Introduction

Decontamination is a process that eliminates or reduces the level of microbes and other unwanted material from reusable medical devices, equipment and surfaces, which may otherwise transfer to a susceptible site and cause infection or colonisation. The purpose is to make these items safe for reuse on patients and for staff handling. We can achieve decontamination through a combination of cleaning, disinfecting and sterilising. The procedures detailed here are those required to eliminate or reduce microbial contamination. Additional precautions may be required to eliminate sources of chemical or radioactive contamination from equipment. Always refer to your local policy.

Risk assessment

Staff must decontaminate all reusable medical devices following each episode of use. To determine the appropriate method of decontamination, it is necessary to carry out a risk assessment for every medical device that you use. Broadly, we can divide equipment into three categories (high-, medium- and low-risk), according to the risk of infection associated with using a piece of equipment. You can determine the appropriate category (and the level of decontamination required) for each medical device according to the degree of contact that the equipment will have with the patient and the likely contact with blood or body fluids. However, the exact method of decontamination you select must also take account of the contamination present; the tolerance of the item to heat, pressure, moisture and chemicals; the processing equipment available; and the risks associated with the chosen method. For example, for high-risk items, cleaning followed by heat sterilisation is generally preferred. However, you may have to use chemical disinfection for heat sensitive items.

Only reprocess reusable medical devices. Never reprocess medical devices designated for single-use only.

High-risk items

High-risk items include all reusable medical devices that you use in close contact with a break in the patient’s skin or mucous membranes, and devices that enter a sterile body area of the patient. For reusable high-risk items, the appropriate means of decontamination is cleaning followed by sterilisation. All high-risk items must be sterile at the point of use. Examples of high-risk items include surgical instruments, laparoscopes, syringes, needles and catheters.

Medium-risk items

Medium-risk items are medical devices used in contact with mucous membranes, items contaminated with particularly virulent or readily transmissible organisms, and items that you intend to use on an immunocompromised patient. For reusable medium-risk items, the appropriate means of decontamination is cleaning followed by disinfection (or sterilisation). However, cleaning alone may be acceptable in some agreed situations. Examples of medium-risk items include respiratory equipment, gastrointestinal endoscopes and thermometers.

Low-risk items

Low-risk items are medical devices used in contact with a patient’s healthy intact skin, and equipment that does not have close contact with the patient. For these items, cleaning is sufficient. However, disinfection may be necessary if there is a known infection risk. Examples of low-risk items include tourniquets, washing bowls, bedding, baths, furniture, toilet seats, floors, walls and sinks.

Single-use items

Single Use Instruments: The Facts
educational resource supplied by Rocialle InHealth

If an item is marked for single-use, it means that you must only use it on a single occasion and then discard it²¹. You should never use a single-use device on multiple occasions on a single patient or on different patients. You will be personally liable if you cause any damage or injury by reusing an item marked for single-use only²².

If a medical device is marked for single patient use, you can use the item for multiple uses on one patient and then you must discard it. Examples of single patient use devices include plastic syringes for insulin injection, suction tubing, urethral catheters and vaginal cones. Some form of reprocessing may be necessary between uses on the same patient. Always make sure you follow the manufacturer’s instructions.

Before using a prepacked sterile single-use or single patient use medical device, check that the packaging is intact and the product is within its use-by date (refer to Symbols link below). Such devices must be stored in a clean area off the floor. You should rotate the stock to ensure that you use older stock before it reaches its expiry date.

Wherever possible, you should use single-use devices, provided they do not compromise the clinical outcome.

Symbols

The symbols used on medical devices and their packaging are detailed in Appendix 3 Device Bulletin MDA DB2000(04).

Decontamination of endoscopes

All staff who are involved in processing endoscopes should follow the advice and guidance set out in Device Bulletin 2002(05) and Medical Device Alert 2004/028^26,27. The Medical Devices Agency provides further information²⁸.

Decontamination of endoscopes is complex and must only be undertaken by staff who are trained to decontaminate the particular endoscope and accessories in question. There are many different types of endoscope, each supplied with various accessories (e.g. valves, water bottles, guide wires, injector sheaths).

No endoscope should be put into use without a validated reprocessing procedure being in place, and staff must take great care to follow this local procedure accurately. The local reprocessing procedure must be in accordance with the advice provided by the Medical Devices Agency and the manufacturer.

This resource is unable to provide details of the correct decontamination procedure for every type of endoscope available within the healthcare environment. However, the following information may be useful.

Generally, endoscopes that enter a normally sterile body cavity are high-risk devices and therefore must be sterilised prior to use. Those that contact intact mucous membranes but do not invade sterile body cavities are medium-risk and may be decontaminated using high-level disinfection. However, the infection risk associated with a particular endoscope also depends on the clinical condition of the patient, nature of the procedure and the type and contamination status of the endoscope used. The exact method of decontamination selected will also depend on the physical nature of the particular endoscope and the tolerance of the various materials to the different decontamination methods available.

Endoscopes can be categorised as either rigid or flexible. Rigid endoscopes are usually used for invasive procedures and flexible endoscopes for non-invasive procedures. However, flexible versions of invasive endoscopes are also available. Flexible endoscopes and gastrointestinal endoscopes are generally more complex and create more difficulties in decontamination. Where autoclavable scopes are available they should be purchased in preference to those that cannot be processed in this manner. Currently it is rigid scopes that can normally be autoclaved in SSD and flexible scopes that are reprocessed through an Endoscopy Unit. Scopes should be high-level disinfected at the start of the day before procedures begin, between patients and at the end of the day. Scopes should be stored in designated storage cupboards so that they do not come into contact with other scopes and are not recontaminated. If damage is detected at any stage the scope must be withdrawn from service and the manufacturer consulted.

Where practicable, you should use single-use accessories. If unavailable, reusable accessories should be compatible with steam sterilisation. The Medical Devices Agency recommends that a Sterile Services Department carries out all reprocessing of rigid endoscopes and reusable accessories.

You should begin decontamination as soon as possible after use of the endoscope. Thorough cleaning with a suitable detergent and warm water according to the manufacturer’s instructions is essential. Where possible, you should always use an automated cleaning process, rather than manual cleaning. If manual cleaning is undertaken, staff must wear appropriate personal protective clothing including aprons, gloves and facial protection. The endoscope should be dismantled and cleaned carefully with brushes, paying particular attention to the lumens and occluded surfaces, and then thoroughly rinsed. Use of an ultrasonic cleaner and an enzyme detergent solution is recommended where the manufacturer specifies that this is acceptable. The scope should be leak tested and inspected for damage before being placed in an automated endoscope reprocessor.

After cleaning, the endoscope must be decontaminated by either high-level disinfection or sterilisation. Using an automated cleaning process is the preferred method. High-risk endoscopes (i.e. those used for invasive procedures) such as arthroscopes, laparoscopes and cystoscopes, should ideally be sterilised using either steam or gas plasma. Where this is not possible, e.g. for heat sensitive rigid endoscopes and flexible endoscopes, you should consider using a high-level chemical disinfectant. For medium-risk endoscopes (i.e. those that touch intact mucous membranes but do not invade a sterile body cavity), you can use high-level disinfection using liquid disinfectant immersion.

Outbreaks

During outbreaks of infection, the Infection Control Team may require increased cleaning frequencies or the use of more stringent decontamination processes. You should seek advice from your local Infection Control Team if you have any concerns.

Outbreaks of infection associated with inadequately decontaminated equipment must be thoroughly investigated. If a problem is identified with a decontamination process that could raise concern for public health or causes concern about controlling infections, you must inform the local consultant in communicable disease control.