Joan Gray, RGN.
Director of Clinical Education at Sterilox Technologies International, Beaconside, Stafford, StaffordshireOccupational asthma is the UK's most frequently reported occupational respiratory disease: it is extremely debilitating for sufferers and distressing for their friends and family. With around 1500 to 3000 new cases each year, the condition has been estimated to cost society up to £1.1 billion over 10 years. This figure rises to 7000 cases per annum if asthma that is exacerbated by work (work-related asthma) is included (HSE, 2004a).
Occupational asthma is the UK's most frequently reported occupational respiratory disease: it is extremely debilitating for sufferers and distressing for their friends and family. With around 1500 to 3000 new cases each year, the condition has been estimated to cost society up to £1.1 billion over 10 years. This figure rises to 7000 cases per annum if asthma that is exacerbated by work (work-related asthma) is included (HSE, 2004a).
Glutaraldehyde is known to be one of the main causes of occupational asthma (HSE, 2004b) and, although independent data does not exist, the chemical is thought to still be used within the health-care sector by up to 15% of UK hospitals as their first-choice endoscope disinfectant.
Glutaraldehyde is a powerful biocide that was first introduced in 1963 (Hanson et al, 1990). Until relatively recently it has been the only widely available disinfectant for the reprocessing of flexible endoscopes and other heat-sensitive equipment, although routine exposure is now known to cause anything from mild skin or eye irritation to full-scale occupational asthma (HSE, 1998). Glutaraldehyde also has commercial applications outside of health care that are linked either to its biocidal or fixative properties (see Box 1).
To minimise occupational exposure and protect at-risk staff, the UK's Health and Safety Executive has introduced increasingly stringent handling precautions for glutaraldehyde (HSE, 1998). Despite this, some staff are unknowingly and accidentally being exposed to dangerously high levels of fumes in their day-to-day work in endoscopy units and theatres.
Using glutaraldehyde at Essex Rivers
The Elmstead day unit at Essex Rivers Healthcare NHS Trust was opened in 1993 and carries out over 16 000 surgical procedures each year. Approximately half of that number involves flexible scopes. The trust had been using glutaraldehyde as its scope disinfectant and were following best practice guidelines for safe handling of the solution.
However, some staff risked becoming sensitised to the fumes, resulting in respiratory problems; others complained of headaches, lethargy or skin discoloration after coming into contact with the solution (OSHA, 2003).
The trust arranged for air sampling in the endoscopy room. The results revealed that during re-filling operations or ventilation breakdown fume levels of 0.2ppm (parts per million) were being recorded: above the UK's maximum exposure limit (MEL) of 0.05ppm as stated in EH40 (HSE, 2001). With these results the trust started a review of its endoscope cleaning processes.
The trust formed a committee to represent all interested parties and comprising: four gastroenterologists, the directorate manager, the day services manager, the endoscopy room supervisor, the trust's microbiologist, the local safety representative and the risk manager. The committee considered two options:
- Option A. To improve the local exhaust ventilation in the endoscopy room to a standard capable of ensuring that the MEL was not exceeded at any time
- Option B. To modify disinfection processes and replace glutaraldehyde with a safer disinfectant.
Option A had to be discounted when the engineering consultants stated that they could not guarantee fume levels staying below the MEL of 0.05ppm in the event of a ventilation breakdown.
With several safer and commercially available alternatives to glutaraldehyde (see Box 2), the trust invited five disinfectant manufacturers to present their proposals before the committee. Four companies were promoting chemical substances containing peracetic acid, while the fifth used an oxidised saline solution (a mixture of mild oxidants with hypochlorous acid as the main active species). The committee considered and scored each company on all aspects from effectiveness as a disinfectant to installation costs, from wear and tear on equipment to health and safety concerns (see Box 3 for selection criteria (Holt, 2004).
The oxidised saline solution system (Sterilox) scored highly in most areas. On the plus side the substance provided 'high-level' disinfection, was fast acting and provided bacteria-free rinse water, while having no health and safety or environmental risks. However, the system required high initial capital outlay, so was expensive to install, and at the time the lacquer coating on the trust's range of endoscopes was not fully compatible with the saline solution. Sterilox now supplies a weekly wipe system to protect the lacquer from damage and all major endoscope manufacturers offer full service contracts, guarantees and loan instruments for users.
To overcome this hurdle the committee invited several endoscope suppliers to test their equipment with Sterilox. One company supplying 'Fujinon' equipment provided the necessary guarantees. After much discussion the committee advised the trust's board that the health and safety concerns should be the priority and that Sterilox was the preferred option.
The board accepted the committee's advice even though the recommended option was the most expensive and in 2000 the system was installed. The Fujinon equipment replaced the older endoscopes initially, but by 2003 the unit used only endoscopes that were compatible with the Sterilox system.
Benefits in eliminating glutaraldehyde
The trust's replacement for glutaraldehyde achieved a high level of disinfection in just five minutes' contact time. The trust's microbiologist monitored the effectiveness of the cleaning and endorsed the substance. A high level of disinfection is good for patients and the trust believes that the risk of cross-infection between patients has been reduced to an absolute minimum.
Staff working in the endoscopy room used to complain regularly about headaches and lethargy. There have been no ill health reports since the installation of the system, nor has the issue been raised at subsequent internal health-and-safety committee meetings.
The cost of the new Fujinon endoscopes was significantly cheaper than the type being used before Sterilox was introduced. As a result the trust was able to more quickly replace the non-compatible equipment with the Fujinon range.
The trust has removed a potentially harmful substance that was a health risk to staff and replaced it with a non-toxic substance that has no health, safety or environmental risks.
Of the five substitute disinfectants examined, only Sterilox satisfied the trust's rigorous microbiological, toxicological and scope compatibility criteria.
Occupational health problems in endoscopy have been eradicated, endoscopes are turned around faster and the risk of cross-infection between patients has been reduced to a minimum.
The evaluation process the trust went through also helped to identify a new manufacturer of endoscopes which has had a significant cost benefit to the trust.
In addition, in November 2003, the trust received a good practice award from the European Agency for Safety and Health at Work.
What appeared at first to be an expensive option does not always turn out to be, as the disinfectant chosen to replace glutaraldehyde had overall cost benefits for the hospital. The trust believes success came from its early investment in two critical activities:
- Consultation and getting the right expertise
- Establishing a working group of all those concerned with patient safety and occupational health
The final solution needed to meet differing concerns but resulted in benefits for all.
The author wishes to thank Nigel Holt and his team at Essex Rivers Healthcare NHS Trust, Jean-Francois Rey of Institut Arnault Tzanck and Ulrike Beilenhoff, ESGENA, for their help in preparing this paper.
Author contact details
Joan Gray, Sterilox Technologies International. Email: email@example.com
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