Reporting of Injuries, Diseases and Dangerous Occurrences (RIDDOR)
What is the statutory occupational exposure limit?
The occupational dose limits are set by the International Commission on Radiological Protection (ICRP) and defined by IRR17. The effective dose is the tissue-weighted sum of all the equivalent doses in all body organs and represents the probability of cancer induction. Some body tissues have a higher sensitivity to radiation relative to body mass and, therefore, are given a higher weighting. For example ICRP103(2017) has a weighting of 0.12 for breast, 0.08 for gonads, 0.04 for thyroid and 0.01 for skin.
The maximum effective dose limit in IRR17 is:
• 20 mSv per year
• Or 100 mSv in any consecutive five years with a maximum of 50 mSv in any single year.
Once a pregnancy is confirmed and the employer notified, the employer must ensure that the equivalent dose to the foetus will unlikely exceed 1 mSv for the remainder of the pregnancy.
There are separate equivalent dose limits for the eye and thyroid.
To put things into perspective, we are all exposed to background radiation in our everyday lives and most people are exposed to 3 mSv of radiation per year. A chest X-ray exposes a patient to 0.1 mSv, a CT of the abdomen is 10 mSv.
What is the risk to my health?
Increased rates of malignancies in orthopaedic surgeons compared to the normal population have been reported [6], as well as higher prevalence of breast cancer among female surgeons [7]. In addition, there is a significantly higher risk of complications during pregnancy [8] and even congenital abnormalities among the offspring of surgeons [9].
It is important to be mindful that these self-reported studies do not attribute causation to radiation exposure, but it does highlight the need to take safety at work seriously.
What should I do with the C-arm?
Most of the radiation exposure from a C-arm comes from scattered radiation, which is significantly less than the primary beam. Therefore, awareness of good fluoroscopy practices can dramatically reduce radiation exposure over time. The exposure rate from the primary beam from a standard C-arm can be as high as 12-40 mSv per minute, while the scatter is about 0.05 mSv at 2 feet and 0.01 mSv at 4 feet.
There are four recommended methods of reduce radiation exposure from scatter:
Positioning / contamination control
Increasing distance
Shielding
Decrease time.
Positioning tips
Radiation levels are highest where the beam enters the surgical site, therefore it is important to be aware of the design of the C-arm. The radiation beam is emitted from the “Hammerhead” and the intensifier (receiver) is flat (Figure 1).
Vertical positioning. When vertically orientated, the optimal position to minimise scatter would be to position the radiation tube/emitter under the patient and the image intensifier above the patient. This would decrease the scatter delivered to your upper body and eyes.
Lateral positioning. Where possible, avoid the use of a horizontally orientated C-arm, for example, in hip or spine surgery. Standing on the emitter side can result in a four to eightfold increase in radiation exposure [10]. Instead, consider the 70-degree oblique view.
Oblique positioning. Stand on the side of the patient (on the side of the intensifier) and tilt the intensifier towards you. Tilting the intensifier towards your legs reduces exposure to your upper body and neck.
Distance. During orthopaedic trauma procedures, your hands are most vulnerable to exposure. Spinal surgeons are particularly at risk of hand exposure during insertion of pedicle screws. Stepping away just 1 foot from the beam can reduce scatter radiation by 300 times [11] and 2 meters by 4,000 times.
Collimation. Most C-arms are designed to use collimation, which serves to narrow the beam of radiation and control scatter (Figure 2).
Laser guide. This allows centering of the beam and avoids unnecessary inadequate images.
Shielding
With shielding, 0.25mm lead gowns will attenuate 90% of the radiation, whereas 0.5mm will attenuate 99% at the cost of added weight and potential problems with musculoskeletal strain. Many units provide 0.35mm gowns as a balance of benefits.
For surgeons with pre-existing musculoskeletal problems, modern lead-free gowns are available, which are 30% lighter. The limitations of standard gown design in the protection of breast tissue have been highlighted in this issue.
Thyroid shields of 0.5mm thickness achieve 90% of exposure reduction, as well as leaded glasses which provide better protection than ordinary glasses.
A single dosimeter under a protective gown is not sufficient to measure the radiation doses to other parts of the anatomy such as the eyes, hands and neck. Better practice would be to use one above and one below the apron for surgeons at risk.
Is a Mini C-arm better?
The Mini C-arm has gained popularity among hand and foot/ankle surgeons because they have 1/10th of the radiation scatter of a standard C-arm. However, the same radiation protection principles should be applied in its use. There is a danger that the ultimate radiation absorption may be higher for a Mini C-arm due to increased fluoroscopy time, and decreased distance between the surgeon and the emitter. In one study, its use resulted in a 10-fold increase in the output and double the absorption to the surgeon’s hand [12]. Therefore, while it is theoretically safer, it may not necessarily be a better alternative in practical use.
Key learning points
Always consider the radiation principles of positioning, distance, shielding and time.
Ensure correct orientation of the C-arm. Emitter at the bottom.
Be aware of scatter when radiation is deflected from the patient or surfaces.
Step away from the beam when screening, if able to do so.
Avoid the use of the C-arm in the true lateral position where possible.
If a lateral view is required, consider a 70-degree view, with the beam directed away from the operating surgeon.
Consider the additional value of each image to the success of the procedure and minimise the overall number of images.
Avoid live screening.
Wear appropriate, correctly fitting PPE.
References
References can be found online at www.boa.ac.uk/publications/JTO.
