At a glance......
- 1 Normal Healthy Skin of Wounds
- 2 Types of Wounds
- 2.1 1. According to the severity, a wound can be classified as
- 2.2 Acute
- 2.3 In cases of open fracture the most used classification is Gustillo-Anderson
- 2.4 Chronic
- 2.5 2. According to level of contamination, a wound can be classified as
- 2.6 Open
- 2.7 Closed
- 2.8 3. According to the Visuality, a wound can be classified as
- 2.9 Internal Wounds
- 2.10 External Wounds
- 3 Causes of Wound
- 4 Symptoms of Wound
- 5 Diagnosis of Wound
- 6 Treatment of Wound
- 7 Complication of Wound Healing
Penetration Wounds/Wounds are defined as a disruption of the normal structure and function of skin and underlying soft tissue that is caused by trauma or chronic mechanical stress (e.g., decubitus ulcers). Wounds can be broken down into acute or chronic, and open or closed. Wound treatment is performed according to pathology, the extent, and circumstances of the lesions. To heal, the wound needs to have a vascular supply, be free of necrotic tissue, clear of infection, and moist. General wound treatment includes surgical wound closure, open wound treatment, and plastic reconstruction of skin defects. In addition, infectious or concomitant disease prevention should be considered (e.g., antibiotic therapy, vaccines for tetanus and rabies, diabetes control).
A wound is damaged or disruption to the skin and, before treatment, the exact cause, location, and type of wound must be assessed to provide appropriate treatment.[rx][rx][rx] Each clinician will have widely differing and distinct opinions and understanding of wound care depending on their prior experience. The reason for this because of the widely differing and distinct types of wounds, each with their etiology. An ostomy nurse will have a completely different approach to wound care that will require an orthopedic surgeon who deals with trauma and both will be far different from a dermatologist who treats burn victims. Nevertheless, each of these healthcare providers is performing wound care. How do professionals then approach wound assessment when the causes are so diverse? Below are some basic questions to ask during a wound assessment to best classify and treat a wound presenting in a clinical setting.
Normal Healthy Skin of Wounds
As the interface between the environment and body, the skin has several distinct functions. It protects the underlying tissues from abrasions, the entry of microbes, unwanted water loss, and ultraviolet light damage. Tactile sensations of touch, pressure, and vibration, thermal sensations of heat and cold, and pain sensations all originate in the skin’s nervous system. The body’s thermoregulation relies on the skin’s ability to sweat and to control the flow of blood to the skin to increase or decrease heat loss. The skin’s functions are performed by three distinct tissue layers: a thin outer layer of cells called the epidermis, a thicker middle layer of connective tissue called the dermis, and an inner, subcutaneous layer. The outer layers of the epidermis are composed of flattened, cornified dead keratinocytes that form a barrier to water loss and microbe entry. These cells are derived from a basal layer of constantly dividing keratinocytes that lies next to the dermis. The epidermis does not contain nerves or blood vessels and obtains water and nutrients through diffusion from the dermis. The dermis is composed mostly of collagen fibers and some elastic fibers both produced by fibroblasts and, along with water and large proteoglycan molecules, makes up the extracellular matrix. This layer of the skin provides mechanical strength and a substrate for water and nutrient diffusion; it contains blood vessels, nerves, and cells involved in immune function, growth, and repair. The dermis also contains sweat glands, oil glands, and hair follicles. The subcutaneous layer is composed of adipocytes that form a thick layer of adipose tissue.[rx]
Types of Wounds
Each of the potential underlying causes must be addressed for the wound to heal. Before determining the underlying cause, it is important to determine what type of wound the patient has. These subclassifications can be acute or chronic.[rx][rx][rx]
1. According to the severity, a wound can be classified as
Clinicians assess acute wounds by the method of injury and damage to the soft tissues and bony structures. In crush or high impact injuries, there is an area of demarcation which is not fully recognized until sometimes as much as a week or 2 later. For this reason, it is important to determine the method of injury and to keep in mind that the wound seen is not necessarily the entirety of the wound which will be present in a week. In these cases, the patient and their family should be educated on this progression to prevent frustration and misunderstanding.
For all acute types of wounds, it is important to determine the length of time since injury (days or hours), the involvement of neurovascular supply, muscle, tendon, ligament, and bony involvement, and the likelihood of contaminants in the wound. Also of importance is when the patient had their last tetanus shot. CLinicians should start antibiotics if the wound is severely contaminated or if it is longer than 3 hours since the injury. All underlying tissue should be repaired if possible, and the wound should be irrigated to remove contaminants and bacteria.
In cases of open fracture the most used classification is Gustillo-Anderson
- Type 1 – Clean wound, less than one cm with minimal soft tissue damage, adequate soft tissue coverage of bone, and no periosteal stripping
- Type 2 – Wound with moderate contamination, greater than one cm with moderate soft tissue damage, adequate soft tissue coverage of bone, and no periosteal stripping
- Type 3A – Wound with significant contamination, with significant soft tissue damage, adequate soft tissue coverage of bone, and periosteal stripping is present
- Type 3B – Wound with significant contamination, with significant soft tissue damage, unable to cover bone with soft tissue (requiring graft), and periosteal stripping
- Type 3C – Similar to type A or B, however with Arterial damage requiring repair
If a wound becomes arrested in progression through the normal stages of inflammation and wound healing and remains open, then this becomes a chronic wound. While there is no consensus as to when a wound becomes chronic, a study by Sheehan et. al determined that in diabetic wounds, the degree of healing at 4 weeks is a strong predictor of 12 week healing, suggesting that those wounds which have not healed approximately 50% in 4 weeks are likely to have an arrested healing process, and therefore are chronic.[rx][rx]
In the chronic setting, the main goal is to identify why the wound is not healing and to fix this obstacle or obstacles.
There are a limited number of reasons a wound becomes chronic; however, once these reasons are rectified, the wound resumes its natural course of healing.
- Arterial – Is there enough blood flow? Generally speaking, an ABI of less than 50 mm Hg, or an absolute toe pressure less than 30 mm Hg (or less than 50 mm Hg for persons with diabetes) indicates critical limb ischemia and predicts failure of wounds to heal.
- Venous – Pressure-induced changes in blood vessel wall permeability then lead to leakage of fibrin and other plasma components into the perivascular space. Accumulation of fibrin has direct and negative effects on wound healing as it down-regulates collagen synthesis.
- Infection – Underlying infectious processes including cellulitic and osteomyelitis processes will inhibit wound healing. Culturing for aerobic, anaerobic, and fungal pathogens is recommended.
- Pressure – Increased pressure to the area of concern will destroy new tissue growth and prevent proper perfusion of blood to the wound site. These areas need to be offloaded to avoid pressure in the area.
- Oncologic – Always biopsy areas of concern in nonhealing wounds, as this can be an atypical presentation of some types of malignancies.
- Systemic – There are multiple systemic diseases which inhibit wound healing, with diabetes being the most common culprit. It has been determined that uncontrolled blood glucose levels suppresses the body’s normal inflammatory response, as well as causing microvascular disease which limits healing.
- Nutrition – While serum albumin has not been found to be a good predictor of wound healing, there is some evidence that protein malnutrition, as well as insufficient levels of certain vitamins and minerals, will limit the body’s ability to heal chronic wounds.
- Pharmacological – Hydroxyurea has been reported in multiple instances to cause nonhealing ulcerations.
- Self-inflicted/psychosocial – There are instances where a patient is causing the ulceration, either on purpose or as a result of noncompliance. This is often the hardest factor to spot and overcome, but must always be a consideration.
2. According to level of contamination, a wound can be classified as
- Clean wound – made under sterile conditions where there are no organisms present, and the skin is likely to heal without complications.
- Contaminated wound – usually resulting from accidental injury; there are pathogenic organisms and foreign bodies in the wound.
- Infected wound – the wound has pathogenic organisms present and multiplying, exhibiting clinical signs of infection (yellow appearance, soreness, redness, oozing pus).
- Colonized wound – a chronic situation, containing pathogenic organisms, difficult to heal (i.e. bedsore).
Open wounds can be classified according to the object that caused the wound
- Incisions or incised wounds – caused by a clean, sharp-edged object such as a knife, razor, or glass splinter.
- Lacerations – irregular tear-like wounds caused by some blunt trauma. Lacerations and incisions may appear linear (regular) or stellate (irregular). The term laceration is commonly misused in reference to incisions.[rx]
- Abrasions (grazes) – superficial wounds in which the topmost layer of the skin (the epidermis) is scraped off. Abrasions are often caused by a sliding fall onto a rough surface such as asphalt, tree bark or concrete.
- Avulsions – injuries in which a body structure is forcibly detached from its normal point of insertion. A type of amputation where the extremity is pulled off rather than cut off. When used in reference to skin avulsions, the term ‘degloving’ is also sometimes used as a synonym.
- Puncture wounds – caused by an object puncturing the skin, such as a splinter, nail or needle.
- Penetration wounds – caused by an object such as a knife entering and coming out from the skin.
- Gunshot wounds – caused by a bullet or similar projectile driving into or through the body. There may be two wounds, one at the site of entry and one at the site of exit, generally referred to as a “through-and-through.”
Closed wounds have fewer categories, but are just as dangerous as open wounds:
- Hematomas (or blood tumor) – caused by damage to a blood vessel that in turn causes blood to collect under the skin.
- Hematomas that originate from internal blood vessel pathology are petechiae, purpura, and ecchymosis. The different classifications are based on size.
- Hematomas that originate from an external source of trauma are contusions, also commonly called bruises.
- Crush injury – caused by a great or extreme amount of force applied over a long period of time.
3. According to the Visuality, a wound can be classified as
Disturbance of the different regulating systems of the human body can lead to wound formation, and may include the following:
- Impaired circulation – This can be from either ischemia or stasis. Ischemia is the result of reduced blood supply caused by the narrowing or blockage of blood vessels, which leads to poor circulation. Stasis is caused by immobilization (or difficulty moving) for long periods or failure of the regulating valves in the veins, which leads to blood pooling and failing to flow normally to the heart.
- Neuropathy – This is seen mostly in cases of prolonged uncontrolled diabetes mellitus, where high blood sugars, derivative proteins and metabolites accumulate and damage the nervous system. The patients are usually unaware of any trauma or wounds, mainly due to loss of sensation in the affected area.
- Medical illness – When chronic and uncontrolled for long periods (such as hypertension, hyperlipidemia, arthrosclerosis, diabetes mellitus, AIDS, malignancy, morbid obesity, hepatitis C virus, etc.), medical illnesses can lead to impairment of the immune system functions, diminishing the circulation and damaging other organs and systems.
External wounds can either be open or closed. In cases of closed wounds, the skin is intact and the underlying tissue is affected but not directly exposed to the outside environment. The following are the most common types of closed wounds:
- Contusions – These are a common type of sports injury, where a direct blunt trauma can damage the small blood vessels and capillaries, muscles and underlying tissue, as well the internal organs or bone. Contusions present as a painful bruise with reddish to bluish discoloration that spreads over the injured area of skin.
- Hematomas – These include any injury that damages the small blood vessels and capillaries resulting in blood collecting and pooling in a limited space. Hematomas typically present as a painful, spongy rubbery lump-like lesion. Depending on the severity and site of the trauama, hematomas can be small or large, deep inside the body or just under the skin.
- Crush injuries – These are usually caused by an external high-pressure force that squeezes part of the body between two surfaces. The degree of injury can range from a minor bruise to a complete destruction of the crushed area of the body, depending on the site, size, duration and power of the trauma.
Causes of Wound
- Sudden forceful fall down
- Road traffic accident
- Burn and injured suddenly
- Falls – Falling onto an outstretched hand is one of the most common causes of wound.
- Sports injuries – Many sports injury occur during contact sports or sports in which you might fall onto an outstretched hand — such as in-line skating or snowboarding.
- Motor vehicle crashes – Motor vehicle crashes can cause wound. Sometimes into many pieces, and often require surgical repair.
- Have osteoporosis – a disease that weakens your bones.
- Eave low muscle mass or poor muscle strength – or lack agility and have poor balance (these conditions make you more likely to fall)
- Walk or do other activities in snow or on the ice – or do activities that require a lot of forwarding momenta, such as in-line skating and skiing
- Wave an inadequate intake of calcium or vitamin D
- Football or soccer, especially on artificial turf
- Horseback riding
- In-line skating
- Jumping on a trampoline
Symptoms of Wound
General signs and symptoms of a wound infection include
- Redness or discoloration
- Pain, tenderness
- Scaling, itching
- Pustules, pus drainage
- Increased pain around the wound bed
- Redness or warmth
- Fever /chills or other flu-like symptoms
- Pus draining from the wound bed
- Increasing odor from the wound
- Increased firmness of skin or swelling around the wound bed
- Increasing drainage from the wound bed
- Delayed wound healing
- Discoloration of the wound bed with it turning darker in color
- Foul odor
- Increased fragility of the wound bed
- Wound breakdown /enlargement
The skin may harden or tighten in the area and red streaks may radiate from the wound. Wound infections may also cause fevers, especially when they spread to the blood.
Diagnosis of Wound
Clinicians perform wound assessment as a means for determining the appropriate treatment for an extremely diverse grouping of disease processes. Just as hypertension is not treated the same as diabetes, each of the underlying etiologies of the given wound must be identified and treated as if it were its own disease, not a blanket classification of “wound.”[rx][rx]
The initial assessment should begin with the following:
- How – How was the wound created and, if chronic, why is it still open? (underlying etiology)
- Where – Where on the body is it located? Is it in an area which is difficult to offload, or to keep clean? Is it in an area of high skin tension? Is it near any vital structures such as a major artery?
- When – How long has this wound been present? (eg., chronic or acute)
- What – What anatomy does it extend? (e.g., epidermis, dermis, subcutaneous tissue, fascia, muscle, tendon, bone, arteries, nerves)
- What – What co-morbidities or social factors does the patient have which might affect which might affect their ability to heal the wound?
- Is it life threatening?
All of these factors significantly affect the treatment plan moving forward. While there are many excellent biologics, skin grafts, and other options available, without the appropriate understanding of the nature of the wound the chances of healing decline significantly.
Issues of Concern
While some wounds are simple, the majority of wounds many clinicians encounter are caused by or complicated by some other issue.[rx][rx][rx][rx] These are a few of the possible complications from different wound types:
- A chronic wound will have a different makeup than that of an acute wound, requiring conversion for healing.
- An underlying infection will prevent wound healing even if the infection is subacute.
- A damaged or constricted arterial supply will prevent appropriate blood flow to the wound.
- A damaged venous supply will cause venous stasis.
- Physical pressure on chronic ulceration will cause repeated damage, preventing healing.
Many minor and superficial skin and wound infections are diagnosed by a healthcare practitioner based on a physical examination, sign and symptoms, and experience. A clinical evaluation cannot, however, definitively tell the healthcare practitioner which microbe is causing a wound infection or what treatment is likely to be effective. For that, laboratory testing is required.
Examples of common tests include
- Bacterial culture – This is the primary test used to diagnose a bacterial infection. Results are usually available within 24-48 hours.
- Gram stain – This is usually performed in conjunction with the wound culture. It is a special staining procedure that allows bacteria to be evaluated under the microscope. The results are usually available the same day and provide preliminary information about the microbe that may be causing the infection.
- Antimicrobial susceptibility – A follow-up test to a positive wound culture, this is used to determine the bacteria’s likely susceptibility to certain drugs and helps the healthcare practitioner select appropriate antibiotics for treatment. Results are typically available in about 24 hours. This testing can identify resistant bacteria such as MRSA.
Other tests may include
- KOH prep – This is a rapid test performed to detect fungi in a sample. The sample is treated with a special solution, placed on a slide, and examined under a microscope.
- Fungal culture – This is ordered when a fungal infection is suspected. Many fungi are slow-growing and may take several weeks to identify.
- AFB testing – This is ordered when a mycobacterial infection is suspected. Most AFB are slow-growing and may take several weeks to identify.
- Blood culture – This is ordered when infection from a wound may have spread to the blood.
- Molecular testing – to detect genetic material of a specific microbe
- Basic metabolic panel (BMP) or Comprehensive metabolic panel (CMP) – This may be ordered to detect underlying conditions that can affect wound healing, such as a glucose test to detect diabetes.
- Complete blood count (CBC) – An elevated white blood cell (WBC) count may be a sign of infection.
Treatment of Wound
- Intravenous opiates are often used as patients typically in severe pain
- Highly effective for management of pain
- Lower side effect profile than systemic analgesia
- Always calculate your toxic dose of local anesthetic to avoid local anesthetic systemic toxicity
- Closed the wounds should be placed in long leg splint and can also be placed in traction
- If open Fractures should receive antibiotics and should proceed to OR for irrigation/debridement.
- Cleaning to remove dirt and debris from a fresh wound. This is done very gently and often in the shower.
- Vaccinating for tetanus may be recommended in some cases of traumatic injury.
- Exploring a deep wound surgically may be necessary. Local anaesthetic will be given before the examination.
- Removing dead skin surgically. Local anaesthetic will be given.
- Closing large wounds with stitches or staples.
- Dressing the wound – The dressing chosen by your doctor depends on the type and severity of the wound. In most cases of chronic wounds, the doctor will recommend a moist dressing.
- Relieving pain with medications – Pain can cause the blood vessels to constrict, which slows healing. If your wound is causing discomfort, tell your doctor. The doctor may suggest that you take over-the-counter drugs such as paracetamol or may prescribe stronger pain-killing medication.
- Treating signs of infection including pain – pus and fever. The doctor will prescribe antibiotics and antimicrobial dressings if necessary. Take as directed.
- Skin Traction (Hare or Thomas) if needed
Here we review only the commonly used medications that have a significant impact on healing, including glucocorticoid steroids, non-steroidal anti-inflammatory drugs, and chemotherapeutic drugs.
- Antibiotic – Cefuroxime or Azithromycin, or Flucloxacillin or any others cephalosporin/quinolone antibiotic must be used to prevent infection or clotted blood remove to prevent furthers swelling and edema. Antibiotics and tetanus vaccination may be used if the bone breaks through the skin creating an open fracture.
- NSAIDs – Prescription-strength drugs that reduce both pain and inflammation. Pain medicines and anti-inflammatory drugs help to relieve pain and stiffness, allowing for increased mobility and exercise. There are many common over-the-counter medicines called non-steroidal anti-inflammatory drugs (NSAIDs). They include and Ketorolac, Aceclofenac, Naproxen, Etoricoxib.
- Glucocorticoid Steroids – Systemic glucocorticoids (GC), which are frequently used as anti-inflammatory agents, are well-known to inhibit wound repair via global anti-inflammatory effects and suppression of cellular wound responses, including fibroblast proliferation and collagen synthesis. Systemic steroids cause wounds to heal with incomplete granulation tissue and reduced wound contraction [rx]. Glucocorticoids also inhibit production of hypoxia-inducible factor-1 (HIF-1), a key transcriptional factor in healing wounds [rx].
- Non-steroidal Anti-inflammatory Drugs – Non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen are widely used for the treatment of inflammation and rheumatoid arthritis and for pain management. Low-dosage aspirin, due to its anti-platelet function, is commonly used as a preventive therapeutic for cardiovascular disease, but not as an anti-inflammatory drug [rx]. There are few data to suggest that short-term NSAIDs have a negative impact on healing.
- Muscle Relaxants – These medications provide relief from associated muscle spasms or injury
- Neuropathic Agents – Drugs(pregabalin & gabapentin) that address neuropathic—or nerve-related—pain. This includes burning, numbness, and tingling.
- Opioids – Also known as narcotics, these medications are intense pain relievers that should only be used under a doctor’s careful supervision.
- Topical Medications – These prescription-strength creams, gels, ointments, patches, and sprays help relieve pain and inflammation through the skin.
- Calcium & vitamin D3 – To improve bones health and healing fracture. As a general rule, men and women age 50 and older should consume 1,200 milligrams of calcium a day, and 600 international units of vitamin D a day.
- Glucosamine & Diacerein, Chondroitin sulfate – can be used to tightening the loose tendon, cartilage, ligament, and cartilage, ligament regenerates cartilage or inhabits the further degeneration of cartilage, ligament.
- Dietary supplement -to remove general weakness & improved health.
- Vitamin C – It help to cure the wounds
- Chemotherapeutic Drugs – Most chemotherapeutic drugs are designed to inhibit cellular metabolism, rapid cell division, and angiogenesis and thus inhibit many of the pathways that are critical to appropriate wound repair. These medications inhibit DNA, RNA, or protein synthesis, resulting in decreased fibroplasia and neovascularization of wounds [rx].
- Nutrition – For more than 100 years, nutrition has been recognized as a very important factor that affects wound healing. Most obvious is that malnutrition or specific nutrient deficiencies can have a profound impact on wound healing after trauma and surgery. Patients with chronic or non-healing wounds and experiencing nutrition deficiency often require special nutrients. Energy, carbohydrate, protein, fat, vitamin, and mineral metabolism all can affect the healing process [rx].
- Carbohydrates, Protein, and Amino Acids – Together with fats, carbohydrates are the primary source of energy in the wound-healing process. Glucose is the major source of fuel used to create the cellular ATP that provides energy for angiogenesis and deposition of the new tissues [rx]. The use of glucose as a source for ATP synthesis is essential in preventing the depletion of other amino acid and protein substrates [rx].
- Protein – is one of the most important nutrient factors affecting wound healing. A deficiency of protein can impair capillary formation, fibroblast proliferation, proteoglycan synthesis, collagen synthesis, and wound remodeling. A deficiency of protein also affects the immune system, with resultant decreased leukocyte phagocytosis and increased susceptibility to infection [rx]. Collagen is the major protein component of connective tissue and is composed primarily of glycine, proline, and hydroxyproline. Collagen synthesis requires hydroxylation of lysine and proline, and co-factors such as ferrous iron and vitamin C. Impaired wound healing results from deficiencies in any of these co-factors [rx].
- Arginine – is a semi-essential amino acid that is required during periods of maximal growth, severe stress, and injury. Arginine has many effects in the body, including modulation of immune function, wound healing, hormone secretion, vascular tone, and endothelial function. Arginine is also a precursor to proline, and, as such, sufficient arginine levels are needed to support collagen deposition, angiogenesis, and wound contraction [rx][rx]. Arginine improves immune function, and stimulates wound healing in healthy and ill individuals [rx]. Under psychological stress situations, the metabolic demand of arginine increases, and its supplementation has been shown to be an effective adjuvant therapy in wound healing [rx].
- Glutamine – is the most abundant amino acid in plasma and is a major source of metabolic energy for rapidly proliferating cells such as fibroblasts, lymphocytes, epithelial cells, and macrophages [rx]. The serum concentration of glutamine is reduced after major surgery, trauma, and sepsis, and supplementation of this amino acid improves nitrogen balance and diminishes immunosuppression [rx]. Glutamine has a crucial role in stimulating the inflammatory immune response occurring early in wound healing [rx]. Oral glutamine supplementation has been shown to improve wound breaking strength and to increase levels of mature collagen [rx].
- Fatty Acids – Lipids are used as nutritional support for surgical or critically ill patients to help meet energy demands and provide essential building blocks for wound healing and tissue repair. Polyunsaturated fatty acids (PUFAs), which cannot be synthesized de novo by mammals, consist mainly of two families, n-6 (omega-6, found in soybean oil) and n-3 (omega-3, found in fish oil). Fish oil has been widely touted for the health benefits of omega-3 fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The effects of omega-3 fatty acids on wound healing are not conclusive. They have been reported to affect pro-inflammatory cytokine production, cell metabolism, gene expression, and angiogenesis in wound sites [rx] . The true benefit of omega-3 fatty acids may be in their ability to improve the systemic immune function of the host, thus reducing infectious complications and improving survival [rx].
- Vitamins, Micronutrients, and Trace Elements – Vitamins C (L-ascorbic acid), A (retinol), and E (tocopherol) show potent anti-oxidant and anti-inflammatory effects. Vitamin C has many roles in wound healing, and a deficiency in this vitamin has multiple effects on tissue repair. Vitamin C deficiencies result in impaired healing, and have been linked to decreased collagen synthesis and fibroblast proliferation, decreased angiogenesis, and increased capillary fragility. Also, vitamin C deficiency leads to an impaired immune response and increased susceptibility to wound infection [rx;rx]. Similarly, vitamin A deficiency leads to impaired wound healing. The biological properties of vitamin A include anti-oxidant activity, increased fibroblast proliferation, modulation of cellular differentiation and proliferation, increased collagen and hyaluronate synthesis, and decreased MMP-mediated extracellular matrix degradation [rx].
- Vitamin E, an anti-oxidant – maintains and stabilizes cellular membrane integrity by providing protection against destruction by oxidation. Vitamin E also has anti-inflammatory properties and has been suggested to have a role in decreasing excess scar formation in chronic wounds. Animal experiments have indicated that vitamin E supplementation is beneficial to wound healing [rx, rx; rx] and topical vitamin E has been widely promoted as an anti-scarring agent. However, clinical studies have not yet proved a role for topical vitamin E treatment in improving healing outcomes [rx,rx].
- Several micronutrients – have been shown to be important for optimal repair. Magnesium functions as a co-factor for many enzymes involved in protein and collagen synthesis, while copper is a required co-factor for cytochrome oxidase, for cytosolic anti-oxidant superoxide dismutase, and for the optimal cross-linking of collagen. Zinc is a co-factor for both RNA and DNA polymerase, and a zinc deficiency causes a significant impairment in wound healing. Iron is required for the hydroxylation of proline and lysine, and, as a result, severe iron deficiency can result in impaired collagen production [rx,rx;rx, rx; rx].
Some of the unique features of each are described below.
The following dressings may be used on chronic or acute wounds depending on the nature of the wound.
- Low or nonadherent dressings – are inexpensive and allow wound exudate to pass through into a secondary dressing while helping to maintain a moist wound environment. These dressings are specially designed to reduce adherence to the wound bed. Non adherent dressings are made from open weave cloth soaked in paraffin, textiles, or multilayered or perforated plastic films. This type of dressing is suitable for flat, shallow wounds with low exudate such as a venous leg ulcer.
- Hydrocolloid dressings – are composed of adhesive, absorbent, and elastomeric components. Carboxymethylcellulose is the most common absorptive ingredient. They are permeable to moisture vapor, but not to water. Additionally, they facilitate autolytic débridement, are self-adhesive, mold well, provide light-to-moderate exudate absorption, and can be left in place for several days, minimizing skin trauma and disruption of the healing process. They are intended for use on light-to-moderate exuding, acute or chronic partial- or full-thickness wounds but are not intended for use on infected wounds. Upon sustained contact with wound fluid, the hydrocolloid forms a gel.
- Foam dressings – vary widely in composition and construction. They consist of a polymer, often polyurethane, with small, open cells that are able to hold fluids. Some varieties of foam dressings have a waterproof film covering the top surface and may or may not have an adhesive coating on the wound contact side or border. Foams are permeable to water and gas, and are able to absorb light to heavy exudate. This type of dressing is frequently used under compression stockings in patients with venous leg ulcers.
- Film dressings consist of a single – thin transparent sheet of polyurethane coated on one side with an adhesive. The sheet is permeable to gases and water vapor but impermeable to wound fluids. Film dressings retain moisture, are impermeable to bacteria and other contaminants, allow wound observation, and do not require a secondary dressing. Excessive fluid buildup may break the adhesive seal and allow leakage. Film dressings are intended for superficial wounds with little exudate and are commonly used as a secondary dressing to attach a primary absorbent dressing. The dressing may remain in place for up to seven days if excessive fluid does not accumulate. Film dressings have been used extensively to treat split-thickness graft donor sites.
- Alginate dressings – are made from calcium or calcium-sodium salts of natural polysaccharides derived from brown seaweed. When the alginate material comes into contact with sodium-rich wound exudates, an ion exchange takes place and produces a hydrophilic gel. This hydrophilic gel is capable of absorbing up to 20 times its weight and does not adhere to the wound. This dressing can remain in place for about seven days if enough exudate is present to prevent drying. This category of dressing is best suited for moist, moderate-to-heavy exuding wounds. Alginate dressings require a secondary dressing, such as a film dressing, to hold them in place and to prevent the alginate from drying out.
- Hydrofiber dressing – is composed of sodium carboxymethylcellulose fibers.[rx] The fibers maintain a moist wound environment by absorbing large amounts of exudate and forming a gel. This dressing is not intended for lightly exuding wounds. A secondary dressing is required.
- Hydrogel sheets – are three-dimensional networks of cross-linked hydrophilic polymers. Their high water content provides moisture to the wound, but these dressings can absorb small-to-large amounts of fluid, depending on their composition. Depending on wound exudate levels, hydrogels may require more frequent dressing changes, every 1–3 days, compared with other synthetic dressings. Hydrogel sheets can be used on most wound types but may not be effective on heavily exuding wounds. The gel may also contain additional ingredients such as collagens, alginate, or complex carbohydrates. Amorphous hydrogels can donate moisture to a dry wound with eschar and facilitate autolytic débridement in necrotic wounds. A second dressing may be used to retain the gel in shallow wounds.
- Polymer-based dressing – Transforming methacrylate (TMD) was compared to carboxymethylcellulose (CMC-Ag) in one study of 34 patients. The study showed that TMD, compared to CMC-Ag, was associated with lower pain scores and better patient satisfaction, but the two dressings did not differ in terms of number of dressing changes and the time to complete healing.[rx] Suprathel (a polymer-based dressing) was evaluated in a study of 72 patients, and it was compared to a polyurethane dressings (Biatain-Ibu) and a silicone dressing (Mepitel). The three dressings had similar time to re-epithelialization, but Suprathel had a significantly lower number of dressing changes compared to the two other dressings.[rx]
- Crystalline cellulose dressings – Results for the comparison between CMC-Ag and TMD are presented above.[rx] Veloderm was compared to Vaseline gauze in 96 patients.[rx] The study showed that Veloderm was associated with lower time to complete healing and number of dressing changes. The two dressings did not differ in terms of incidence of exudate, peri-lesional erythema or pain intensity.[rx]Rayon dressing was compared to Veloderm in a study of 14 patients and 28 skin graft donor sites.[rx] Rayon dressing showed lower dressing adherence to wound and lower 1st day pain score; the two dressings did not differ in terms of pain beyond day 14, hyperemia, edema and pruritus.[rx]
- Alginate dressings – The study evaluated the dressing materials in terms of time to healing, pain scores, clinical infections and hypergranulation. Results showed that the six types of dressings did not differ with statistical significance except in the following cases: first, the semi-permeable films (Tegaderm or Opsite) were associated with lower pain scores than any other dressing type; second, the hydrocolloid dressing (DuoDerm E) required lower time (seven days difference) to healing than all other dressings; finally, the gauze dressings (Adaptic or Jelonet) were associated with the highest incidence of clinical infections.[rx]
- Alginate-based dressings – were also evaluated in three other trials; the first one compared Algisite to a keratin dressing (Keramatrix).[rx]The trial showed that Algisite was associated with higher rate of epithelialization seven days after the operation than Keramatrix in patients older than 50 years; for younger patients, the rate of epithelialization did not significantly differ.[rx] Ding et al. compared time to healing and pain scores between alginate-silver dressing and hydrofiber dressing (Aquacel-A) in 10 patients and 20 donor sites; the results showed that the alginate dressing was associated with shorter time to healing and lower pain scores.[rx]The third trial compared Algisite covered by a polyurethane dressing (Opsite) to paraffin gauze dressing; the results showed that the two dressings did not differ in terms of pain scores, time to epithelialization and the assessment of general comfort. Algisite dressings required more dressing changes (34 times) than the paraffin gauze (4 times).[rx]
- Polyurethane dressings – Opsite and Tegaderm films were evaluated in Brolemann’s study, and the results were presented above. Another trial compared the Opsite dressing to a hydrofiber dressing (Aquacel-A); the results showed that Opsite was associated with lower scores of pain.[rx] The Biatain-Ibu dressing was compared to Suprathel (polymer dressing) and Mepitel (silicone dressing); the results were presented above with polymer-based dressings.[rx] Another study compared Biatain-Ibu to a gauze dressing (Jelonet), and it was reported that Biatain-Ibu was associated with lower pain and itching than Jelonet; however, the study did not report any statistical testing for the differences between interventions.[rx]
- Gauze dressings – Gauze dressings were evaluated in seven trials; the results of four trials were reported earlier in this section,[rx,rx,rx,rx]and the remaining three trials were as follows one trial compared Xeroform (gauze dressing) to a multilayer dressing and showed that Xeroform was associated with longer healing time and higher pain scores than Oxyband.[rx]The second trial compared paraffin gauze to a hydrofiber dressing (Aquacel) and reported that the paraffin gauze was associated with longer re-epithelialization time and higher pain score during dressing.[rx]The last trial compared Jelonet to a multilayer dressing as a dressing over a skin graft (receiver site); the results showed that the two dressings did not affect the time to graft take, number of nursing interventions, or post-operative infections; however, they showed that Jelonet was associated with higher pain score at the time of dressing removal.[rx]
- Hydrocolloid dressings – The efficacy of DuoDerm E was compared to six other dressing materials in Brolmann’s trial; the results of this trial were presented earlier in this section.[rx]In another trial, DuoDerm was compared to a silicone-based dressing (AWBAT-D); the trial showed that the two dressings did not differ in terms of pain scores, wound size or time to discharge, but the DuoDerm was associated with shorter time to re-epithelialization.[rx]
- Hydrofiber dressings – The efficacy of Aquacel was studied in six trials; the results of four trials were presented earlier in the section.[rx,rx,rx,rx]One of the remaining trials compared Aquacel to carbohydrate wound dressing (Glucan II), and it showed that the two interventions did not differ in terms of time to re-epithelialization, pain scores, or donor site infection.[rx]The second trial compared two different protocols of using Aquacel; in the first protocol, Aquacel dressing was covered with gauze, while in the second one, it was covered with polyurethane film (OpSite).[rx] The trial reported that the second protocol was associated with a larger number of donor sites healing at day 14 after surgery (88% versus 67%), and it was associated with lower pain during mobility the first day after operation; the two dressings did not differ in pain scores during rest at all time-point evaluations.[rx]
- Silicone dressings – Four trials evaluated the efficacy of silicone-based dressings; the result three of trials were presented earlier in this section.[rx,rx,rx] The fourth trial compared Mepitel dressing to a nylon dressing (Bridal veil) when used over a skin graft (receiver site).[rx] The results of this trial showed that Mepitel dressing was associated with less pain, easier use, and better overall experience for patients.[rx]
- Keratin dressings – The efficacy of Keranatrix was evaluated in one study the results of which were presented earlier in this section.[rx]
- Self-adhesive fabric dressing (Mefix) with or without fibrin sealant – One trial evaluated the difference between using Mefix alone or with a fibrin sealant; the trial showed that the use of fibrin sealant was associated with lower daily pain and incapacity scores, but it did not affect the time to dressing removal or the time to discharge for the hospital.[rx]
- Multilayer (combination) dressings – The efficacy of Oxyband and Allyven was evaluated in two studies the results of which were presented earlier in this section.[rx,rx]
- Nylon dressings – The efficacy of Bridal veil was evaluated in one study the results of which were presented earlier in this section.[rx]
- Carbohydrate wound dressings – The efficacy of Glucan dressing was evaluated in one study the results of which were presented earlier in this section.[rx]
- Negative pressure dressings – One trial compared negative pressure dressings with a conventional dressing with gauze; both dressings were used over skin grafts (receiver sites).[rx]The trial reported that the negative pressure dressing was associated with a higher percentage of graft take and shorter duration of dressing.[rx]
Complication of Wound Healing
Factors that can slow the wound healing process include
- Dead skin (necrosis) – dead skin and foreign materials interfere with the healing process.
- Infection – an open wound may develop a bacterial infection. The body fights the infection rather than healing the wound.
- Haemorrhage – persistent bleeding will keep the wound margins apart.
- Mechanical damage – for example, a person who is immobile is at risk of bedsores because of constant pressure and friction.
- Diet – poor food choices may deprive the body of the nutrients it needs to heal the wound, such as vitamin C, zinc and protein.
- Medical conditions – such as diabetes, anaemia and some vascular diseases that restrict blood flow to the area, or any disorder that hinders the immune system.
- Age – wounds tend to take longer to heal in elderly people.
- Medicines – certain drugs or treatments used in the management of some medical conditions may interfere with the body’s healing process.
- Smoking – cigarette smoking impairs healing and increases the risk of complications.
- Varicose veins – restricted blood flow and swelling can lead to skin break down and persistent ulceration.
- Dryness – wounds (such as leg ulcers) that are exposed to the air are less likely to heal. The various cells involved in healing, such as skin cells and immune cells, need a moist environment.