VOL: 98, ISSUE: 25, PAGE NO: 53
Anne Wilson, RGN, BSc, is tissue viability nurse, Royal Alexandra Hospital, Paisley
The development of hospital-acquired pressure ulcers on the heel is a well-acknowledged problem (Donnelly, 2001). In fact, after the sacrum the heels are the second most common anatomical site for the development of ulcers (Cheneworth et al, 1994; Meehan, 1994), and their incidence has increased steadily over the past few decades (Collier, 2000).
Although tissue breakdown is a complex multifactorial process, the focus with pressure ulcer development in the heels is on extrinsic factors such as pressure, shear and friction, with the most plausible explanation being the failure to relieve pressure. While many advances, such as pressure-relieving mattresses and beds, have greatly reduced the incidence of sacral ulcers (Blasczczyk et al, 1998). Krasner (1987) recognised that, even with pressure reduction, most support surfaces do not adequately relieve heel pressure.
Pressure ulcers may form when heel pressure on the mattress exceeds the capillary closing pressure and the heel position is not changed frequently enough (Blasczczyk et al, 1998). The heel is at increased risk of ulceration as it has a relatively low resting blood perfusion level if subjected to lower pressures than 32mmHg (Donnelly, 2001).
Patients with limited mobility due to possible motor or sensory problems, fractures of the lower limbs and those under heavy sedation are at particular risk (Wheeler, 1997). It is widely recognised that elderly patients with orthopaedic problems are predisposed to developing heel pressure ulcers, as they are likely to undergo long periods of immobility. For example, after a femoral fracture patients cannot bear weight and are bed-fast on their back, continually subjecting the same body sites to pressure until after surgery.
Cheney (1993) suggests this problem is compounded by orthopaedic surgical procedures requiring long periods in the operating room and in recuperation. To prevent the development of heel ulcers, therefore, predisposing factors must be identified, minimised and/or relieved (Blasczczyk et al, 1998).
Numerous heel pressure-reducing devices have been developed that decrease the amount of pressure exerted on a bony prominence by dispersing the pressure over a larger surface area.
Price et al (1999) reported on a study to determine the effectiveness of a new low-unit-cost support system in patients at very high risk of developing pressure ulcers. This randomised controlled trial involved 80 patients with fractured neck of femur. A low-pressure inflatable mattress and cushion (Repose) was allocated to one group, while the second was allocated a dynamic flotation mattress (Nimbus II) and an alternating-pressure cushion (Alpha-Trancell). No statistically significant difference was found at any point between the low-pressure overlay system and the dynamic support system. The low-pressure overlay appeared to offer a similar level of benefit in preventing the development of pressure ulcers and had the potential for major cost reduction.
The Repose foot/heel protector
Repose foot protectors are designed specifically to minimise the risk of pressure damage to heels. They come in the form of splints made of Platilon, a polyurethane material with unique stretch, thermal and vapour-permeable properties. They are most effective when the patient is recumbent, semirecumbent or upright while on bed-rest, as the heels are supported above a void and therefore close to zero pressure, while the malleoli are protected by air-filled compartments.
The foot protectors are inflated using a hand-help pump. A valve ensures they are inflated to the correct pressure with no chance of over-inflation. This provides a pressure-reducing splint where the weight of the lower leg is redistributed over a wider area.
Background to the study
A number of elderly patients being transferred from the Royal Alexandra Hospital’s orthopaedic unit postoperatively to the rehabilitation wards had developed nosocomial pressure ulcers on their heels. This resulted in increased time and money being spent on dressing changes, while problems with mobilisation were hindering rehabilitation.
Heel pressure ulcers increase morbidity and costs (Cheney, 1993) and can cause immeasurable pain and distress to the patient.
To ascertain the extent of the problem a three-month report on the incidence of pressure ulcers was compiled. The overall incidence was reported at 5.6% of the total number of admissions; 47% of all ulcers were on the heel - a total of 29 heel ulcers. When these figures were broken down, 18 (62%) of these ulcers had been acquired while in the orthopaedic unit. It was also noted that 13 ulcers present on admission to the unit had been inherited from other hospital wards or care facilities.
All patients reported with nosocomial heel ulcers were assessed on admission or during the three-month study period as having a high or a very high Waterlow Score. All but one hospital-acquired ulcer occurred in the two larger 30-bed wards that admitted all orthopaedic emergencies, the majority of which are elderly patients with fractured neck of femur.
With these patients the leg with orthopaedic trauma was generally placed in a foam trough. These are of a standard length, and in many cases the heel rests on the foam surface, sustaining high pressures. In the cases where the other leg was unaffected, unless the patient was on a dynamic pressure-relieving mattress there were no set guidelines for relieving the pressure from this heel.
A comparison between ulcer development in the affected and unaffected legs was recorded. Exactly 50% of the heel ulcers were on the affected legs and 50% on the unaffected side. The ulcers acquired during hospitalisation within the study period were graded using the Stirling Classification Scale and ranged from stage 1:1 to stage 2:4. The three heel ulcers reported as stage 3:4 were present on admission to the ward.
Evaluation of the product
The evaluation of the Repose foot/heel protectors was carried out over a three-month period. Inclusion criteria selected patients who:
- Had sustained a fractured neck or shaft of femur;
- Were anticipated to be on bed-rest for 24 hours or more and were over 70 years old;
- Had a spinal injury (regardless of age).
The limb (whether leg with orthopaedic trauma or not) was excluded from the study, if on admission:
- The heel had a ulcer classified as stage 3 or greater;
- The leg was in a plaster of Paris cast;
- Specific treatment regimens prescribed by the patient’s consultant would not allow Repose boots to be worn (for instance, traction or external fixation).
The evaluation took the following format: patients were fitted with a pair of Repose boots on admission to the ward. Heels were reviewed daily for signs of pressure or friction damage and recorded on the data sheet. If the patient developed a stage 2 ulcer during the study the use of the boots was discontinued and preventative management was reassessed.
If the patient had to be taken out of the study for any other reason this was documented on the data form. Otherwise the Repose boots were worn at all times when the patient was on bed rest until discharge from the ward or transfer back to referring hospital.
Over the duration of the evaluation period a total of 38 patients wore the boots on both heels, giving potential data on 76 heels. On admission 63 (83%) heels were recorded as having stage 1 pressure damage. Seven (31%) heels showed some deterioration while wearing the boots, six of which deteriorated from zero damage to a stage 1 ulcer and one heel deteriorated from stage 1 to a stage 2 ulcer (all ulcers were graded using the Stirling Classification Scale). However, before completion of the study all seven of these ulcers had recovered with continued use of the Repose heel protector boots.
Twenty-six patients had protectors in situ for one to 10 days, six for between 11 and 20 days, and a further six patients wore the boots for up to 30 days. Three patients did not tolerate the Repose boots and were removed from the study.
When the protectors were not in use they were deflated, washed thoroughly in general purpose detergent and stored in cardboard cylinders in a small cupboard in the ward duty room. The staff using the equipment found the protectors simple to use and easy to wash and store, thus maintaining high standards of cleanliness.
Over the three-month evaluation period six single heel protectors were damaged and had to be disposed of. Two of these had been caught in cot-sides and four had torn due to the application or removal of adhesive tape used to secure the boots. The latter problem was overcome by loosely applying a Tubinet length over the splint and leg, to be used with restless or confused patients.
It is difficult to compare the incidence study on pressure ulcer development on the heels of orthopaedic patients, as previously discussed, with the findings uncovered in this evaluation. However, there are similarities in the patient groups with regards to age, orthopaedic problem and the fact that all were bedridden for a period and had a high Waterlow Score (>15) on admission.
When looking at the use of Repose boots from patients’ admission to discharge during the study there is a 100% success rate in the prevention of further damage due to pressure. However, agitated patients pose a special concern. Although these patients are also at risk of developing heel ulcers, the aetiology is a friction/shear phenomenon and not pressure (Blasczczyk et al, 1998), which would be difficult to overcome using the protectors alone.
Applying heel-protecting materials (De Keyser et al, 1994) can markedly reduce vertical pressure. Also, heels require additional protection beyond the use of special beds and mattress overlays. In order to provide continuous heel suspension, clinicians must consider their proper fit, turning schedules, the patient’s position, patient activity and presence of additional equipment when selecting heel protection products (Tymec et al, 1997).
When considering a device to relieve pressure on the heel, several factors must be considered. These include effectiveness of the device in terms of pressure relief, the cost of the device, the ease and accuracy of application, and patient comfort.
Staff found the Repose foot/heel protectors simple to use and easy to wash and store. The patients found them comfortable to wear, and they successfully prevented pressure ulcer damage during this evaluation period.
With care these products can be a cost-effective preventative piece of equipment compared with more expensive treatment options. The staff in the ward were so impressed with the Repose boots that they continue to use them as part of the pressure ulcer prevention plan.
It has been widely recognised that elderly orthopaedic patients are predisposed to developing heel pressure ulcers. While meticulous nursing care remains the critical element in prevention of heel ulcers, the use of Repose boots in conjunction with this can enhance the maintenance of skin integrity. It is hoped to expand the use of these preventative aids to all patients at high risk of developing heel pressure ulcers.