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Is wound healing delayed in older patients?

Pauline Beldon
Tissue Viability Nurse Consultant
Epsom & St Helier University Hospitals NHS Trust

Wound healing is recognised as a normal response to injury. It is a complicated process, which involves interacting cells, cytokines (chemical messengers), enzymes and proteins in sequences that appear to occur both sequentially and simultaneously, as different areas of a wound bed progress at different speeds.(1) The stages of wound healing can be summarised into recognisable stages:

  • Inflammation: 0-3 days.
  • Destruction: 1-6 days.
  • Proliferation: 3-24 days.
  • Maturation: 24 days to 2 years.

As individuals age, it is inevitable that this is evident in the skin and subcutaneous tissue. The structure and function of the skin are inextricably linked; consequently, structural changes due to ageing may lead to functional impairment.(3) Nevertheless, the skin continues to perform the functions of protection, absorption, secretion, excretion, thermoregulation, pigment production, sensory perception and immunity, but due to ageing it does so less efficiently. (4) The skin is the largest organ of the body and consists of two layers: the epidermis, composed primarily of dead epithelial cells whose integrity protects the body from infection and dehydration, and the dermis, which consists mainly of connective tissue.(5)
The dermis is responsible for the majority of the skin's functions, containing blood vessels (tissue repair and maintenance), sweat and sebaceous glands (skin lubrication, excretion and temperature regulation), hair follicles and sensory receptors (which locate sensory input from surroundings). Dermal papillae project into the epidermis to firmly fix the two layers together. Below the dermis is the subcutaneous tissue, which anchors the dermis to underlying tissue, cushions against impact to the body and provides heat insulation.(6)

Changes in anatomy and physiology
It is worth noting the changes that occur in the skin due to ageing, since these changes reflect both the skin's ability to heal and the greater propensity for wounding. The epidermis flattens due to loss of the papillae, which in younger skin maintains a strong connection between the epidermis and dermis at the epi-dermal junction. As a consequence, the epidermal and dermal layers peel apart more easily and are more prone to friction and shearing forces.(6) In addition, the dermis reduces in bulk due to cell reduction, and the number of dermal capillaries is also reduced, with the effect that less oxygen, nutrients and fluids are delivered to the skin.(7) Consequently, the skin becomes drier and more prone to superficial injury such as skin tears, cuts and abrasions. Sensory nerve function is also reduced in older people, and their response to pain or changes in temperature is reduced, which also increases the risk of injury.(7)
It has been reported that in older skin there is a decrease in the volume of collagen within the dermis. However, Lavker et al described what initially appeared to be an increase in the volume of collagen, but ascribed this to a reduction in the spaces between individual bundles of collagen in the dermis: the spaces are normally occupied by elastin and ground substance, ­but those decrease with age, leading to compression of collagen and a more compact appearance. (8,9) Elastin fibres give the skin its ability to recoil when stretched; however, in older skin this ability is lost as the elastin fibres degenerate, the resultant effect being that the dermis is less stretchable, less resilient, slacker and prone to wrinkling.(10)

Ageing and wound healing
A review of the literature shows there have been many studies that have strived to prove that wound healing is delayed in the elderly patient, but many of these studies are open to criticism. Carrell and DuNouy  studied the healing time for patients with open wounds; they concluded that with each progressive decade of life wound healing would be slower.(11) However, they studied first-world-war wounds of various types, which are hardly comparable, and it was also a preantibiotic era when wounds would have been more subject to infection. Controlled studies of full-thickness wound contraction and closure have been performed on rabbits, rats and dogs, all demonstrating that the older the animal, the slower the rate of wound contraction.(12-14) The question arises, however, as to whether animal studies should be extrapolated to humans.
A study by Sandblum et al on wound breaking strength suggested that less force was required to disrupt the wounds in older individuals (over 70 years) than in those younger than 70 years. However, there are many variables that need to be taken into account in experimental design, and nutritional status plays a large role in wound healing; it could be suggested that if a nutritional assessment were made of these subjects, the older individuals would be more likely to be malnourished.(15,16) In addition, the older an individual becomes, the more likely they are to have developed pathologies that are recognised to delay healing (eg, vascular disease or diabetes).(17) Similarly, Mendoza et al reported the rate of wound dehiscence to be two to three times higher in patients over the age of 60, but the study did not take into consideration variables such as body weight; obesity is linked to increased likelihood of diabetes and wound dehiscence.(18)
Formation of granulation tissue is reported to be impaired in the elderly and considered to be related to a decrease in the number of fibroblasts and collagen density, but this is also reliant upon nutritional and vascular status.(19)

Implications for practice
Nutrition has an integral role to play in wound healing; nutritional assessment is invaluable in ensuring the older individual is ingesting sufficient food and fluids to enable wound healing to progress.(20)
Changes in body temperature can deplete energy reserves; the energy required to maintain body temperature in a room that is too cold can increase the risk of poor dermal perfusion to the healing wound and body organs. In hospitals, therefore, it is vital that we adjust the heat according to our patients' needs, while in the community setting we should advise our patients to act accordingly.(21)
Reduced cardiac output is common in the elderly and can lead to peripheral oedema, which reduces local perfusion of the skin. Wound bed elevation of limbs is necessary to correct this.(17) In addition, both overhydration and underhydration may exacerbate cardiac failure, while underhydration can also lead rapidly to confusion and possible urinary tract infections, both common in the elderly.(17) Recognition of the need for fluid balance can minimise possible complications. Local and systemic perfusion of blood is vital to provide the wound area with oxygen and nutrients. For example, poor local perfusion may be associated with diabetes and peripheral vascular disease. It can also increase the possibility of infection, which, once present, will further deteriorate the wound.(22) Elderly patients need to have their awareness raised regarding the dangers in their environment. In the home, furniture may provide a source of support while mobilising, but may also cause lower limb injury as older patients are very prone to skin tears to the anterior tibia.(23) Risk assessment of the home situation should be part of the care delivered to an older patient.
Protection and maintenance of fragile, older skin is imperative to help prevent infection. Ageing skin is more vulnerable to trauma, irritation and infection, and advice regarding the continued use of soaps may be useful as they are generally astringent in nature and dry the skin.(24,25) A soap substitute such as an aqueous cream or emulsifying ointment will help to maintain skin integrity by preventing unnecessary insensible loss of moisture. An emollient oil can be added to bathing water; use of a sponge or flannel is sufficient to remove loose skin cells and debris. After washing, the application of a moisturiser will further maintain skin quality. This should be applied gently and liberally to the skin, stroked on in the direction of hair growth to prevent blocked follicles. Avoiding perfumed products is advisable.(26) Use of adhesive dressings should be kept to a minimum as their removal may cause trauma to the surrounding skin. The use of tape to hold dressings in place is not recommended as removal of the tape may also strip the epidermal layer. If a wound is producing large amounts of exudates, care needs to be taken to ensure the correct frequency of dressing change, as excessive moisture may macerate the surrounding skin, increasing skin loss and possibly even extending an existing wound.(27)

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Conclusion
While age-related changes to the skin are irrefutable, the evidence that ageing itself adversely affects wound healing is not conclusively proven. Existing studies suffer from poor experimental design in human studies, use of animal models and the lack of subject characterisation with the exclusion of disease processes. Aged skin is undoubtedly more prone to injury, so the emphasis of care must be to minimise the risk of injury and to thoroughly assess those with a wound to maximise the potential for wound healing.

References

  1. Kingsley A. Wound healing and potential therapeutic options. Prof Nurse 2002;17:539-44.                     
  2. Richey ML, Richey HK, Fenske NA. Ageing-related skin changes: ­development and clinical meaning. Geriatrics 1988;43:49-64.
  3. Tosti A, Fazzini ML, Villardita S. Quantitive changes in epidermis of aged humans. G Ital Chir Dermatol Oncol 1987;2:180-4.
  4. Marieb E. Human anatomy and ­physiology. Redwood City: Benjamin Cummings Publishing; 1995.
  5. Woodrow P. Physiological ageing: 1. Prof Nurse 1998;13:528-32.
  6. Herbert R. The biology of human ageing. In: Redfern S, editor. Nursing elderly people. Edinburgh: Churchill Livingstone; 1991.
  7. Shuster S, Black MM, McVitie E. The influence of age and sex on skin thickness, skin collagen and density.Br J Dermatol 1975;93:639-43.
  8. Lavker RM, Zheng P, Dong G. Morphology of aged skin. Dermatol Clin 1986;3:379-89.
  9. Braverman IM, Fonferko E. Studies in cutaneous ageing: 1. The elastic fiber network. J Invest Dermatol 1982;78:434-3.
  10. Carrell A, Dunouy P. Cicatrization of wounds. J Exp Biol 1921;34:339-48.
  11. Billingham RE, Russell PS. Studies on wound healing with special ­reference to the phenomenon of wound contraction in experimental wounds on rabbit's skin. Ann Surg 1956;144:961-81.
  12. Cuthbertson AM. Contraction of full-thickness skin wounds in the rat. Surg Gynecol Obstet 1959;108:421-32.
  13. Orentreich N, Selmanowitz VJ. Levels of biological functions with ageing. Trans NY Acad Sci 1969:2;992-1012.
  14. Sandblum PH, Peterson P, Muren A. Determination of the tensile strength of the healing wound as a ­clinical test. Acta Chir Scand 1953:105;252.
  15. Bannerman E, Reilly JJ, MacLennan WJ, et al. Evaluation of British anthropometric reference data for assessing nutritional state of elderly people in Edinburgh: cross sectional study. BMJ 1997;315:338-41.
  16. Jones PL, Millman A. Wound ­healing and the aged patient. Nurs Clin North Am 1990;25:263-77.
  17. Mendoza CB Jr, Postlethwaite RW, Johnson WD. Veterans Administration Cooperative Study of Surgery for Duodenal Ulcer. II. Incidence of wound disruption following operation. Arch Surg 1970;101:396-8.
  18. Kligman AM, Lavker RM. Cutaneous ageing: the differences between intrinsic ageing. J Cutan Ageing Cosmetol Dermatol 1988;1:5-12.
  19. Pinchcofsky-Devin G. Nutrition and wound healing. J Wound Care 1994;3:231-4.
  20. Madden JW, Arem AJ. Wound healing: biologic and clinical features. In: Sabiston DC Jnr, editor. Davis-Christopher textbook of surgery. Philadelphia: WB Saunders; 1981.
  21. Hunt TK. Surgical wound ­infections: an overview. Am J Med 1981;70:712-8.
  22. Singer AJ, Hollander JE, Quinn JV. Evaluation and management of ­traumatic lacerations. New Engl J Med 1997;337:1142-8.
  23. Gilchrist BA. Age-associated changes in the skin. J Am Geriatric Soc 1982;30:139.
  24. Penzer R, Finch M. Promoting healthy skin in older people. Nurs Stand 2001;15:46-52.
  25. Carr P, Carr MA. Single, blind, parallel group study of E45 cream to treat asteototic eczema. J Dermatol Treat 1997;8:33-5.
  26. Bryant RA. Saving the skin from tape injuries. Am J Nurs 1988;88:189-91.