1.1 Introduction
There is a growing awareness of the impact of hospital acquired infection on resource utilisation in the NHS. Evidence is also increasing that this problem is affecting primary care services. The adequate decontamination of medical devices is one factor in their prevention.
With concern over the potential risk of person to person transmission of vCJD through the use of medical devices (iatrogenic transmission), the UK Health Departments have reiterated the importance of following published guidance on the decontamination of medical devices1.
The Scottish Executive Health Department therefore established a Working Group, led by Dr. David Old, Reader in Microbiology at the University of Dundee Medical School to advise it with regard to these questions:
1. Are current guidelines on the cleaning and sterilisation of surgical instruments adequate?
2. How effectively is that guidance being implemented?
3. What practical difficulties are there in ensuring good practice?
4. What measures need to be taken to improve the effectiveness of cleaning and sterilisation in the NHS in Scotland?
The Working Group met on four occasions. Appendix 1 provides details of its membership.
There is little collated routine data on the efficacy of decontamination in the NHS. SEHD therefore commissioned NHS Estates and the Scottish Centre for Infection and Environmental Health (SCIEH) to carry out a review of current decontamination practices in healthcare premises in Scotland. Healthcare premises are defined as NHS Trust hospitals, general medical and dental practices and private hospitals. The aims and objectives, methodology, results and conclusions of the review are presented in section 2 of this report.
The findings of the Review were presented to the Working Group. Following careful consideration, the Working Group put forward a number of recommendations which are presented in Section 3 of this report.
1.2 Background
Decontamination is the combination of processes, including cleaning, disinfection and/or sterilisation, used to render a re-useable medical device safe for further use (see Appendix 2). Historically the development and introduction of decontamination techniques and practices have underpinned the expansion of healthcare especially in hospitals.
Today decontamination is an issue of public health importance because of:
An estimated 9% of hospital in-patients have a hospital acquired infection at any one time3, the most common being urinary tract, surgical wound and lower respiratory tract infections. Common risk factors are the state of health of the patient (e.g. underlying chronic illness, concomitant infections, poor nutritional status), other therapies (especially immuno-suppression) and the type of procedure performed (especially catheterisation and "dirty" surgical operations)4.
It is estimated that between 15% and 30% of HAI can be prevented by better application of existing knowledge and realistic infection control practice5. The proportion of HAI which could be prevented by improved decontamination practice is difficult, if not impossible, to estimate. However it is well known that decontamination failures can result in a range of infections6,7. It is likely that in many sporadic cases of HAI, the fact that ineffective decontamination has been a contributing factor, will often go unrecognised. Effective decontamination can therefore make an important contribution to lowering the prevalence of HAI.
Available epidemiological evidence suggests that normal social or routine clinical contact with a patient suffering from any type of CJD (including vCJD) does not present a risk of transmission. There is no evidence of vCJD having been spread from person to person in healthcare situations. However the possibility that vCJD can be transmitted in this way arises from a number of reasons:
The Spongiform Encephalopathy Advisory Committee (SEAC) which advises UK government departments on transmissible spongiform encephalopathies, considers that the effective decontamination of instruments is a key measure in reducing the risk of TSEs. Increasing attention is therefore being paid to ensuring medical devices are effectively decontaminated before re-use and when necessary and wherever possible, employing single-use instruments for a range of procedures.
A joint SEAC/ACDP (Advisory Committee on Dangerous Pathogens) group advises government and produces guidance on infection control measures related to vCJD and other TSEs in health care settings. Their most recent guidance was published in 199815. It outlines a series of measures which are constantly reviewed in the light of new findings about these unusual diseases and the agents which cause them.
1.3 Decontamination Practice
The aim of decontamination is to make re-usable medical devices safe for use on a patient and for staff to handle without presenting an infection hazard.
The Working Group limited its considerations to the decontamination of re-usable medical devices particularly those that are invasive by intent, (e.g. surgical instruments) or are likely to be invasive inadvertently. Decontamination of sanitary appliances, general laundry processes, cleaning of crockery/cutlery etc. was not reviewed. Neither was the use of antibiotics as a decontamination measure considered.
The processes involved in decontamination are described using the model developed by NHS Estates, of the "life-cycle" of re-usable surgical instruments (see Figure 1.1). Relevant definitions are included in Appendix 2.
To undertake decontamination effectively requires all the processes illustrated in the life cycle to be implemented correctly, with appropriate controls and monitoring in place. The speed at which medical devices pass through the cycle can impact on the efficacy of decontamination. A key factor influencing this is the size of the stock of devices requiring processing. Achieving minimum standards at each stage of the life cycle depends on location; facilities available; equipment used; how the process is managed, and the policies and procedures employed. The basic requirements for good decontamination practice are summarised in Table 1.
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Table 1 Basic requirements for good decontamination practice |
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Wherever possible, decontamination processes should be automated. Systems should be in place which trace medical devices through the life cycle and can link them to the individual patients they have been used on.
In Scotland, the facilities in which the key decontamination processes of cleaning, disinfection and sterilisation take place fall into two broad, but not mutually exclusive categories:
Guidance and specific requirements relating to decontamination practice have been published over many years. The standards applied have become more stringent as a result of greater knowledge and experience. Technological advances such as microprocessor control systems have made better control economically feasible. Information about decontamination is currently available to healthcare organisations through:
A summary of principal standards and guidance is presented in Appendix 3. Guidance on the decontamination of medical devices has been collated in a CD-ROM and issued to all NHS Trusts and related organisations16.
No single agency has responsibility for ensuring compliance to standards and guidance related to the decontamination cycle. The following have a role:
The SEHD’s "Scottish Infection Manual"17 provides guidance on core standards for the control of infection in hospitals, healthcare premises and the community interface. Health Boards are responsible for ensuring that adequate standards of infection control are met by NHS organisations in their area especially by assessing the adequacy and effectiveness of infection control policies and procedures.
Since 1 April 1999, the corporate governance of all NHS bodies in Scotland has encompassed both financial and quality issues. Trust Chief Executives are accountable for ensuring care delivered within each Trust meets relevant standards.
The SEHD Manual17 recommends that all Trusts have Infection Control Committees and Infection Control Teams, which are responsible for preparing infection control policies and monitoring compliance with standards (as specified by the Health Board). It is recommended that among those policies should be one for cleaning, disinfection and sterilisation.
The guidance contained in SHTM 2010 (see Appendix 3) indicates that senior management should designate a Microbiologist (Sterilizers) who is responsible for advising the user of sterilizers on the microbiological aspects of washing, disinfection and sterilization.
Healthcare providers have responsibilities under the Health and Safety at Work etc. Act 1974 and the Control of Substances Hazardous to Health (COSHH) Regulations to ensure the health and safety of their employees and others (including visitors and patients) and to control and manage the risk of infection.