|
NATIONAL SPECIFICATION FOR ALTERNATING
PRESSURE MATTRESS OVERLAYS
NHS Purchasing and Supply Agency
Over the life of the EPUAP to date, there has often been debate regarding
the need for formal specifications of pressure redistributing beds, mattresses
and cushions. Within the UK the National Health Service Purchasing and
Supply Agency recently released such a draft specification covering alternating
pressure mattress overlays. This draft specification is printed in full
in this issue of the EPUAP by kind permission of the NHS Purchasing and
Supply Agency. We hope that the publication of this specification will
generate debate among EPUAP members - are there other specifications currently
in development (or indeed been finalised!) within other countries? If
other specifications exist, we would be delighted to reprint them in the
EPUAP Review to allow members to see the current state of play of specification
development across Europe. Members may wish to consider whether we as
a European organisation should be seeking to work with public bodies to
develop such specifications? Please send any specific comments upon the
UK draft specification direct to Nikki Aylward <nikki.aylward@doh.gsi.gov.uk>.
SPECIFICATION FOR ALTERNATING PRESSURE AIR MATTRESS
OVERLAY FOR ADULTS
1. Construction
a) Mattress overlay
- Constructed in one layer of either replaceable cells
individually attached to manifold or of two or more sheets welded together,
whichever more economical overall. 16-19 cells, all alternating. All
connections to be secured (e.g., glued over barbed connector or clipped
over groove, not push-fit) to resist pull force of 25kg.
- Construction will allow profiling, without any loss
of function.
- Fully enclosed within waterproof cover zipped at least
on two short and one long sides. Zip protected with skirt. Cover will
not hammock between alternating cells.
- Dimensions inflated: length and width to comply with
specifications for hospital bed dimensions as specified by National
and International regulations when supplied for hospital use; otherwise
a range of sizes suitable for domestic use should be provided; depth
13-15cm.
- Rapid deflation for CPR by disconnection of air tubes
from the mattress at the normal point of attachment deflation for the
thorax should be achieved within 15 seconds for an individual of 70kg
and normal BMI.
- Attached to underlying mattress by head and foot end
flaps which are secured in place by continuous elasticised bands miming
from the long edges of the mattress under the underlying mattress.
- Maximum weight not to exceed 15kg
b) Connecting tubes
- Tubing of a durable, kink resistant material (e.g.,
EPDM rubber), at least 60cm and not more than 100cm long.
- Attached to motor with high quality positive mechanical
latch connectors (e.g., plastic Colder connector at least 1.9cm external
diameter or equivalent). Plastic to plastic or metal to metal but not
mixture. Connectors on the pump unit to be attached and secured (e.g.,
glued over barbed connector, clipped over groove or screwed in, not
push-fit) to resist pull force of 25kg. Attached to pump unit with adequate
separation between connectors to allow easy connection and disconnection
of mattress.
- Tubing permanently attached to mattress and secured
(e.g., glued over barbed connector or clipped over groove, not push-fit)
to resist pull force of 25kg.
c) Pump unit
- Dimensions: not more than 13cm deep, 33cm wide. Height
should not impede use of bed stripper when pump unit is suspended from
foot board of bed.
- Box constructed of impact resistant, smooth, easily
decontaminated material. Recessed control panel to protect from accidental
damage. Rounded internal corners to facilitate cleaning.
- Attachment to foot end of bed by hook built into box
top (see figure 2). Alternative option of placing on the floor in an
upright position.
- Controls:
on/off switch back lit to show when power is
on,
override for 'power off alarm.
- Alarms audible and visual. Different lights for each
alarm preferred:
power off,
'patient grounding (mattress not supporting
patient above base)',
Automatic reset of alarms in event of power
failure or power surge.
- Electrical connection: wire at least 510cm long, permanently
attached to motor, with live ends insulated with plastic jackets (which
insulate the wire ends if pulled out of the motor casing).
- Maximum noise output not to exceed 40 dB (A) when
measured 100cm from pump unit. (viii) Maximum weight not to exceed 8kg.
2. Performance
- Mode of action
The overlay will operate by cyclically changing the air pressure in
individual cells from a minimum between 0-5 mmHg and a maximum between
80-120 mmHg. The time for individual cells to complete one inflation
and deflation cycle should be 8-15 minutes.
- Lifting capacity
The overlay will lift a 100kg patient of normal BMI at least 2 cm above
an underlying solid surface and maintain function.
- Mechanical reliability
Not more than one breakdown caused by manufacturing/design faults per
year per mattress is permitted in the first year of usage (excludes
user error/accidental damage).
- Transport mode
Activated by disconnection from power supply. Overlay will continue
to alternate or pressure will be equalised between the two cell sets
and be maintained. In transport mode, the overlay will lift a 100kg
patient of normal BMI at least 2 cm above an underlying solid surface
for at least 4 hours.
3. Instructions
- Essential installation, user, cleaning and safety
instructions printed on mattress cover and pump unit. Manufacturer contact
number on mattress and pump unit.
- Detailed maintenance manual available on request.
- CPR instruction to be attached to connecting tubes
and pump unit so that they are visible when bed made up.
4. Warranties
- The product will comply with Medical Devices Directive
93/42/EEC June 14 1993 and any subsequent amendments.
- Product will be manufactured for at least 5 years
in identical external form unless mandated for or required to by an
adverse incident report. Spare parts will be available for at least
5 years after termination of product manufacture.
5. Additional items, which must be available on request
- Carrying bags (not zip fastened).
- Spare parts available individually from a part's list.
- Extension tube set of 2-3m.
6. Additional features
The above specification is for a baseline model. Before
agreeing to any additional features the purchaser should consider whether
they are necessary and whether any additional cost is justified by the
benefits. They should also be aware that additional features may in
some circumstances render the alternating overlay less clinically effective,
less mechanically reliable or more prone to misuse and/or mismanagement.
Additional features not included in specification -
Listed for discussion
1a) Construction of mattress
(i) Mattress to have non-alternating head set
Potential benefits:
more comfortable for patients nursed without pillow.
Potential disadvantages:
increased risk of pressure ulcers on the head and also
on heels if mattress accidentally used head to foot reversed.
(ii) Specify vapour permeable, two way stretch cover
Potential benefits:
thought to increase patient comfort.
Potential disadvantages:
no clinical evidence of benefit or improved comfort.
(iii) Construct mattress in a fashion which allows
the mattress to be its own 'carrying case' when rolled up (i.e., provide
straps etc., to hold it rolled together, plus carrying handles) so that
a need for carrying cases is eliminated.
Potential benefits:
no need for separate carrying cases which are frequently
lost in some areas. Reduced costs.
Potential disadvantages:
not required in many areas - additional expense.
Infection control issues if soiled mattresses are carried
around without being first placed in another container.
(iv) Provide ventilation holes in mattress
Potential benefits:
improves patient comfort by increasing air at the patient/mattress
interface.
Potential disadvantages:
requires battery back-up for transport mode.
(v) Bottom of mattress clearly printed with message
"Turn mattress over. It must be used other side up".
Potential benefits:
reduced chance of incorrect positioning of mattress
Potential disadvantages:
increased cost
2a) Mode of action
Maximum operating pressure pertinent to a given, set either by the
user or by internal mechanisms (i.e. have either a manually set or automatically
adjusted 'comfort control').
Potential benefits:
Mattress can be made softer and therefore more comfortable for some lighter
patients.
Potential disadvantages:
In practice, rarely set correctly if manual. Thus usually no benefit for
lighter patients but risk of pressure sores for heavier patients as they
can bottom through mattress. Automatic systems expensive to date. More
potential for mechanical failure with both systems, more complicated maintenance.
2b) Lifting capacity
Maximum lifting capacity of 150kg.
Potential benefits:
Can carry heavier patients. Average patient mass is increasing year on
year.
Potential disadvantages:
Inflation pressures would need to be higher, increasing discomfort problems
for lighter patients. Shorter working life for mattress and pump unit.
Alternative solutions:
Nurse patients >150 kg in weight on mattress replacement systems
|
