Chapter 8 Conclusions
8.2 The Model
This model explained substantial variance in the healing rate o f venous leg ulcers. However, 47% o f the variance in the healing rate has not been explained by this model in this group. The stability o f the identified explanatory variables (liposclerosis, wound
characteristics, horizontal limb hours, perceptions o f pain in mobility) was supported in venous and the all disease models. Eighty percent o f subjects had some venous skin changes. Variability in cognitive factors was reduced and not significant in the small group with venous and mild to moderate arterial disease. Low proportions o f explained variance in the all disease model could be a consequence o f the diversity in other factors not being measured in the model.
The biomedical approaches to leg ulcer management in older people have been found to be powerful influences, but not the entire story. The important indicators o f poorer healing in this study in venous disease reflect the nature o f the disease, with severe changes in the skin structure (liposclerosis), and reduced mobility with the associated detrimental effects o f certain limb positions. Perceptions o f pain in mobility may also be resulting in reduced activity. Specific therapeutic activities have little effect on healing in this community sample.
Two possible explanations for the ineffectiveness o f the compression therapy and limb elevation suggest themselves. First, it is possible that high levels o f limb compression in inactive clients and limb elevation in clients affected by osteoarthritis, are counterproductive. Second, the form in which these interventions are implemented may be uneven and ineffective.
The findings o f this study raise questions about the appropriateness o f the usual interventions in an older, immobile, group o f leg ulcer sufferers living in the community. Compression therapy is recommended for ambulatory patients (The Alexander House Group, 1992). But this sample, like other larger community studies, demonstrates significant limitations to mobility. Additionally, over half this sample has osteoarthritis. These people would often have difficulty in managing compression stockings or bandages. Swelling o f joints and surrounding areas is not uncommon, and this factor, together with the oedema commonly experienced with venous hypertension, make achievement o f appropriate pressure gradients and ankle pressures o f 40 - 50 mmHg difficult. These people are unlikely to be able to sustain limb elevation at a reasonable height for a substantial length o f time if hip and knee joints are affected by osteoarthritis. If limb compression and elevation are the major therapies applicable to this group, there is a mismatch between clients’ likely ability to manage these therapies, and the nature o f the therapy. The costs involved in bandages and dressings were often stated as a prohibitive factor, resulting in the use o f over-stretched, ineffective bandages.
This study has illustrated some o f the problems o f implementing in the community, treatments that are based on research findings from clinic studies. First, clinic studies o f older people are often carried out on younger samples than those seen by district nurses. When nurses attempt to apply the scientific principles to the patient, practical problems arise. The conditions under which treatments used in trials are performed are often dissimilar to how these apply in practice. Compression bandaging, known to vary
between clinicians, is precisely measured in most trials, but no such equipment is provided with bandages for clinicians in the clinical setting. Nurses may try to adapt the demonstrated scientific principles— perhaps encouraging people to rest if they can’t keep their legs elevated, lessening compression to a tolerable level for older arthritic people— with potentially negative outcomes.
Some discussion on the notion o f rest (without limb elevation) and healing has particular bearing on this study. When we are sick we rest to allow the body to heal. This is a fundamental principle o f nursing practice originating from the early teachings o f Florence Nightingale (1969). In older people, immobility is associated with reduced independence, and may indirectly be related to impressions o f ill-health. The relationship o f rest to healing may not apply in this case.
A major theme throughout this study has been that leg ulcers result from alterations in blood flow— venous and arterial and combinations o f these systems. Limb position, and possibly changes in limb position, alter blood flow and available oxygen. This may be a major key to this problem. Strategies that mobilise patients, reduce pressure and enhance venous blood return to the heart, provide adequate intermittent blood flow to the lower limb, and are suitable for older people, are yet to be found. All this has to be achieved in relatively immobile people. Regular changes o f position, appropriate exercises (not explored in this study), altered environments that allow these patients to elevate and move limbs, precise tailoring o f compression therapy to individual venous hypertension, and a more appropriate form o f compression therapy need to be considered.
Dressings, or scores o f dressing attributes, were not demonstrably related to healing. Wound characteristics were related to healing. Nurses have often focussed on dressing the wound and observed improving wound characteristics. A plausible explanation may be that the subsequent attribution o f change being as a result o f the dressing, may be ignoring other more influential factors that are also varying.