The skin has two layers
The skin has two layers: the epidermis and the dermis (Fig. 48-1). They are separated by a membrane, often referred to as the dermal-epidermal junction. The epidermis, or the top layer, has several layers. The stratum corneum is the thin, outermost layer of the epidermis. It consists of flattened, dead, keratinized cells. The cells originate from the innermost epidermal layer, commonly called the basal layer. Cells in the basal layer divide, proliferate, and migrate toward the epidermal surface. After they reach the stratum corneum, they flatten and die. This constant movement ensures replacement of surface cells sloughed during normal desquamation or shedding. The thin stratum corneum protects underlying cells and tissues from dehydration and prevents entrance of certain chemical agents. The stratum corneum allows evaporation of water from the skin and permits absorption of certain topical medications.
Skin-Associated Issues
� Age-related changes such as reduced skin elasticity, decreased collagen, and thinning of underlying muscle and tissues cause the older adult's skin to be easily torn in response to mechanical trauma, especially shearing forces (Wysocki, 2012).
� Concomitant medical conditions and polypharmacy, which are common in the older adult, are factors that interfere with wound healing.
� The attachment between the epidermis and dermis becomes flattened in older adults, allowing the skin to be easily torn in response to mechanical trauma (e.g., tape removal).
� Aging causes a diminished inflammatory response, resulting in slow epithelialization and wound healing (Doughty and Sparks-Defriese, 2012).
� The hypodermis decreases in size with age. Older patients have little subcutaneous padding over bony prominences; thus they are more prone to skin breakdown (Wysocki, 2012).
� An identified risk factor for the development of pressure ulcers is malnutrition
Malnutrition
Malnutrition is the condition that occurs when your body does not get enough nutrients.
The dermis
The dermis, the inner layer of the skin, provides tensile strength, mechanical support, and protection to the underlying muscles, bones, and organs. It differs from the epidermis in that it contains mostly connective tissue and few skin cells. Collagen (a tough, fibrous protein), blood vessels, and nerves are found in the dermal layer. Fibroblasts, which are responsible for collagen formation, are the only distinctive cell type within the dermis.
What happens when the skin is injured?
When the skin is injured, the epidermis functions to resurface the wound and restore the barrier against invading organisms while the dermis responds to restore the structural integrity (collagen) and the physical properties of the skin. The normal aging process alters skin characteristics and makes skin more vulnerable to damage.
Pressure Ulcers
Pressure ulcer, pressure sore, decubitus ulcer, and bedsore are terms used to describe impaired skin integrity related to unrelieved, prolonged pressure. The most current terminology is pressure ulcer (Fig. 48-2), which is consistent with the recommendations of the pressure ulcer guidelines written by the Wound, Ostomy and Continence Nurses Society (WOCN, 2010). A pressure ulcer is localized injury to the skin and other underlying tissue, usually over a body prominence, as a result of pressure or pressure in combination with shear and/or friction. A number of contributing factors are also associated with pressure ulcers; the significance of these factors is yet to be elucidated (EPUAP and NPUAP, 2009). Any patient experiencing decreased mobility, decreased sensory perception, fecal or urinary incontinence, and/or poor nutrition is at risk for pressure ulcer development.
Many factors contribute to the formation of a pressure ulcer. Pressure is the major cause. Tissues receive oxygen and nutrients and eliminate metabolic wastes via the blood. Any factor that interferes with blood flow in turn interferes with cellular metabolism and the function or life of the cells. Prolonged, intense pressure affects cellular metabolism by decreasing or obliterating blood flow, resulting in tissue ischemia and ultimately tissue death.
Pathogenesis of Pressure Ulcers
Pathogenesis of Pressure Ulcers
Pressure Intensity:
A study identified capillary closing pressure as the minimal amount of pressure required to collapse a capillary (e.g., when the pressure exceeds the normal capillary pressure range of 15 to 32 mm Hg) (Burton and Yamada, 1951). Therefo
If the pressure applied over a capillary exceeds the normal capillary pressure and the vessel is occluded for a prolonged period of time, tissue ischemia can occur. If the patient has reduced sensation and cannot respond to the discomfort of the ischemia, tissue ischemia and tissue death result.
How to evaluate areas of pressure intensity?
The clinical presentation of obstructed blood flow occurs when evaluating areas of pressure. After a period of tissue ischemia, if the pressure is relieved and the blood flow returns, the skin turns red. The effect of this redness is vasodilation (blood vessel expansion), called hyperemia (redness). Evaluate an area of hyperemia by pressing a finger over the affected area. If it blanches (turns lighter in color) and the erythema returns when you remove your finger, the hyperemia is transient and is an attempt to overcome the ischemic episode, thus called blanching hyperemia (Pieper, 2012). However, if the erythematous area does not blanch (nonblanching erythema) when you apply pressure, deep tissue damage is probable.
Blanching
Blanching occurs when the normal red tones of the light-skinned patient are absent. It does not occur in patients with darklypigmented skin. The Task Force on the Implications for Darkly Pigmented Intact Skin in the Prediction and Prevention of Pressure Ulcers (Bennett, 1995) defined darkly pigmented skin as skin that "remains unchanged (does not blanch) when pressure is applied over a bony prominence, irrespective of the patient's race or ethnicity.
Characteristics of Dark Skin with Impaired Integrity:
COLOR
TEMPERATURE
APPEARANCE
� Color remains unchanged when pressure is applied.
� If patient previously has a pressure ulcer, that area of skin may be lighter than original color.
Temperature
� Circumscribed area of intact skin may be warm to touch. As tissue changes color, intact skin feels cool to touch.
� Inflammation is detected by making comparisons to surrounding skin.
Appearance
� Edema may occur with induration and appear taut and shiny.
� Localized area of skin may be purple/blue or violet instead of red.
Characteristics of Dark Skin with Impaired Integrity:
PRESSURE DURATION
TISSUE TOLERANCE
Pressure Duration
Low pressure over a prolonged period and high-intensity pressure over a short period are two concerns related to duration of pressure. Both types of pressure cause tissue damage. Extended pressure occludes blood flow and nutrients and contributes to cell death (Pieper, 2012). Clinical implications of pressure duration include evaluating the amount of pressure (checking skin for reactive hyperemia) and determining the amount of time that a patient tolerates pressure (checking to be sure after relieving pressure that the affected area blanches).
Tissue Tolerance
The ability of tissue to endure pressure depends on the integrity of the tissue and the supporting structures. The extrinsic factors of shear, friction, and moisture affect the ability of the skin to tolerate pressure: the greater the degree to which the factors of shear, friction, and moisture are present, the more susceptible the skin will be to damage from pressure. The second factor related to tissue tolerance is the ability of the underlying skin structures (blood vessels, collagen) to assist in redistributing pressure. Systemic factors such as poor nutrition, increased aging, hydration status, and low blood pressure affect the tolerance of the tissue to externally applied pressure.
Impaired Sensory Perception
Patients with altered sensory perception for pain and pressure are more at risk for impaired skin integrity than those with normal sensation. Patients with impaired sensory perception of pain and pressure are unable to feel when a portion of their body undergoes increased, prolonged pressure or pain. Thus the patient who can't feel or sense that there is pain or pressure is at risk for the development of pressure ulcers.
Impaired Mobility
Patients unable to independently change positions are at risk for pressure ulcer development. For example, patients with spinal cord injuries have decreased or absent motor and sensory impairment and are unable to reposition off bony prominences.
Alteration in Level of Consciousness
Patients who are confused or disoriented and those who have expressive aphasia or other inability to verbalize or changing levels of consciousness are unable to protect themselves from pressure ulcer development. Patients who are confused or disoriented are sometimes able to feel pressure but are not always able to understand how to relieve it or communicate their discomfort. Patients in a coma cannot perceive pressure and are unable to move voluntarily to relieve pressure.
Shear
Shear force is the sliding movement of skin and subcutaneous tissue while the underlying muscle and bone are stationary (Bryant, 2012). For example, shear force occurs when the head of the bed is elevated and the sliding of the skeleton starts but the skin is fixed because of friction with the bed (Fig. 48-3). It also occurs when transferring a patient from bed to stretcher and the patient's skin is pulled across the bed. When shear is present, the skin and subcutaneous layers adhere to the surface of the bed, and the layers of muscle and the bones slide in the direction of body movement. The underlying tissue capillaries are stretched and angulated by the shear force. As a result, necrosis occurs deep within the tissue layers. The tissue damage occurs deep in the tissues, causing undermining of the dermis.
Friction
The force of two surfaces moving across one another such as the mechanical force exerted when skin is dragged across a coarse surface such as bed linens is called friction (WOCN, 2010). Unlike shear injuries, friction injuries affect the epidermis or top layer of the skin. The denuded skin appears red and painful and is sometimes referred to as a "sheet burn." A friction injury occurs in patients who are restless, in those who have uncontrollable movements such as spastic conditions, and in those whose skin is dragged rather than lifted from the bed surface during position changes.
Moisture
The presence and duration of moisture on the skin increases the risk of ulcer formation. Moisture reduces the resistance of the skin to other physical factors such as pressure and/or shear force. Prolonged moisture softens skin, making it more susceptible to damage. Immobilized patients who are unable to perform their own hygiene needs depend on the nurse to keep the skin dry and intact. Skin moisture originates from wound drainage, excessive perspiration, and fecal or urinary incontinence.
Classification of Pressure Ulcers
You need to assess pressure ulcers at regular intervals using systematic parameters to evaluate wound healing, plan appropriate interventions, and evaluate progress. Assessment includes depth of tissue involvement (staging), type and approximate percentage of tissue in wound bed, wound dimensions, exudate description, and condition of surrounding skin.
One method for assessment of a pressure ulcer is the use of a staging system. Staging systems for pressure ulcers are based on describing the depth of tissue destroyed. Accurate staging requires knowledge of the skin layers. A major drawback of a staging system is that you cannot stage an ulcer covered with necrotic tissue because the necrotic tissue is covering the depth of the ulcer. The necrotic tissue must be debrided or removed to expose the wound base to allow for assessment.
Pressure ulcer staging describes the pressure ulcer depth at the point of assessment. Thus, once you have staged the pressure ulcer, this stage endures even as it heals. Pressure ulcers do not progress from a stage III to a stage I; rather, a stage III ulcer demonstrating signs of healing is described as a healing stage III pressure ulcer (Pieper, 2012). The EPUAP and NPUAP have developed clinical practice guidelines for pressure ulcers and have advanced the following classification/staging system
Classification of Pressure Ulcers:
Stage I: Nonblanchable Redness of Intact Skin
ntact skin presents with nonblanchable erythema of a localized area usually over a bony prominence. Discoloration of the skin, warmth, edema, hardness, or pain may also be present. Darkly pigmented skin may not have visible blanching.
Further description: The area may be painful, firm, soft, warmer, or cooler than adjacent tissue. Stage I may be difficult to detect in individuals with dark skin tones. It may indicate "at-risk" persons
Classification of Pressure Ulcers:
Stage II: Partial-thickness Skin Loss or Blister
A partial-thickness loss of dermis presents as a shallow open ulcer with a red-pink wound bed without slough. It may also present as an intact or open/ruptured serum-filled or serosangineous filled blister.
Further description: Stage II presents as a shiny or dry shallow ulcer without slough or bruising. This stage should not be used to describe skin tears, tape burns, incontinence-associated dermatitis, maceration, or excoriation
Classification of Pressure Ulcers:
Stage III: Full-thickness Skin Loss (Fat Visible)
A stage III ulcer is a full-thickness tissue loss. Subcutaneous fat may be visible; but bone, tendon, or muscle is not exposed. Some slough may be present. It may include undermining and tunneling.
Further description: The depth of a stage III pressure ulcer varies by anatomical location. The bridge of the nose, ear, occiput, and malleolus do not have (adipose) subcutaneous tissue; and stage III ulcers can be shallow. In contrast, areas of significant adiposity can develop extremely deep stage III pressure ulcers. Bone/tendon is not visible or directly palpable
Classification of Pressure Ulcers:
Stage IV: Full-thickness Tissue Loss (Muscle/Bone Visible)
A stage IV ulcer is a full-thickness tissue loss with exposed bone, tendon, or muscle. Slough or eschar may be present. It often includes undermining and tunneling.
Further description: The depth of a stage IV pressure ulcer varies by anatomical location. The bridge of the nose, ear, occiput, and malleolus do not have (adipose) subcutaneous tissue; and these ulcers can be shallow. Stage IV ulcers can extend into muscle and/or supporting structures (e.g., fascia, tendon, or joint capsule), making osteomyelitis or osteitis likely to occur. Exposed bone/muscle is visible or directly palpable
Classification of Pressure Ulcers:A stage IV ulcer is a full-thickness tissue loss with exposed bone, tendon, or muscle. Slough or eschar may be present. It often includes undermining and tunneling.
Further description: The depth of a stage IV pressure ul
The EPUAP and the NPUAP (2009) developed a definition for an ulcer in which the base of the wound cannot be visualized and a definition of tissue injury in which the depth of injury is unknown. An unstageable ulcer is a full-thickness tissue loss in which actual depth of the ulcer is completely obscured by slough (yellow, tan, gray, green, or brown) and/or eschar (tan, brown, or black) in the wound bed (Fig. 48-4, E).
Further description: Until enough slough and/or eschar are removed to expose the base of the wound, the true depth cannot be determined; but it is either a stage III or IV. Stable (dry, adherent, intact without erythema or fluctuance) eschar on the heels serves as "the natural (biological) cover of the body" and should not be removed.
Classification of Pressure Ulcers:
Suspected Deep-Tissue Injury�Depth Unknown
Suspected deep-tissue injury is a purple or maroon localized area of discolored intact skin or blood-filled blister caused by damage of underlying soft tissue from pressure and/or shear (Fig. 48-4, F).
Further description: The area may be preceded by tissue that is painful, firm, mushy, boggy, warmer, or cooler than adjacent tissue. Deep-tissue injury may be difficult to detect in individuals with dark skin tones. Evolution may include a thin blister over a dark wound bed. The wound may further evolve and become covered by thin eschar. Evolution may be rapid, exposing additional layers of tissue even with treatment.
In addition, Bennett (1995) suggests that, when assessing patients with darkly pigmented skin, proper lighting is important to accurately assess the skin (see Box 48-2). Either natural light or a halogen light is recommended. This prevents the blue tones that fluorescent light sources produce on darkly pigmented skin, which interferes with accurate assessment.
You need to assess the type of tissue in the wound base; this information is used to plan appropriate interventions. The assessment of tissue type includes the amount (percentage) and appearance (color) of viable and nonviable tissue.
Granulation tissue is red, moist tissue composed of new blood vessels, the presence of which indicates progression toward healing. Soft yellow or white tissue is characteristic of slough (stringy substance attached to wound bed), and it must be removed by a skilled clinician before the wound is able to heal. Black or brown necrotic tissue is eschar, which also needs to be removed before healing can proceed.
The measurement of the size of the wound provides overall changes in size, which is an indicator for wound healing progress (Nix, 2012). Use disposable wound-measuring devices to obtain measurement of width and length.
Wound Classification:Acute
Wound that proceeds through an orderly and timely reparative process that results in sustained restoration of anatomical and functional integrity
Caused by Trauma, a surgical incision
Wounds are usually easily cleaned and repaired. Wound edges are clean and intact.
Wound Classification:Chronic
Wound that fails to proceed through an orderly and timely process to produce anatomical and functional integrity
Caused byVascular compromise, chronic inflammation, or repetitive insults to tissue
Continued exposure to insult impedes wound healing.
Healing Process:Primary Intention
Wound that is closed
Surgical incision, wound that is sutured or stapled
Healing occurs by epithelialization; heals quickly with minimal scar formation.
Healing Process:Secondary Intention
Wound edges not approximated
Pressure ulcers, surgical wounds that have tissue loss
Wound heals by granulation tissue formation, wound contraction, and epithelialization.
Healing Process:Tertiary Intention
Wound left open for several days, then wound edges are approximated (see Fig. 48-4,C)
Wounds that are contaminated and require observation for signs of inflammation
Closure of wound is delayed until risk of infection is resolved
Wound exudate should describe the amount...
Wound exudate should describe the amount, color, consistency, and odor of wound drainage and is part of the wound assessment. Excessive exudate indicates the presence of infection. Finally, assess the condition of the skin surrounding the wound for redness, warmth, maceration, or edema (swelling). The presence of any of these factors on the skin surrounding the wound indicates wound deterioration.
The skin around the wound (periwound) should be assessed. Examine the periwound area for redness, warmth, and signs of maceration and palpate the area for signs of pain or induration.
Wound Classifications
A wound is a disruption of the integrity and function of tissues in the body (Baharestani, 2008). It is imperative for the nurse to know that all wounds are not created equal. Understanding the etiology of a wound is important because the treatment for it varies, depending on the underlying disease process.
There are many ways to classify wounds. Wound classification systems describe the status of skin integrity, cause of the wound, severity or extent of tissue injury or damage, cleanliness of the wound (Table 48-1), or descriptive qualities of the wound tissue such as color (Fig. 48-5). Wound classifications enable a nurse to understand the risks associated with a wound and implications for healing.
Process of Wound Healing
Wound healing involves integrated physiological processes. The tissue layers involved and their capacity for regeneration determine the mechanism for repair for any wound
There are two types of wounds: those with loss of tissue and those without.
There are two types of wounds: those with loss of tissue and those without. A clean surgical incision is an example of a wound with little tissue loss. The surgical incision heals by primary intention . The skin edges are approximated, or closed, and the risk of infection is low. Healing occurs quickly, with minimal scar formation, as long as infection and secondary breakdown are prevented . In contrast, a wound involving loss of tissue such as a burn, pressure ulcer, or severe laceration heals by secondary intention. The wound is left open until it becomes filled by scar tissue. It takes longer for a wound to heal by secondary intention; thus the chance of infection is greater. If scarring from secondary intention is severe, loss of tissue function is often permanent
Wound Repair
Partial-thickness wounds are shallow wounds involving loss of the epidermis (top layer) and possibly partial loss of the dermis. These wounds heal by regeneration because epidermis regenerates. An example of this is the repair of a clean surgical wound or an abrasion. Full-thickness wounds extending into the dermis (involving both layers of tissue) heal by scar formation because deeper structures do not regenerate. Pressure ulcers are an example of full-thickness wounds.
Partial-Thickness Wound Repair
Three components are involved in the healing process of a partial-thickness wound: inflammatory response, epithelial proliferation (reproduction) and migration, and reestablishment of the epidermal layers.
Tissue trauma causes the inflammatory response, which in turn causes redness and swelling to the area with a moderate amount of serous exudate. This response is generally limited to the first 24 hours after wounding. The epithelial cells begin to regenerate, providing new cells to replace the lost cells. The epithelial proliferation and migration start at both the wound edges and the epidermal cells lining the epidermal appendages, allowing for quick resurfacing. Epithelial cells begin to migrate across the wound bed soon after the wound occurs. A wound left open to air can resurface within 6 to 7 days, whereas one that is kept moist can resurface in 4 days. The difference in the healing rate is related to the fact that epidermal cells only migrate across a moist surface. In a dry wound the cells migrate down into a moist level before migration can occur. New epithelium is only a few cells thick and must undergo reestablishment of the epidermal layers. The cells slowly reestablish normal thickness and appear as dry, pink tissue.
Full-Thickness Wound Repair:
The four phases involved in the healing process of a full-thickness wound are hemostasis, inflammatory, proliferative, and remodeling.
Complications of Wound Healing:Hemorrhage
Hemorrhage, or bleeding from a wound site, is normal during and immediately after initial trauma. Hemostasis occurs within several minutes unless large blood vessels are involved or the patient has poor clotting function. Hemorrhage occurring after hemostasis indicates a slipped surgical suture, a dislodged clot, infection, or erosion of a blood vessel by a foreign object (e.g., a drain). Hemorrhage occurs externally or internally. For example, if a surgical suture slips from a blood vessel, bleeding occurs internally within the tissues, and there are no visible signs of blood unless a surgical drain is present. A surgical drain may be inserted into tissues beneath a wound to remove fluid that collects in underlying tissues.
You detect internal bleeding by looking for distention or swelling of the affected body part, a change in the type and amount of drainage from a surgical drain, or signs of hypovolemic shock. A hematoma is a localized collection of blood underneath the tissues. It appears as a swelling, change in color, sensation, or warmth or mass that often takes on a bluish discoloration. A hematoma near a major artery or vein is dangerous because pressure from the expanding hematoma obstructs blood flow.
External hemorrhaging is obvious. The nurse observes dressings covering the wound for bloody drainage. If bleeding is extensive, the dressing soon becomes saturated, and frequently blood drains from under the dressing and pools beneath the patient. Observe all wounds closely, particularly surgical wounds, in which the risk of hemorrhage is great during the first 24 to 48 hours after surgery or injury.
Complications of Wound Healing:Infection
Wound infection is the second most common health care-associated infection (nosocomial) (see Chapter 28). According to the Centers for Disease Control and Prevention (CDC) (2001), a wound is infected if purulent material drains from it, even if a culture is not taken or has negative results. A sample of drainage from an infected wound does not always reveal bacteria because of poor culture technique or administration of antibiotics. Positive culture findings do not always indicate an infection because many wounds contain colonies of noninfective resident bacteria. In fact, all chronic dermal wounds are considered contaminated with bacteria. What differentiates contaminated wounds from infected wounds is the amount of bacteria present. It is generally agreed that wounds with more than 100,000 (105) organisms per gram of tissue are infected (Stotts, 2012b). The chances of wound infection are greater when the wound contains dead or necrotic tissue, there are foreign bodies in or near the wound, and the blood supply and local tissue defenses are reduced. Bacterial wound infection inhibits wound healing.
Some contaminated or traumatic wounds show signs of infection early, within 2 to 3 days.
Some contaminated or traumatic wounds show signs of infection early, within 2 to 3 days. A surgical wound infection usually does not develop until the fourth or fifth postoperative day. The patient has a fever, tenderness and pain at the wound site, and an elevated white blood cell count. The edges of the wound appear inflamed. If drainage is present, it is odorous and purulent, which causes a yellow, green, or brown color, depending on the causative organism
Dehiscence
When a wound fails to heal properly, the layers of skin and tissue separate. This most commonly occurs before collagen formation (3 to 11 days after injury). Dehiscence is the partial or total separation of wound layers. A patient who is at risk for poor wound healing (e.g., poor nutritional status, infection, or obesity) is at risk for dehiscence. However, obese patients have a higher risk because of the constant strain placed on their wounds and the poor healing qualities of fat tissue (Camden, 2012). Dehiscence frequently involves abdominal surgical wounds and occurs after a sudden strain such as coughing, vomiting, or sitting up in bed. Patients often report feeling as though something has given way. When there is an increase in serosanguineous drainage from a wound, be alert for the potential for dehiscence. A strategy to prevent dehiscence is to place a folded thin blanket or pillow over an abdominal wound when the patient is coughing. This provides a splint to the area, supporting the healing tissue when coughing increases the intraabdominal pressure.
Evisceration
With total separation of wound layers, evisceration (protrusion of visceral organs through a wound opening) occurs. The condition is an emergency that requires surgical repair. When evisceration occurs, the nurse places sterile towels soaked in sterile saline over the extruding tissues to reduce chances of bacterial invasion and drying of the tissues. If the organs protrude through the wound, blood supply to the tissues is compromised. The presence of an evisceration is a surgical emergency. Immediately contact the surgical team, do not allow the patient anything by mouth (NPO), observe him or her for signs and symptoms of shock, and prepare him or her for emergency surgery.
Nursing Knowledge Base:
Prediction and Prevention of Pressure Ulcers
A major aspect of nursing care is the maintenance of skin integrity. Consistent, planned skin care interventions are critical to ensuring high-quality care. Nurses constantly observe their patients' skin for breaks or impaired skin integrity. Impaired skin integrity occurs from prolonged pressure, irritation of the skin, and/or immobility, leading to the development of pressure ulcers. A pressure ulcer is a localized injury to the skin and/or underlying tissue, usually over a bony prominence, as a result of pressure or pressure in combination with shear and/or friction
Nursing Knowledge Base:Risk Assessment
Several instruments are available for assessing patients who are at risk for developing a pressure ulcer. By identifying at-risk patients, you are able to put interventions into place for the at-risk patient and spare patients with little risk for pressure ulcer development the unnecessary and sometimes costly preventive treatment. Prevention and treatment of pressure ulcers are major nursing priorities. The incidence of pressure ulcers in a facility or agency is an important indicator of quality of care. Evidence exists that a program of prevention guided by risk assessment simultaneously reduces the institutional incidence of pressure ulcers by as much as 60% and brings down the costs of prevention at the same time . Several risk-assessment scales developed by nurses enable systematic risk assessment of patients. The Braden Scale, a widely used risk-assessment tool, is in the WOCN guidelines (2010) as being a valid tool to use for pressure ulcer risk assessment. The Braden Scale was developed based on risk factors in a nursing home population and is composed of six subscales: sensory perception, moisture, activity, mobility, nutrition, and friction/shear. The total score ranges from 6 to 23; a lower total score indicates a higher risk for pressure ulcer development (Braden and Bergstrom, 1989). The cutoff score for onset of pressure ulcer risk with the Braden Scale in the general adult population is 18 (Ayello and Braden, 2002). It is highly reliable when used to identify patients at greatest risk for pressure ulcers (Bergstrom et al., 1987; Braden and Bergstrom, 1994). The Braden Scale is the most commonly used assessment scale for pressure ulcer risk.
Nursing Knowledge Base:
Prevention
Preventing pressure ulcers is a priority in caring for patients and is not limited to patients with restrictions in mobility. Impaired skin integrity is not usually a problem in healthy, immobilized individuals but is a serious and potentially devastating problem in ill or debilitated patients
Role of Selected Nutrients in Wound Healing
Calories
Fuel for cell energy "Protein protection"
35-40 kcal/kg/day or enough to maintain positive nitrogen balance
Protein
Fibroplasia, angiogenesis, collagen formation and wound remodeling, immune function
1-1.5 g/kg/day or enough to maintain positive nitrogen balance
Poultry, fish, eggs, beef
Vitamin C (ascorbic acid)
Collagen synthesis, capillary wall integrity, fibroblast function, immunological function, antioxidant
100-1000 mg/day
Need long time to develop clinical scurvy from vitamin C deficiency
Low toxicity
Citrus fruits, tomatoes, potatoes, fortified fruit juices
Vitamin A
Epithelialization, wound closure, inflammatory response, angiogenesis, collagen formation
1600-2000 retinol equivalents per day
Supplement if deficient
20,000 units � 10 days
Green leafy vegetables (spinach), broccoli, carrots, sweet potatoes, liver
Can reverse steroid effects on skin and delayed healing
Vitamin E
No known role in wound healing, antioxidant
None
Fish, oysters, liver, dark meat, eggs, legumes Zinc
Collagen formation, protein synthesis, cell membrane and host defenses
15-30 mg
Correct deficiencies
No improvement in wound healing with supplementation unless zinc deficient
Use with caution�large doses can be toxic
May inhibit copper metabolism and impair immune function
Vegetables, meats, legumes
Fluid
Essential fluid environment for all cell function
30-35 mL/kg/day
Increase by another 10-15 mL/kg if patient is on an air-fluidized bed
Use noncaffeine, nonalcoholic fluids without sugar
Water is best�6-8 glasses/day
What is ischemia?
Ischemia is any reduction in blood flow resulting in decreased oxygen and nutrient supplies to a tissue. Ischemia may be reversible, in which case the affected tissue will recover if blood flow is restored, or it may be irreversible, resulting in tissue death. Ischemia can also be acute, due to a sudden reduction in blood flow, or chronic, due to slowly decreasing blood flow.