Care and treatment of chronic wounds

Normal wound healing and risk factors

The wound healing process divides into distinct phases. The first phase, inflammation, begins immediately after tissue damage and lasts 2-5 days. When tissues suffer damage, the release of chemical mediators called cytokines triggers local hemostasis. Platelets aggregate, and serotonin and other vasoconstrictors stop bleeding. The coagulation cascade activates, converting fibrinogen to fibrin, which stabilizes the platelet plug. Prostaglandins cause local vasodilation, allowing plasma to enter the damaged tissues and form inflammatory exudate.

The proliferative phase lasts from 2 days to 3 weeks. Macrophages activate fibroblasts, which repair damaged tissues by forming collagen fibers and new capillaries, leading to the formation of granulation tissue. Fibroblasts transform into myofibroblasts, contracting the wound edges. Later epithelialization forms a new epithelium over granulation tissue, requiring a moist wound surface.

The remodeling phase can last from 3 weeks to 2 years. During this time, immature, soft collagen transforms into organized, stronger collagen, forming scars.

Acute wounds usually heal when there is no disruption in the body's function. Disrupting any physiological phase of wound healing impairs the process. For example, local tissue ischemia and neuropathy affect hemostasis and the inflammatory phase, leading to tissue necrosis. Infection increases inflammatory factors in the damaged tissues, causing edema and impairing myofibroblast function so that wound edges do not contract and collagen forms irregularly. Several factors can influence impaired wound healing, turning acute wounds into chronic ones. Common causes of non-healing wounds include chronic venous insufficiency, peripheral arterial disease, and diabetes mellitus (5).

Risk factors

Risk factors can be described by the English acronym DIDN'T HEAL:

• D – Diabetes: Long-standing or poorly controlled diabetes increases the risk of complications such as neuropathy and micro- and macrovascular changes that affect wound healing. Even short-term poor diabetes control increases the risk of chronic wounds and complicates their healing.
• I – Infection: Infection worsens collagen fiber production, leading to their lysis.
• D – Drugs: Glucocorticoids hinder fibroblast proliferation and collagen synthesis.
• N – Nutrition: Adequate protein, vitamins A, C, and zinc intake are important for normal wound healing.
• T – Tissue necrosis: Local or systemic ischemia causes tissue necrosis.
• H – Hypoxia: Local vasoconstriction, influenced by excessive sympathetic nervous system activity, leads to hypoxia. Blood flow to the wound decreases, causing pain and hypothermia.
• E – Excessive tension: Excessive tension on wound edges causes local tissue ischemia and necrosis.
• A – Another wound: The presence of multiple wounds often limits the body's resources to promote healing, impeding the healing of all wounds.
• L – Low temperature: Low temperature can affect the healing process.

Other risk factors include smoking, age, and immobilization. Healthcare providers should identify possible causes that may affect wound healing when treating wounds in both outpatient and hospitalized patients.

What to pay attention to when treating chronic wounds

The wound healing society recommends healthcare professionals treating and dressing wounds focus on the following factors:

• Wound tissues: Timely notice dead, necrotic tissues, the appearance of surrounding tissues, redness, rashes.
• Inflammation or infection: If the patient feels increasing, pulsating pain, and a foul odor starts to come from the wound, suspect infection.
• Wound secretions: Clarity, odor, quantity of secretions. Serous secretion is light in color, odorless, watery, typically appearing during the inflammatory wound healing phase. Large amounts of this secretion could indicate infection. Hemorrhagic secretion includes fresh blood and differs from acute wounds. Serosanguineous secretion is watery, reddish, often observed when changing wound dressings. Suspect infection when serous secretion with pus emerges from the wound, typically a darker yellow, thick, with a foul odor.

Wound edges: Evaluate blood circulation, whether wound edges are contracting, reepithelializing.

If negative changes occur, and the wound heals poorly despite addressing risk factors, refer the patient to a specialist (surgeon, vascular, or plastic and reconstructive surgery specialist) (6).

Guidelines for treating chronic wounds

In 2017, the Canadian Wound Organization released new Wound Treatment and Prevention Guidelines. They recommend establishing treatment goals for each wound. If multiple risk factors influence chronic wounds, use products for skin protection and adjust these risk factors. The main goals include stabilizing wound healing, reducing bacterial entry, timely and appropriate wound dressing, controlling symptoms (pain, odor), and returning the patient to work as quickly as possible (7).

Treatment and care of chronic wounds

To ensure effective wound treatment, maintain a well-vascularized wound bed and surrounding tissues, remove non-viable, necrotic tissues, keep the wound moist, and free of infection signs. Effective treatment forms granulation tissue and encourages wound edges to epithelialize and contract towards each other. Each wound contains a certain number of bacteria, but not all are infected. Antibiotic therapy should not be prescribed to all patients, as no scientifically proven studies demonstrate the benefits of prophylactic antibiotic therapy for non-infected chronic wounds. When signs of infection are absent, antibiotics do not accelerate wound healing. Washing wounds thoroughly when changing dressings is crucial. Use warm saline solution for this purpose. Scientific research shows no significant difference between tap water and saline solution, making both suitable for daily wound care. Washing wounds under strong pressure can damage surrounding healthy tissues and cause local ischemia. Many antiseptic and antimicrobial solutions are partially cytotoxic, irritating tissues, slowing down wound healing, and causing allergies. Use povidone-iodine solutions, as this antimicrobial solution effectively reduces bacteria, is non-toxic to tissues, stimulates healing, and ensures wound moisture. Povidone-iodine solution acts on all gram-negative and gram-positive bacteria. Although silver is toxic to bacteria, studies have not shown that silver dressings significantly impact better wound healing compared to dressings without silver (12).

Honey has been used for wound healing since ancient times. It is not cytotoxic, eliminates unpleasant odors, and has a broad-spectrum antimicrobial effect due to its high osmolarity and hydrogen peroxide concentration. Honey can be found in gels, creams, and colloidal dressings. However, there is still a lack of statistically reliable data to support the suitability of honey dressings for all types of wounds. It is best to choose them for treating burn wounds and avoid using them for chronic venous ulcers (13). Studies have also focused on the local application of timolol for treating chronic wounds and burns. Beta-adrenoreceptor blockers influence keratinocyte activity, improving cell migration and epithelialization (14).

Proper wound care and selected dressings are crucial for wound healing. A well-chosen dressing ensures faster healing, stronger, and smaller scars. No single dressing suits all wounds. Evaluate the wound exudate, signs of infection, speed, and stage of remodeling and epithelialization. Follow general principles when selecting dressings (15):

• After removing dead tissues, use hydrogel dressings.
• During the granulation phase, choose less adherent, moisture-retaining dressings (hydrocolloids).
• During epithelialization, select the least traumatic dressings to avoid damaging and tearing formed tissues when changing the dressing.

Summary

Treating chronic wounds is complex, requiring an assessment of not only the wound itself but also the patient's underlying diseases, dietary and lifestyle habits. Evaluate the type of wound, the amount of secretion, and signs of infection when selecting the most suitable dressings. Daily wound care positively impacts healing. Choose the least traumatic solutions for washing wounds. Active participation in wound care by doctors, nursing staff, the patient, and their family members is crucial.