General information on wound care
The healing of tissue damage is a requirement for the maintenance of life. Healing of a skin wound is a complex and finely controlled series of events at the cellular and molecular level.
Wound healing is divided into three phases:
- fibroplasia and
The end result of healing is a connective tissue scar which fills the wound defect and endows the healed wound with sufficient strength. Full maturation of the scar tissue of the wound requires about a year.
Wounds may be classified according to causal mechanism, conditions and energy into acute, chronic, superficial, deep, contaminated and clean wounds. Most often acute wounds are the consequence of unintentional trauma or, for example, an intentional surgical procedure which damages the skin.
A superficial wound extends maximally through skin layers only, whereas a deep wound may pierce the skin, the dermal tissue below the skin, the muscle sheath, the muscles and extend into bone or a body cavity and in addition may cause serious damage to internal organs. Typical contaminated wounds are bites, wounds from knives or broken glass and those resulting from falling or wounds and abrasions caused by other types of trauma. A wound always becomes contaminated if saliva, sand, soil etc. get into it in connection with an accident. A surgical wound is a perfect example of a clean wound.
Typical symptoms of an acute wound are pain and bleeding. The first objective is to stop the bleeding and keep the wound clean. According to the causal mechanism an acute wound may either be sewn together surgically or left open. In the case of bites or clearly contaminated wounds it is wise to confirm the patient’s immunization status. After first aid it is important to provide an optimal environment for wound healing. A dirty wound should at least be washed or as necessary cleaned mechanically (debridement, surgical revision) and protected with clean dressings. In the ideal case an acute wound heals “per primam”, when the edges of the wound are brought into contact and when there is sufficient blood flow and when infection is absent. Depending on the causal mechanism the wound will either heal or then it heals by secondary intention (per secundam) when granulation tissue forms in a wound left purposely open and the wound edges are slowly drawn together gradually reducing the surface area of the wound. Typical wounds which heal per secundam are irregular dirty wounds and bites in which the risk of wound infection is great.
If the healing of an acute wound slows or completely stops the wound may become a chronic one. A chronic wound is one where healing has become prolonged for one reason or another. A chronic wound may remain open, even for years. The tendency for a chronic wound to heal and its rate of healing are difficult to predict and even a wound which has once healed may open again.
Typically, chronic wounds are venous and arterial leg ulcers, pressure sores and diabetic leg ulcers. A chronic wound is often a secondary manifestation of some chronic disease affecting the patient. Hence the cornerstone of treatment of a chronic wound is treatment aimed at the causal aetiology of the wound. The most important precondition of healing a wound is therapy of the disease causing and maintaining it. In addition to this causal treatment an important precondition for wound healing is careful and appropriate execution of the local treatment of the wound itself. The aim of local treatment is to create optimal conditions for healing the wound. Correctly executed local treatment accelerates the healing process and prevents wound infections.
Excluding operative wounds, achieved in aseptic conditions, all wounds should be regarded as contaminated and that bacteria have invaded them. The classical manifestations of wound infection are redness, swelling, hotness, pain and accumulation of pus. The most common wound infection is with the bacterium Staphylococcus aureus. In hospital and hospice patients with many diseases less common gram positive bacteria can cause wound infections. Bacteria and funguses which do not cause infections in healthy people, may cause opportunistic infections in patients whose resistance, i.e. their immune capability, is weakened, for instance, in immunosuppressive therapy or in the context of an immunosuppressive disease. In severe infections or special cases, in addition to the local treatment, oral or intravenous antibiotic therapy is given. Before beginning antibiotic therapy bacterial culture specimens should be taken from the wound.
Cleaning of a wound (debridement)
Dead or necrotic tissue in or around the wound slows its healing and increases the risk of wound infection. Hence it is appropriate to remove necrotic tissue from the wound surgically (debridement). In many cases the necrotic tissue or cell debris in the wound can be cleaned away without surgical instruments, as part of the normal wound care.
Effective local treatment of a wound plays a very important role. The importance of local treatment is amplified especially in patients whose general condition means that they are unsuitable for surgical interventions. In practice this is so in a patient with multiple diseases, with a bad prognosis, often in long-term care institutions for whom it is unreasonable to consider extensive surgical wound revision, challenging pedicle grafts or vascular reconstruction. However, the acute and chronic wounds of such patients must be treated appropriately and as well as possible. The basis of wound treatment in these cases is to use effective means of local treatment. A good local treatment preparation provides optimal conditions and possibilities for the wound to heal, is safe and efficacious and has been well proven in practice for various wounds and in different patient groups.