| This section will offer a basic understanding
of pressure ulcer development and how Airform can assist in
prevention and healing of pressure ulcers.
Pressure ulcers are an ancient problem and have been
identified in the remains of a mummified Egyptian priestess
(Burton, 1995). The responsibility for the formation of ulcers
has been traditionally placed on nurses' shoulders and the
expression 'bad nursing' (Norton et al, 1975., Dealey, 1992)
is a term that has been applied to any ward with pressure
ulcer incidence. This view risked leaving nurses with a sense
of guilt leading to a potential of denial or in danger of
minimising the problem (Warner, 1986). Today, pressure ulcers
present new challenges of prevention and understanding the
processes involved in the formation of a pressure ulcer can
lead to a lowered incidence.
Q: What is a
pressure ulcer?
A: A pressure ulcer is defined as a
"lesion caused by unrelieved pressure that results in damage
to underlying tissue" (US Department of Health and Human
Services, 1992) and the formation of an ulcer is a complex
mixture of intrinsic and extrinsic variables. Therefore,
immobility is the true cause of pressure ulcers but other
factors (figure 1)
contribute to the speed or intensity of damage that is caused
through the immobility.
Figure 1
| Contributory Factors |
Explanation |
| Friction |
Abrasion of the skin when rubbed against sheets or
chairs |
| Shear forces |
The skeleton is forced down by gravity whilst the
tissues remain held by sheets or seating. This movement
'pinches' the capillaries within the tissues, causing
ischaemic changes and finally death of the obstructed
tissues. |
| Analgesia Narcotics |
Reduces the natural movements found with normal
sleep patterns. The lowered movement increases risk of
tissue damage. |
| Malnutrition |
Leads to deficient tissue repair and increases
risk |
| Incontinence |
Macerates the tissues, softening them and increasing
risk of friction and shear. |
| Surgery |
Inadequate pressure relief on theatre tables or long
hours spent in one position during surgery increase the
risk if tissue damage. |
| Epidural |
Reduces natural movement and prevents identification
of pain over bony prominences. |
| Poor tissue perfusion (low O2 tension) |
COAD = high carbon dioxide levels and poor
O2 exchange.
Heart disease = low delivery
of O2 to the tissues.
Anaemia = low
O2 carrying capacity in the blood.
Low
mobility = slows the passage of blood and/or prevents O2
from reaching the tissues through pressure on bony
prominences. |
Aetiology
Pressure sores develop over bony
prominences and are due to a 'squeezing' and distortion of
tissues (pressure or shearing forces) between bone and the bed
or chair surface. Both shearing force and pressure occlude
capillaries that supply O2 and nutrients to the tissues. This
occlusion leads to ischaemia within the tissues and (if the
pressure remains unrelieved) leads finally to necrosis of the
tissue - a pressure ulcer.
There are two forms of loading, - pressure and shear
(Bliss, 1993) with pressure being the force applied vertically
to a surface and shear the force that is applied tangentially
or in parallel (Bliss, 1993). An imaginary line being drawn
through the body can demonstrate vertical force and offer a
reason for why pressure exerted on the lower part of the body
depends greatly on the position of the body. The seated
position would exert higher pressures because of the mass,
starting from the head and pressing through the length of the
body onto the small area of ischael tuberosities or sacrum. A
prone body would have less mass pressing onto a larger area
and will be less likely to develop a pressure ulcer. Shear
cannot exist unless pressure is present. Therefore, although
the prime cause of pressure ulcers is immobility, both
pressure and shear should be considered together as the
combination of the two is very damaging (Bliss,1993).
Q: How often should patients be
'turned'?
A: The traditional method of pressure
ulcer prevention has relied on 'two hourly turns' where nurses
proceeded from immobile patient to immobile patient, turning
them onto their alternate side every two hours. This method of
prevention relied on custom rather than clinically based
evidence, although repositioning the patient regularly did
offer some reduction in pressure ulcer incidence.
Nevertheless, acutely ill patients may require turning hourly
or even more often and a rationale for turning patients should
be considered for the following reasons;
- Staffing levels can mean turning regimes cannot always
be adhered to.
- Patients in pain may wish to remain still and unmoving
for as long as possible to reduce painful episodes.
- Medically unstable patients may require to be left
longer in one position, thereby increasing the potential of
pressure sore development.
- Repositioning patients can increase the risk of shearing
and friction, even when hoists are used.
- Hussian (1953) found that sustained pressure of 100mmHg
over 2 hours caused irreversible changes in the muscles of
rats; if this relates to humans then 2 hours without change
of position is too long. This is particularly relevant when
the findings of Swain (Medical Devices Agency, 1993)
demonstrated that pressures between a patient and the
standard hospital contract mattress can be as high as
150mmHg.
- Lifting patients can strain nurses' backs, therefore,
manual handling must be kept to a minimum.
There is
therefore, an argument against 'regular' repositioning of
patients as repositioning too often may cause discomfort and
pain. Nevertheless, patients should never be left in one
position too long without;
- An appropriate support surface for the condition of the
patient.
- Repositioning for comfort, toileting, or eating - at
least four hourly - as remaining in one position for longer
than four hours can also be uncomfortable and may lead to
increased risk of chest infection or DVT.
Assessment
A risk assessment tool,
(Waterlow 1988) can be applied in an holistic assessment of
pressure ulcer risk. Skillful assessment means that prevention
can become a reactive process rather than a proactive one -
still reliant on assessment but reacting to an obvious
deterioration in the patient's pressure areas rather
identifying the potential for tissue damage and preventing
that damage in a proactive way. Proactive care would be
through use of appropriate equipment and through addressing
the negative factors that increase risk (figure 1).
There is, however, an effective compliment to the risk
assessment tool - that of physical assessment whenever the
patient is moved. Any blanching redness found through physical
assessment (figure 2)
will identify a developing pressure ulcer and indicates that
the patient is either on an inappropriate mattress or is not
being repositioned often enough. This redness must lead to
urgent change in care - a higher-grade mattress or increased
repositioning times must be introduced. This is an extremely
important, even vital, part of assessment and can totally
prevent pressure ulcers forming in previously pressure ulcer
free patients.
Figure 2
| Grade |
Type |
Description |
| 1 |
Blanching hyperaemia |
Reddened area over a bony prominence. Skin redness
present but turns white when a finger is pressed into
the centre. |
| 2 |
Unblanching hyperaemia |
Discoloration of the skin that does not change
colour when pressed. |
| 3 |
Blister, scrazed or broken skin |
Break in the skin involves dermis only |
| 4 |
Cavity wound |
Ulcer extends beneath dermis into subcutaneous
fat |
| 5 |
Cavity wound involving bone |
Infective necrosis | (Torrance
1983)
Q: Can all pressure ulcers be
prevented?
A: Pressure ulcers can be prevented if
the accumulating damage (indicated by blanching hyperaemia) is
noted early enough. Patients who fall or collapse at home and
remain on the floor for some time before discovery, will be
developing a pressure ulcer before hospital admission. As the
breakdown of tissues do not occur immediately but can take
some days, a subsequent pressure ulcer may be blamed onto
'poor nursing' even though the damage had occurred prior to
admission. This may be one reason why orthopaedic units have a
higher incidence than other wards with incidence possibly as
high as 42.7% (Department of Health, 1993). These ulcers may
not be prevented although assessment and use of appropriate
equipment can arrest further damage.
Patients who are nursed on appropriate equipment at night,
but who sit in chairs for long periods are likely to develop
pressure ulcers, particularly if the chair does not have
pressure relieving properties to match the mattress. These
ulcers are preventable!
Q: How can pressure ulcers be
prevented?
A: Prevention relies on three elements:
- Excellent risk assessment.
- Proactive care (relieving pressure and addressing
factors that influence pressure ulcer development).
- Continued physical assessment.
Sareo Healthcare
Ltd manufacture two mattresses that offer a total package of
care in the prevention of pressure ulcers. A static system,
Pressurease, which is designed to assist in the prevention of
pressure ulcers, and a unique dynamic system, Airform, which
is designed for use with patients who are very high risk or
who have established pressure ulcers.
Duration of pressure is a known element of pressure ulcer
development and prevention is simple - regularly relieve the
pressure in the 'at risk' areas such as bony prominences.
Airform is a unique dynamic air system that alters the
patient's pressure points every 6 minutes. This will prevent
pressure damage from occurring and will increase healing in
established pressure ulcers. The patient in picture 1 and 2,
had a large undermined pressure ulcer, nursed with the ulcer
on the mattress, which healed in 6 weeks of Airform therapy.
This patient is part of a large Airform evaluation project,
which is demonstrating the Airform effectiveness in healing
established pressure ulcers.
Shearing forces are reduced by use of the Airform mattress
as the air cells are encased in a shell of Intellifoam
visco-elastic foam. This dampens the motion of the air-cell
alternation, and as such reduces discomfort and does not
therefore transport the patient along the bed during the
air-cycle change thereby reducing shear. The Airform mattress
fully conforms to the body shape and the foam 'moulds' around
the body. This conformability removes the hot-spots of
pressure from the bony prominence and redistributes pressure
to a larger surface area. Patients who experience discomfort
when nursed on a conventional dynamic air mattress, will
identify an essential difference when placed onto an Airform
mattress.
Other Methods of Prevention
The 30-degree
tilt (Preston 1988) is an excellent method of
repositioning patients without lifting and with minimum
disturbance to the patient; it also reduces the potential for
friction damage. The 30-degree tilt (appendix 1) can also be
effectively used on the Airform mattress, when repositioning
patients.
Suggested Plan of Care
- Complete a risk assessment using an established
assessment tool such as the Waterlow system (Waterlow 1988).
- History of previous collapse/fall? - provide Airform
mattress.
- Waterlow risk of up to 25 - provide Pressurease
mattress.
- Waterlow risk of over 25 - provide Airform mattress.
- Established pressure ulcer - provide Airform mattress.
- Surgical procedure lasting >3 hrs - provide Airform
mattress.
- Complete a physical assessment at least 2 times daily.
Blanching erythema present? Use higher-grade mattress and/or
increase repositioning times.
- Review nutritional status and offer supplements when
necessary.
- Ensure the chair has an appropriate pressure
reducing/relieving cushion to match the mattress.
Conclusion
There is only one cause of
pressure sores and that is unrelieved pressure linked to the
many causative factors. Knowledge of these factors and of how
to address the problems they present, along with an
understanding of the physiological response of the tissue to
sustained pressure, will enable practitioners to make informed
decisions in prevention of pressure sores.
Airform and Pressurease mattresses, linked with excellent
physical patient assessment, provides a solution to the
problem of pressure ulcer formation and an answer to the
problem of healing established pressure ulcers.
References
Bliss, M. (1993) Aetiology of pressure
sores. Reviews in Clinical Gerontology. 3. 379-397.
Burton, P. (1995) Prevention is better than cure. Journal
of Community Nursing. July. 18-20.
Dealey, C. (1992) Pressure sores: The result of bad
nursing? British Journal of Nursing. Editorial. 1. 15. 748.
Department of Health. Pressure Sores a Key Quality
Indicator. (1993) HMSO London.
Husian, T. (1953) An Experimental Study of some Pressure
Effects on Tissues with Reference to the Bed-Sore Problem.
Journal of Pathology and Bacteriology. 66. 347-358.
Norton, D., McLaren, R., Exton-Smith, A. (1975) An
investigation of geriatric nursing problems in hospital.
Churchill Livingstone. London.
Preston, KW. (1988) Positioning for comfort and pressure
relief; the 30o degree alternative. Care: Science and
Practice. 6. 4. 116-119
Warner, U. (1986) Pressure sores: a policy for prevention.
Nursing Times. Occasional Paper. April. 59-61.
Waterlow, J. The Waterlow Card for the Prevention and
Management of Pressure Sores: Towards a Pocket Policy. Care
Science & Practice. (1988) 6. 1
30o Tilt Method
- For this manoeuvre, 2 extra pillows are required:
- As with all procedures, the patient should be informed.
- Two nurses are required (A & B) 1 on each side of
the bed.
- Raise the bed to waist level.
- Ask the patient to turn their head in the direction they
will be turned. Ask them to cross their arms across the
chest.
- Nurse A will have 2 pillows prepared.
- Nurse A will untuck the long bottom sheet and pass the
edge over the patient to nurse B.
- Nurse B folds or rolls the edge of the sheet to form a
hand-hold. The rolled edge of the sheet will be halfway
across the patient.
- Nurse B grips the sheet in line with the patient's
shoulder and hip.
- With arms straight, nurse B rocks back onto one foot,
using the body weight to roll the patient. (Picture 44) The
patient will be at an angle of approximately 40o and will be
comfortably cocooned in the sheet. Nurse B will be in a
non-stressful position.
- Nurse places a pillow from the patient's shoulder (with
the pillow end under the top pillows) to waist.
- The patient is relaxed back onto the pillow and the
sheet is arranged over the top.
- The patient is now at an angle of 30o and the head
pillows can be arranged for comfort.
- Nurse A will lift the leg on to a second pillow which is
placed lengthways. The long edge of the pillow should be
between the patient's legs to ensure that knees and ankles
do not connect and cause pressure.
- A third pillow, placed lengthways, can be used to
support the other leg if required.
The weight of the
patient is an important factor, particularly in the
underweight and obese patients. The underweight patient will
not have enough fatty padding to protect the tissues form
being pinched between the bone and the bed/chair surface.
Conversely, the overweight patient's weight will cause higher
pressures between the bone and the hard surface, thereby
increasing the risk of pressure ulcer formation.
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