VOL: 101, ISSUE: 08, PAGE NO: 52
Shila Patel, RGN, BSc, Dip(Infection control), is clinical nurse specialist, infection control, Epsom and St. Helier University Hospitals NHS TrustBed frames and mattresses as a source of risk
Bed frames and mattresses as a source of risk
Bed frames and mattresses may become contaminated by skin scales that are covered with microscopic organisms such as Staphylococcus aureus (O'Connor, 2000), body fluids, including urine and faeces, and organisms transmitted via unwashed hands. All of these have been associated with outbreaks of infection.
Loomes (1988) found that an antibiotic-resistant strain of acinetobacter was responsible for colonising and infecting patients in the burns and intensive care units despite the implementation of strict isolation precautions. During the investigation of the outbreak it was observed that one patient's mattress cover was badly stained and that the mattress inside was wet. Further investigation revealed that there were 23 mattresses with stained covers that were no longer impervious to fluids. Bacteria were isolated from inside 15 of these mattresses, nine of which were the same resistant strain of acinetobacter.
In a more recent study, Catalano et al (1999) found that an epidemic strain of Acinetobacter baumannii was isolated from a bed rail during an outbreak in an intensive care unit that had lasted for four months. The study concluded that, while the bed rail did not by itself explain the transmission of the organism, it did illustrate that dry vectors can serve as secondary reservoirs for the survival of bacteria such as Acinetobacter baumannii.
Methods of decontamination
There are three levels of decontamination: cleaning, disinfection and sterilisation. Selection of an appropriate decontamination method should be determined by the level of risk posed by a piece of equipment (Table 1). Manufacturers' instructions on equipment decontamination should also be consulted.
Beds and mattresses are classified as low risk, therefore the level of decontamination required is cleaning, which physically removes organic soiling and micro-organisms (Medical Devices Agency, 1996). If undertaken correctly it removes approximately 80 per cent of micro-organisms (Ayliffe et al, 1967). Subsequent drying removes residual moisture and reduces the potential for microbial growth.
Selecting a cleaning agent
Bed frames and mattresses may be cleaned using hot water and detergent, followed by thorough drying (Ayliffe et al, 2000). Detergent-impregnated surface wipes are also available, but as little appears to have been written about these it is difficult to comment on their efficacy.
Where disinfection is required, for instance if there is obvious blood contamination, a chlorine-releasing solution should be used and the bed thoroughly rinsed with fresh water to minimise the corrosive effects of the chlorine solution (Department of Health, 1991). It is important that the chlorine-releasing solution has 10,000 parts per million available chlorine in order to inactivate the blood-borne viruses (Ayliffe et al, 1993).
Use of other products, such as clear soluble phenolics, should be avoided as they may render mattress covers permeable to fluids (Ayliffe et al, 2000). Similarly, alcohol-based products, such as 70 per cent industrial methylated spirit, are unsuitable for mattress cleaning because of the potential for de-lamination of the mattress cover.
Static foam mattress covers and bed frames - Hands should be decontaminated before and after the cleaning procedure to minimise any cross-contamination risks. Disposable plastic aprons should be worn to prevent contamination of uniforms. Routine use of gloves is unnecessary, unless the bed frame or mattress is visibly contaminated with blood or body fluids.
A fresh solution of hot water and detergent should be prepared in a clean bowl. The bed frame and mattress cover may then be cleaned using disposable paper towels or a disposable cloth. Ensure that all surfaces of the bed frame and mattress are cleaned. The detergent solution should then be discarded, the bowl washed and fresh water used for rinsing the bed frame and mattress. Both should be dried thoroughly. If there is contamination with blood, a chlorine-releasing solution (10,000 part per million available chlorine) should also be used. Finally, wash the mattress and bed frame with hot water and detergent (excess blood may be soaked up with paper towels first, if necessary).
Specialist pressure-relieving mattress systems - Many manufacturers of pressure-relieving mattress systems now offer total bed management services, including decontamination of the bed frame and mattress. However, if such a service is not available, the manufacturer's instructions should be followed, taking care to disconnect the electric supply before carrying out the procedure.
Frequency of cleaning
There is a lack of consensus about how often beds should be cleaned. According to Ayliffe et al (2000), bed frames do not require routine cleaning following patient discharge unless they are visibly soiled, but the authors do suggest that these should be included in regular cleaning schedules. Wilson (2001) agrees that bed frames should be included in regular cleaning regimes. In contrast, O'Connor (2000) advocates that bed frames should be decontaminated between each patient use or once a week if they have been used by a single patient.
From the evidence quoted in this article it would seem reasonable to suggest that bed frames and mattresses should be cleaned between each patient use in order to minimise any cross-infection risks. Where a single patient uses a bed for extended periods of time, the literature suggests that the bed frame and mattress must be cleaned if visibly soiled and that regular weekly cleaning would be a good standard to achieve.
Testing for mattress cover impermeability on static foam mattresses
A visual inspection of the mattress and mattress cover should be undertaken regularly - weekly would be ideal, or according to local policy. The covers should be checked to detect any signs of wear, rips, staining or loss of impermeability (Wilson, 2001). Both sides of the mattress and mattress cover must be inspected. Any irregularities should be recorded and reported according to local policy.
In addition to visual inspection of the mattress, a simple water test for impermeability should be carried out on an annual basis unless a problem is suspected. This is done as follows:
- Remove bed linen and unzip the mattress cover;
- Visually inspect both sides of the inner foam for any evidence of moisture or staining, which indicates loss of impermeability;
- Place disposable paper towels on the inner foam underneath the mattress cover (around the centre of the mattress where the buttocks would lie);
- Pour a small quantity of water (20-30ml) on top of the mattress cover and press firmly;
- Leave for approximately 30 seconds;
- Remove and inspect the disposable paper towels;
- Any evidence of wetness on the disposable paper towels indicates that the mattress cover is not impervious to fluids;
- Re-zip the mattress cover;
- Dry the wet area of the bed;
- Remake the bed with bed linen unless the mattress needs to be replaced.
The results of such testing must be accurately and appropriately documented and reported. If the water test fails and there is visible staining on the mattress itself, the mattress must be replaced to minimise the risks of cross-infection. However, if the water test fails and there is no visible staining the mattress cover should be changed.
Bed frames and mattresses have been implicated in outbreaks of infection, particularly in high-risk areas involving vulnerable patients. It is important that both bed frames and mattresses are regularly cleaned using hot water and detergent or detergent-impregnated wipes, and inspected for damage. Mattresses and mattress covers should also be visually inspected on a regular basis and a water test for impermeability undertaken.