Wound healing is a complex process, which includes coordination between diverse immunological and biological systems.
The Phases of Wound Healing
- Coagulation or Haemostasis: Stopping bleeding
- Inflammation: Swelling, redness, oozing of fluids to kill microbes and remove debris
- Proliferation: Deposition of collagen and fibroblast and the formation of new blood vessels
- Remodelling: Contraction of the wound area and scar remodeling.
In an acute wound the process of healing is normally predictable:
In chronic wounds, the repair process has been disrupted by infection or low immunity often due to underlying conditions such as diabetes, vascular disease, hyperglycaemia, ischemia, and neuropathy:
Wound Care
The approach on wound care is guided by the underlying etiology of each wound. The considerations include:
- Debridement, or the removal of nonvital (necrotic) tissue
- Addressing inflammation or infection
- Managing moisture levels
- Assessing the condition of the surrounding tissue
Debridement reveals healthy, well-perfused tissue, aiding in cellular proliferation and migration. Beyond clearing dead and necrotic tissue, debridement also reduces proinflammatory factors as well as extracellular traps and microorganisms within the wound.
Dressings act as a barrier against infection from microorganisms, can administer antimicrobial agents like honey and iodine, and some are designed to absorb wound exudates, thus helping to regulate moisture.
Special Cases
Diabetic Ulcers
Diabetic ulcers are also called neuropathic ulcers because peripheral neuropathy is commonly present in patients with diabetes. Peripheral neuropathy is a medical condition that causes decreased sensation of pain and pressure, especially in the lower extremities. Diabetic ulcers typically develop on the plantar aspect of the feet and toes of a patient with diabetes due to lack of sensation of pressure or injury.
Wound healing is compromised in patients with diabetes due to the disease process. In addition, there is a higher risk of developing an infection that can reach the bone requiring amputation of the area. To prevent diabetic ulcers from occurring, it is meticulous foot care the use of well-fitting shoes is vital.
Venous Ulcers
Venous ulcers are caused by lack of blood return to the heart causing pooling of fluid in the veins of the lower legs. The resulting elevated hydrostatic pressure in the veins causes fluid to seep out, macerate the skin, and cause venous ulcerations. Maceration refers to the softening and wasting away of skin due to excess fluid.
Venous ulcers typically occur on the medial lower leg and have irregular edges due to the maceration. There is often a dark-colored discoloration of the lower legs, due to blood pooling and leakage of iron into the skin called hemosiderin staining.
For venous ulcers to heal, compression dressings must be used, along with multilayer bandage systems, to control edema and absorb large amounts of drainage.
Arterial Ulcers
Arterial ulcers are caused by lack of blood flow and oxygenation to tissues. They typically occur in the distal areas of the body such as the feet, heels, and toes. Arterial ulcers have well-defined borders with a “punched out” appearance where there is a localized lack of blood flow.
They are typically painful due to the lack of oxygenation to the area. The wound base may become necrotic (black) due to tissue death from ischemia.
Wound dressings must maintain a moist environment, and treatment must include the removal of necrotic tissue. In severe arterial ulcers, vascular surgery may be required to reestablish blood supply to the area.
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