Хронические раны: причины, лечение и влияние на качество жизни

Wounds that do not heal quickly
A chronic wound is a wound that does not heal in an orderly set of stages and in a predictable amount of time the way most wounds do; wounds that do not heal within three months are often considered chronic. Chronic wounds seem to be detained in one or more of the phases of wound healing. For example, chronic wounds often remain in the inflammatory stage for too long. To overcome that stage and jump start the healing process, a number of factors need to be addressed such as bacterial burden, necrotic tissue, and moisture balance of the whole wound. In acute wounds, there is a precise balance between production and degradation of molecules such as collagen; in chronic wounds this balance is lost and degradation plays too large a role. Chronic wounds may never heal or may take years to do so. These wounds can cause patients severe emotional and physical stress and create a significant financial burden on patients and the whole healthcare system. Acute and chronic wounds are at opposite ends of a spectrum of wound healing types that progress toward being healed at different rates.

Chronic wound patients often report pain as dominant in their lives. It is recommended that healthcare providers handle the pain related to chronic wounds as one of the main priorities in chronic wound management (together with addressing the cause). Six out of ten venous leg ulcer patients experience pain with their ulcer, and similar trends are observed for other chronic wounds. Persistent pain (at night, at rest, and with activity) is the main problem for patients with chronic ulcers. Frustrations regarding ineffective analgesics and plans of care that they were unable to adhere to were also identified.

In addition to poor circulation, neuropathy, and difficulty moving, factors that contribute to chronic wounds include systemic illnesses, age, and repeated trauma. The genetic skin disorders collectively known as epidermolysis bullosa display skin fragility and a tendency to develop chronic, non healing wounds. Comorbid ailments that may contribute to the formation of chronic wounds include vasculitis (an inflammation of blood vessels), immune suppression, pyoderma gangrenosum, and diseases that cause ischemia. Cancer, especially squamous cell carcinoma, may also form as the result of chronic wounds, probably due to repetitive tissue damage that stimulates rapid cell proliferation. Children who are repeatedly seen for a wound that does not heal are sometimes found to be victims of a parent with Munchausen syndrome by proxy, a disease in which the abuser may repeatedly inflict harm on the child in order to receive attention. Periwound skin damage caused by excessive amounts of exudate and other bodily fluids can perpetuate the non healing status of chronic wounds. Maceration, excoriation, dry (fragile) skin, hyperkeratosis, callus and eczema are frequent problems that interfere with the integrity of periwound skin. They can create a gateway for infection as well as cause wound edge deterioration preventing wound closure.

Chronic wounds may affect only the epidermis and dermis, or they may affect tissues all the way to the fascia. the extracellular matrix (ECM), and cytokines that speed healing. However, soluble mediators of the immune system (growth factors), cell based therapies and therapeutic chemicals can propagate coordinated healing. It has been suggested that the three fundamental factors underlying chronic wound pathogenesis are cellular and systemic changes of aging, repeated bouts of ischemia reperfusion injury, and bacterial colonization with resulting inflammatory host response.

Since more oxygen in the wound environment allows white blood cells to produce ROS to kill bacteria, patients with inadequate tissue oxygenation, for example those who developed hypothermia during surgery, are at higher risk for infection. Like ischemia, bacterial colonization and infection damage tissue by causing a greater number of neutrophils to enter the wound site. In addition, patients that carry drug resistant bacterial strains such as methicillin resistant Staphylococcus aureus (MRSA) have more chronic wounds. Fibroblast gene expression is different in chronic wounds than in acute wounds. and damages growth factors, fibronectin, and factors that inhibit proteases.

If a chronic wound becomes more painful this is a good indication that it is infected. A lack of pain however does not mean that it is not infected. Diabetics have a 15% higher risk for amputation than the general population Pressure ulcers are caused by ischemia that occurs when pressure on the tissue is greater than the pressure in capillaries, and thus restricts blood flow into the area. There is insufficient evidence to use silver containing dressings or topical agents for the treatment of infected or contaminated chronic wounds. The challenge of any treatment is to address as many adverse factors as possible simultaneously, so each of them receives equal attention and does not continue to impede healing as the treatment progresses.

Persistent chronic pain associated with non healing wounds is caused by tissue (nociceptive) or nerve (neuropathic) damage and is influenced by dressing changes and chronic inflammation. Chronic wounds take a long time to heal and patients can experience chronic wounds for many years. Chronic wound healing may be compromised by coexisting underlying conditions, such as venous valve backflow, peripheral vascular disease, uncontrolled edema and diabetes mellitus. If wound pain is not assessed and documented it may be ignored and/or not addressed properly. It is important to remember that increased wound pain may be an indicator of wound complications that need treatment, and therefore practitioners must constantly reassess the wound as well as the associated pain. Optimal management of wounds requires holistic assessment. Documentation of the patient's pain experience is critical and may range from the use of a patient diary, (which should be patient driven), to recording pain entirely by the healthcare professional or caregiver. Effective communication between the patient and the healthcare team is fundamental to this holistic approach. The more frequently healthcare professionals measure pain, the greater the likelihood of introducing or changing pain management practices. At present there are few local options for the treatment of persistent pain, whilst managing the exudate levels present in many chronic wounds. Important properties of such local options are that they provide an optimal wound healing environment, while providing a constant local low dose release of ibuprofen while worn. If local treatment does not provide adequate pain reduction, it may be necessary for patients with chronic painful wounds to be prescribed additional systemic treatment for the physical component of their pain. Clinicians should consult with their prescribing colleagues referring to the WHO pain relief ladder of systemic treatment options for guidance. For every pharmacological intervention there are possible benefits and adverse events that the prescribing clinician will need to consider in conjunction with the wound care treatment team.

Blood vessels constrict in tissue that becomes cold and dilate in warm tissue, altering blood flow to the area. Thus keeping the tissues warm is probably necessary to fight both infection and ischemia. In addition to killing bacteria, higher oxygen content in tissues speeds growth factor production, fibroblast growth, and angiogenesis.

Since chronic wounds underexpress growth factors necessary for healing tissue, chronic wound healing may be speeded by replacing or stimulating those factors and by preventing the excessive formation of proteases like elastase that break them down. Another way is to spread onto the wound a gel of the patient's own blood platelets, which then secrete growth factors such as vascular endothelial growth factor (VEGF), insulin like growth factor 1–2 (IGF), PDGF, transforming growth factor β (TGF β), and epidermal growth factor (EGF). Since levels of protease inhibitors are lowered in chronic wounds, some researchers are seeking ways to heal tissues by replacing these inhibitors in them. The incidence is 0.78% of the population and the prevalence ranges from 0.18 to 0.32%. As the population ages, the number of chronic wounds is expected to rise. Ulcers that heal within 12 weeks are usually classified as acute, and longer lasting ones as chronic.