Wound Care/Pressure Injury Management

Black/brown wounds/eschar

-Black or brown tissue is eschar, which represents full-thickness tissue destruction. Black is used to describe necrotic tissue or desiccated tissue such as tendon. It is also related to gangrenous lesions secondary to peripheral vascular disease. -If the goal for a wound covered with eschar is debridement, sharp debridement is used to quickly remove the tissue, chemical debridement is used to soften the tissue for removal, or a moist dressing is also considered to loosen the tissue. The method of debridement depends on the overall goal for the patient.

Red wounds/granulation

-Red tissue represents the presence of granulation tissue. The red color is the result of an increasing amount of new blood vessels in the wound and is considered healthy. -The goal in management of a red granulated wound is to select a dressing that maintains a clean and moist wound environment and minimizes damage to healing tissue.

Performing a Wound Assessment

-Wound assessment provides the baseline for planning and evaluating the wound care plan. Normal wound healing occurs in an organized fashion, and evaluating the wound status provides an ongoing assessment of wound healing and helps to determine wound treatments. The frequency of wound assessment depends on the patient's overall condition, policy of the health care setting, type of dressings used, and overall patient goals (Nix, 2016). Acute care settings generally require wound assessment daily or with each dressing change. Long-term care facilities may require an initial admission wound assessment and weekly assessment for chronic wounds. Check agency policy for frequency of wound assessment and specific wound assessment tool. Digital photography may be a tool used for both assessment and documentation of wounds. Routine wound assessments provide valuable information regarding the status of a wound. For example, is wound healing progressing as expected, or is it delayed? Is there new drainage (color and volume)? Wound size may increase in a wound with necrotic tissue. Removal of the necrotic tissue may result in a larger wound and is an expected finding. An increase in the amount and consistency of the drainage and new presence of odor may indicate a wound infection; and a wound culture is often necessary to support appropriate antibiotics. The following parameters are included in a wound assessment: • Location: Note the anatomical position of the wound. • Type of wound: If possible, note the etiology of the wound (i.e., surgical, pressure, trauma). • Extent of tissue involvement: Full-thickness wound involves both the dermis and epidermis. Partial-thickness wound involves only the epidermal layer. If it is a pressure injury, use the staging system of the European Pressure Ulcer Advisory Panel (EPUAP) National Pressure Injury Advisory Panel (NPIAP), and Pan Pacific Pressure Injury Alliance (PPPIA) (2019a); see Chapter 40). • Type and percentage of tissue in wound base: Describe the type of tissue (i.e., granulation, slough, eschar) and the approximate amount. • Wound size: Follow agency policy to measure wound dimensions, which include width, length, and depth. • Wound exudate: Describe the amount, color, and consistency. Serous drainage is clear like plasma; sanguineous or bright red drainage indicates fresh bleeding; serosanguineous drainage is pink; and purulent drainage is thick and yellow, pale green, or white. • Presence of odor: Note the presence or absence of odor, which may indicate infection. • Periwound area: Assess the color, temperature, and integrity of the skin. • Pain: Use a validated pain assessment scale to evaluate pain. Steps: 1. Identify patient using at least two identifiers (e.g., name and birthday or name and medical record number) according to agency policy (TJC, 2021). 2. Examine the medical record for findings from the last wound assessment to use as a comparison for this wound assessment. Review the record to determine the etiology of the wound. 3. Determine agency-approved wound assessment tool and review the frequency of assessment. Examine the last wound assessment to use as comparison for this assessment. 4. Assess patient's/family caregiver's health literacy. 5. Assess patient's knowledge and prior experience with wound assessment. 6. Assess comfort level or pain on a scale of 0 to 10 and identify symptoms of anxiety. Offer pain medication if indicated. 7. Perform hand hygiene. Close room door or bed curtains and position patient. a. Position comfortably to permit observation of wound in well-lighted room. b. Expose only the area of the wound. 8. Explain procedure of wound assessment to patient. 9. Form a cuff on waterproof biohazard bag and place near bed. 10. Apply clean gloves and remove soiled dressings; remove gauze one layer at a time. 11. Examine dressings for quality of drainage (color, consistency), presence or absence of odor, and quantity of drainage (note if dressings were saturated, slightly moist, or had no drainage). Discard dressings in waterproof biohazard bag. Remove and discard gloves. 12. Perform hand hygiene and apply clean gloves. 13. Inspect wound and determine type of wound healing (e.g., primary or secondary intention). 14. Use agency-approved assessment tool and assess the following: a. Wound healing by primary intention (surgical wound): (1) Assess anatomical location of wound on body. (2) Note if incisional wound margins are approximated or closed together. The wound edges should be together with no gaps. (3) Observe for presence of drainage. A closed incision should not have any drainage. (4) Look for evidence of infection (presence of erythema, odor, or wound drainage). (5) Lightly palpate along incision to feel a healing ridge (see Fig. 39.2). The ridge will appear as an accumulation of new tissue presenting as firmness beneath the skin, extending to about 1 cm (½ inch) on each side of the wound between 5 and 9 days after the incision was created. This is an expected positive sign (Doughty and Sparks-Defriese, 2016). b. Wound healing by secondary intention (e.g., pressure injury or contaminated surgical or traumatic wound): (1) Assess anatomical location of wound. (2) Assess wound dimensions: Measure size of wound (including length, width, and depth) using a centimeter measuring guide. Measure length by placing the disposable measuring guide over wound at the point of greatest length (or head to foot). Measure width from side to side (Nix, 2016) (see illustration). Measure depth by inserting cotton-tipped applicator in area of greatest depth and placing a mark on applicator at skin level; use measuring guide to determine depth. Discard measuring guide and cotton-tipped applicator in a biohazard bag. (3) Assess for undermining: Use cotton-tipped applicator to gently probe wound edges. If undermining is present, measure depth and note location using the face of a clock as a guide. The 12-o'clock position (top of wound) would be the head of patient, and the 6-o'clock position would be the bottom of the wound toward patient's feet. Document the number of centimeters that area extends from wound edge underneath intact skin. (4) Assess extent of tissue loss: If wound is a pressure injury, determine the deepest viable tissue layer in wound bed and determine stage. If necrotic tissue does not allow visualization of base of wound, the stage cannot be determined. If it is a pressure injury, use the staging system of the National Pressure Injury Advisory Panel (EPUAP/NPIAP/PPPIA, 2019a). (5) Observe tissue type, including percentage of granulation, slough, and necrotic tissue. (6) Note presence of exudate: amount, color, consistency, and odor. Indicate amount of exudate by using part of dressing saturated (completely or partially saturated or in terms of quantity—e.g., scant, moderate, or copious). (7) Determine if wound edges are rounded toward wound bed; this may be an indication of delayed wound healing. Describe presence of epithelialization at wound edges (if present) because this indicates movement toward healing. 15. Inspect the periwound skin, including color, texture, and temperature; and describe skin integrity (e.g., open macerated areas, blistering). Periwound assessment provides clues about the effectiveness of wound treatment and possible wound extension (Nix, 2016). 16. Apply dressings per order. Place time, date, and initials on new dressing. 17. Reassess patient's pain and level of comfort, including pain at wound site, using a scale of 0 to 10, after dressing is applied. 18. Discard biohazard bag and soiled supplies per agency policy. Remove and dispose of gloves. Perform hand hygiene. 19. Record wound assessment findings and compare assessment with previous wound assessments to monitor wound healing. 20. Report any serious complication such as new bleeding or signs of dehiscence to health care provider.

negative pressure wound therapy steps

1. Cuff top of disposable waterproof biohazard bag and place within reach of work area. 2. Perform hand hygiene and apply clean gloves. If risk for spray exists, apply protective gown, goggles, and mask. 3. Follow manufacturer directions for removal and replacement because each NPWT unit varies slightly with approach. Turn off NPWT unit by pushing therapy on/off button. a. Keeping tube connectors attached to NPWT unit, raise tubing connectors; disconnect tubes from one another and drain fluids into drainage collector. Prevents backflow of any drainage in tubing back into wound. b. Before draining, tighten clamp on canister tube and disconnect canister and dressing tubing at connection points. 4. Remove transparent film by gently stretching, and slowly pull away from skin. 5. Remove old dressing one layer at a time and discard in bag. Observe drainage on dressing. Use caution to avoid tension on any drains that are present near the wound or surrounding area. Remove and dispose of gloves. 6. Perform hand hygiene and conduct a wound assessment. Observe surface area and tissue type, color, odor, and drainage within wound. Measure length, width, and depth of wound as ordered (see Procedural Guideline 39.1). 7. Remove and discard gloves in biohazard bag. Prevent patient from seeing old dressing because sight of wound drainage may be upsetting. 8. Clean wound per order or recommendations of wound care specialist. a. Perform hand hygiene. Apply sterile or clean gloves, depending on agency policy and wound status. b. If ordered, irrigate wound with normal saline or other solution ordered by health care provider (see Skill 39.1). Gently blot periwound with gauze to dry thoroughly. 9. Apply skin protectant, barrier film, solid skin barrier sheet, or hydrocolloid dressing to periwound skin. 10. Fill any uneven skin surfaces (e.g., creases, scars, and skinfolds) with skin-barrier product (e.g., paste, strip). 11. Remove and discard gloves. Perform hand hygiene. 12. Depending on type of wound, apply sterile or new clean gloves (see agency policy). 13. Apply NPWT. a. Prepare NPWT filler dressing. Consult with wound care expert for appropriate type. (1) Measure clean wound and select appropriate-size dressing. (2) Using sterile scissors, cut filler dressing foam to wound size, making sure to fit exact size and shape of wound, including tunnels and undermined areas. b. Place filler dressing in wound following manufacturer instructions. Be sure that filler dressing is in contact with entire wound base, margins, and tunneled and undermined areas. Count number of filler dressings and document in patient's chart. c. Place suction device per manufacturer instructions. d. Apply NPWT transparent dressing over foam wound dressing. (1) Trim dressing to cover wound and dressing so it will extend onto periwound skin approximately 2.5 to 5 cm (1-2 inches). (2) Apply transparent dressing, keeping it wrinkle-free (see illustration). (3) Secure tubing to transparent film, aligning drainage holes to ensure occlusive seal. Do not apply tension. Excessive tension may compress foam dressing and impede wound healing. It also produces shear force on periwound area (Netsch, 2016). (4) Secure tubing several centimeters away from dressing, avoiding pressure points. Drainage tubes over bony pressure prominences can cause medical device-related pressure injuries (Netsch et al., 2016; Netsch, 2016; Pittman et al., 2015). 14. After wound is completely covered, connect tubing from dressing to tubing from canister and NPWT unit. Then set NPWT system to ordered suction level. Intermittent or continuous negative pressure varies from 75 mm Hg to 125 mm Hg, depending on the device and the characteristics of the wound (Netsch et al., 2016; WOCN, 2016). a. Remove canister from sterile packing and push unit until you hear click. NOTE: An alarm sounds if canister is not properly engaged. b. Connect dressing tubing to canister tubing. Make sure that both clamps are open. c. Place on level surface or hang from foot of bed. NOTE: Unit alarms and deactivates therapy if it is tilted beyond 45 degrees. d. Press power button (commonly this is a green-lit button) and set pressure as ordered. 15. Remove and dispose of gloves. Perform hand hygiene. Reduces transmission of microorganisms. 16. Inspect NPWT system. a. Verify that the system is on. NOTE: This is different for each type of NPWT unit. For example, on some units the display screen shows "Therapy On." Check agency policy and procedure for specific information. b. Verify that all clamps are open and all tubing is patent. c. Examine system to be sure that seal is intact and therapy is working. d. If a leak is present, use strips of transparent film to patch areas around edges of wound. 17. Record initials, date, and time on new dressing. Provides reference for next dressing change. 18. Dispose of sharps (scissors) in designated sharps disposal bin, remove gloves, and perform hand hygiene. 19. Help patient to comfortable position. Patients may ambulate with NPWT. 20. Raise side rails (as appropriate) and lower bed to lowest position. 21. Be sure nurse call system is in an accessible location within patient's reach. EVALUATION 1. Inspect condition of wound and wound bed on an ongoing basis; note drainage and odor. 2. Ask patient to rate pain using scale of 0 to 10. 3. Verify airtight dressing seal and correct negative-pressure setting. 4. Measure wound drainage output in canister on regular basis.

Risk assessment, skin assessment, and prevention strategies

ASSESSMENT 1. Identify patient using at least two identifiers (e.g., name and birthday or name and medical record number), according to agency policy. 2. Review patient's electronic health record (EHR), including health provider's orders and nurses' notes, to assess patient's risk for pressure injury formation: a. Paralysis or immobilization caused by restrictive devices b. Presence of medical device such as nasogastric (NG) tube, oxygen equipment, artificial airways, drainage tubing, or mechanical devices (Doughty and McNichols, 2016; TJC, 2018) (1) If not medically contraindicated, remove medical device to observe and palpate skin and tissues under and around each medical device. c. Sensory loss (e.g., hemiplegia, spinal cord injury) d. Circulatory disorders (e.g., peripheral vascular diseases, vascular changes from diabetes mellitus, neuropathy) e. Fever f. Anemia g. Malnutrition h. Fecal or urinary incontinence i. Heavy sedation and anesthesia j. Age k. Dehydration l. Edema m. Existing pressure injuries n. History of pressure injury 3. Select agency-approved risk assessment tool such as the Braden Scale or Norton Scale. Perform risk assessment when patient enters health care setting and repeat on regularly scheduled basis or when there is significant change in patient's condition (WOCN, 2016). 4. Obtain risk score (see Tables 40.1 and 40.2) and evaluate its meaning based on patient's unique characteristics. When using the Braden scale there are risk scores identified for specific patient populations: intensive care patients ≤14; older adults ≤14 (Alderden et al., 2017). 5. Assess patient/family caregiver's health literacy. 6. Close room or pull curtains around bed. 7. Perform hand hygiene. Assess condition of patient's skin over regions of pressure (see Fig. 40.1). Apply clean gloves as needed with open and/or draining wounds. a. Inspect for skin discoloration (see Box 40.2 for patients with darkly pigmented skin) and tissue consistency (firm or boggy feel) and/or palpate for abnormal sensations (Nix, 2016). b. Palpate discolored area on skin and under and around medical devices, release your fingertip, and look for blanching. If on palpation an area of redness blanches (lightens in color), this indicates normal reactive hyperemia; tissue is not at risk for the development of an injury. c. Inspect for pallor and mottling. d. Inspect for absence of superficial skin layers. e. Inspect for changes in skin temperature, edema, and tissue consistency, especially in individuals with darkly pigmented skin (EPAUP, NPIAP, PPPIA, 2019a, 2019b). f. Inspect for wound drainage 8. Assess skin and tissue around and beneath medical devices at least twice daily for areas of potential pressure injury resulting from medical devices (Black et al., 2015; EPUAP, NPIAP, PPPIA, 2019a) (Table 40.3). a. Nares: NG tube, oxygen cannula b. Ears: oxygen cannula, pillow c. Tongue and lips: oral airway, endotracheal (ET) tube d. Forehead: pulse oximetry device e. Drainage or other tubing f. Indwelling urethral (Foley) catheter g. Orthopedic and positioning devices such as casts, neck collars, splints h. Compression stockings i. Immobilization device and restraints 9. Remove and dispose of gloves and perform hand hygiene. 10. Observe patient for preferred positions when in bed or chair. 11. Observe ability of patient to initiate and help with position changes. 12. Assess knowledge and experience of patient with pressure injury prevention techniques. 13. Assess patient's goals or preferences for how repositioning will be performed or what the patient expects. IMPLEMENTATION 1. Implement prevention guidelines adapted from WOCN Society Guideline for Prevention and Management of Pressure Ulcers (2016). Reduces patient's risk for developing pressure injury. 2. Perform hand hygiene and apply clean gloves. Reduces transmission of microorganisms. 3. Following initial assessment, continue to inspect skin at least once a day. a. Observe patient's skin; pay particular attention to bony prominences and areas around and under medical devices and tubes. If you find reddened area, gently press area with gloved finger to check for blanching. If area does not blanch, suspect tissue injury and recheck in 1 hour. Any discoloration may vary from pink to deep red. b. If patient has darkly pigmented skin, look for color changes that differ from his or her normal skin color. Darkly pigmented skin may not blanch. A change in color may occur at the site of pressure; this change in color differs from patient's usual skin color (EPUAP, NPIAP, PPPIA, 2019a, 2019b) (see Box 40.2). 4. Each shift check all treatment and assistive devices (catheters, feeding tubes, casts, braces) for potential pressure points (see Table 40.3). a. Verify that device is correctly sized, positioned, and secured. b. Consider shielding underlying at-risk skin with protective dressing (silicone, hydrocolloid). 5. Remove and dispose of gloves; perform hand hygiene. 6. Review patient's pressure injury risk assessment score. 7. If immobility, inactivity, or poor sensory perception is a risk factor(s) for patient, consider one of the following interventions (WOCN, 2016): a. Reposition patient on schedule basis and frequently assess individual's skin condition to help identify early signs of pressure damage. If skin changes occur, reevaluate the plan. b. When patient is in side-lying position in bed, use 30-degree lateral position (see illustration). Avoid 90-degree lateral position. c. Place patient (when lying in bed) on pressure-redistribution surface. d. Place patient (when in chair) on pressure-redistribution device and shift points under pressure at least every hour (WOCN, 2016). 8. If friction and shear are identified as risk factors, consider the following interventions: a. Use safe patient handling guidelines to reposition patient (see Chapter 11). For example, use slide board to transfer patient from bed to stretcher. b. Ensure that heels are free from bed surface by using a pillow under calves to elevate heels or use a heel-suspension device; knees should be in 5- to 10-degree flexion (Bååth et al., 2016; WCON, 2016). c. Maintain head of the bed at 30 degrees or lower or at the lowest degree of elevation consistent with patient's condition (do not lower HOB if patient is at risk for aspiration) (WOCN, 2016). 9. If patient receives low score on moisture subscale, consider one of the following interventions: a. Apply clean gloves. Clean and dry the skin as soon as possible after each incontinent episode (WOCN, 2016). Apply moisture barrier ointment to perineum and surrounding skin after each incontinent episode. b. If skin is denuded, use protective barrier paste after each incontinent episode. c. If moisture source is from wound drainage, consider frequent dressing changes, skin protection with protective barriers, or collection devices. 10. If friction and shear are risk factors and patient is chair bound: a. Tilt patient's chair seat to prevent sliding forward, and support arms, legs, and feet to maintain proper posture (EPUAP, NPIAP, PPPIA, 2019a). b. Limit amount of time patient spends in a chair without pressure relief (EPUAP, NPIAP, PPPIA, 2019a). c. For patients who can reposition themselves while sitting, encourage pressure relief every 15 minutes using chair push-ups, forward lean, or side to side (WOCN, 2016). 11. Educate patient and family regarding specific pressure injury risk factors and prevention. 12. Remove and dispose of gloves, perform hand hygiene. 13. Help patient to a comfortable position. 14. Raise side rails (as appropriate) and lower bed to lowest position. 15. Be sure nurse call system is in an accessible location within patient's reach.

Braden Scale for Predicting Pressure Ulcer Risk *

Sensory Perception: Ability to respond meaningfully to pressure-related discomfort 1. Completely limited: Unresponsive (does not moan, flinch, or grasp) to painful stimuli because of diminished level of consciousness or sedation Or: Limited ability to feel pain over most of body 2. Very limited: Responds only to painful stimuli Cannot communicate discomfort except by moaning or restlessness Or: Has a sensory impairment that limits the ability to feel pain or discomfort over half of body 3. Slightly limited: Responds to verbal commands but cannot always communicate discomfort or need to be turned Or: Has some sensory impairment, which limits ability to feel pain or discomfort in one or two extremities 4. No impairment: Responds to verbal commands Has no sensory deficit that would limit ability to feel or voice pain or discomfort Moisture: Degree to which skin is exposed to moisture 1. Constantly moist: Skin kept moist almost constantly by factors such as perspiration and urine 2. Dampness detected every time patient is moved or turned 2. Very moist: Skin often but not always moist Linen must be changed at least once a shift 3. Occasionally moist: Skin occasionally moist, requiring extra linen change approximately once a day 4. Rarely moist: Skin usually dry; linen requires changing only at routine intervals Activity Degree of physical activity 1. Bedfast: Confined to bed 2. Chairfast: Ability to walk severely limited or nonexistent Cannot bear own weight and/or must be helped into chair or wheelchair 3. Walks occasionally: Goes during day but for short distances with or without help Spends most of each shift in bed or chair 4. Walks frequently: Walks outside room at least twice a day and inside room at least once every 2 hours during waking hours Mobility Ability to change and control body position 1. Completely immobile: Does not make even slight changes in body or extremity position without help 2. Very limited: Makes occasional slight changes in body or extremity position but unable to make frequent or significant changes independently 3. Slightly limited: Makes frequent, although slight, changes in body or extremity position independently 4. No limitations: Makes major and frequent changes in position without help Nutrition Usual food intake pattern 1. Very poor: Never eats a complete meal Rarely eats more than one third of any food offered Eats two servings or less of protein (meat or dairy products) per day Takes fluids poorly; does not take a liquid dietary supplement Or: Is NPO and/or maintained on clear liquids or IV infusions for more than 5 days 2. Probably inadequate: Rarely eats a complete meal and generally eats only about half of any food offered Protein intake includes only three servings of meat or dairy products per day Occasionally takes a dietary supplement Or: Receives less than optimal amount of liquid diet or tube feeding 3. Adequate: Eats over half of most meals Eats a total of four servings of protein (meat, dairy products) each day Occasionally refuses a meal but usually takes a supplement when offered Or: Is on a tube-feeding or TPN regimen that probably meets most of nutritional needs 4. Excellent: Eats most of every meal Never refuses a meal Usually eats a total of four or more servings of meat and dairy products Occasionally eats between meals Does not require supplementation Friction and Shear 1. Problem: Requires moderate-to-maximum help to move Complete lifting without sliding against sheets impossible Frequently slides down in bed or chair; repositioning with maximal help Spasticity, contractions, or agitation leads to almost constant friction 2. Potential problem: Moves feebly or requires minimal help During a move skin probably slides to some extent against sheets, chair, restraints, or other devices Maintains relatively good position in chair or bed most of the time but occasionally slides down 3. No apparent problem: Moves in bed and chair independently and has sufficient muscle strength to sit up completely during move Maintains good position in bed or chair

Maintaining an Airtight Seal With Negative-Pressure Wound Therapy

• Clip hair on skin around wound (check agency policy). • Fill uneven skin surfaces with a skin-barrier product such as paste or strips. • Make sure that periwound skin surface is dry. • Cut transparent film to extend 2.5 to 5 cm (1-2 inches) beyond wound perimeter. • Frame periwound area with skin sealant, solid skin barrier, hydrocolloid, or transparent film dressing. • Cut or mold transparent dressing to fit wound. • Avoid wrinkles when applying transparent film. • Identify any air leaks with a stethoscope and repair them with a sealant dressing (e.g., transparent dressing). Use only one or two additional layers for large leaks. Multiple layers reduce moisture vapor transmission and cause maceration of wound. • If an adhesive remover is used, be sure to cleanse periwound well because it leaves a residue that can hinder film adherence.

pressure injury principles for practice

• Pressure injuries occur from unrelieved, prolonged soft tissue compression, which interferes with blood flow to the tissue; if this compression continues for a prolonged period of time, the tissue dies from lack of blood flow, or tissue ischemia. Ischemia develops when pressure on the skin is greater than vascular pressure inside the vessels, causing the vessels to collapse and decreasing tissue perfusion. • The most common sites for the development of pressure injuries are over bony prominences and can include the sacrum, coccyx, ischial tuberosities, greater trochanters, heels, scapula, iliac crests, and lateral and medial malleoli (Pieper, 2016). Fig. 40.1 shows pressure points over bony prominences where pressure injuries can develop in sitting or lying positions. • Pressure injury can occur on any skin area subjected to pressure over nonbony locations from a poorly positioned or ill-fitting device or incorrect device use. These types of skin injuries are called medical device-related pressure injuries (MDRPIs). They have been defined as those that result from devices designed and applied for diagnostic or treatment purposes and generally conform to the shape of the device (WOCN, 2016). • MDRPIs are pressure injuries that can cause pain, loss of function, increased length of stay, and increased health care costs. Timely assessment of risk for or actual MDPRI provides for prompt prevention or treatment (The Joint Commission, 2018). • Factors such as incontinence and shear contribute to pressure injury formation. Chronic moisture from fecal and urinary incontinence compromises the protective barrier of the skin and may overhydrate it, making skin more susceptible to breakdown. Shear can damage the skin in one of two ways: shear stress, defined as the force per unit area exerted parallel to the plane of interest, and shear strain, defined as the distortion or deformation of tissue as a result of shear stress (EPUAP, NPIAP, PPPIA, 2019a, 2019b). • Shear stress can result in skin tears (shearing of the epidermal layer from the dermal layer, such as inappropriate tape removal) or in deep damage, such as pressure injuries. Shear strain occurs when the subcutaneous tissue shears against the dermal layer, distorting the blood vessels (e.g., when the patient slides down in bed causing deep tissue injury) (Doughty and Sparks-Defriese, 2016). • Other risk factors that can contribute to the development of pressure injuries include immobility, loss of sensory perception, decrease in activity, and malnutrition (EPUAP, NPIAP, PPPIA, 2019a): • Immobility often restricts a patient's ability to change and control body position, thus increasing the pressure over bony prominences. • Loss of sensory perception decreases the individual's ability to respond to increased, prolonged pressure in an area of the body and change positions accordingly. • Level of activity refers to the person's normal physical movement. A person who is bed bound is at greater risk for skin breakdown than a person who is fully or partially mobile. • Research indicates that malnutrition contributes to the development of pressure injuries (WOCN, 2016). • Pressure injuries pose serious risks to a patient's health. A break in the skin, seen in categories/stages 2 to 4 pressure injuries (Box 40.1), eliminates the first line of defense of the body against infection. • Reports vary as to the number of patients who are at risk for and develop pressure injuries, but the number of patients who develop them is significant. Patients are now older and sicker, are hospitalized for shorter periods of time, and are discharged to home or intermediate or long-term care facilities at a more acute stage of illness (Pieper, 2016). These changes contribute to an increased number of patients at risk for developing pressure injuries. Thus it is critical to respond with an aggressive preventive approach. As a nurse you must identify the factors that place your patients at risk for the development of pressure injuries. Once you identify these factors, begin interventions to reduce or relieve the negative effects of each factor. • When a pressure injury develops, explore the factors that contributed to skin breakdown, vigorously attempt to minimize the effects of these variables, and use current wound-healing principles in the management of injuries (see Chapters 39 and 41).

principles for practice

• The skin is the largest external organ. It has two layers: the epidermis and the dermis (Fig. 39.1). The epidermis has five layers. • Stratum corneum, the outermost layer, consists of flattened dead keratinized cells. Stratum corneum prevents dehydration of underlying cells and is a physical barrier to the entry of certain chemicals. This layer is like the shingles on a roof that provides protection from outside elements. • The next layers of the epidermis are the stratum lucidum, stratum granulosum, and stratum spinosum. • Stratum germinativum, the innermost layer, is sometimes called the basal layer. Important features of the stratum germinativum are the epidermal protrusions, or "peaks and valleys" that point downward into the dermis. These provide resiliency and integrity to the skin structure. Melanocytes, the cells that give the skin its color, are also in this layer. • The area that separates the epidermis from the dermis is called the dermoepidermal junction or the basement membrane zone. • Beneath the epidermis is the dermis. Collagen (a tough fibrous protein layer), blood vessels, and nerves compose the dermal layer. Collagen composes about 70% of the dermis and is extremely important in wound healing. The dermis restores the physical properties of the skin and its structural integrity. Restoration of both the epidermal and dermal layers is necessary to promote healing. Risk for local or systemic infection, impaired circulation, and breakdown of tissue directly impairs the wound-healing ability of the skin layers (Doughty and Sparks-Defriese, 2016). • Wounds should be assessed on a scheduled basis to determine if the wound is moving toward healing. If the assessment reveals that the wound is not progressing as expected, the plan of care can be changed to facilitate wound healing (see Procedural Guideline 39.1). • A thorough wound assessment includes the identification of the type of wound healing (e.g., primary, secondary, or tertiary intention), the type of tissue in the wound base, and the condition of the wound; these parameters will be used to choose the proper wound intervention. • A thorough head-to-toe skin assessment should be done on admission, daily, and if there is a change in patient's condition. All skin should be inspected closely, as a patient may not be aware of an issue with the skin because it is hidden under the clothes, or on the back. The healing process proceeds in a series of events, generally described as phases. In a full-thickness wound the phases are hemostasis, inflammation, proliferation, and remodeling (Box 39.1). • During the proliferative stage, fibroblasts are at the site of injury. These fibroblasts increase synthesis of collagen, which forms the healing ridge that can be palpated under an intact healing incision by days 5 to 9 (Fig. 39.2) (Doughty and Sparks-Defriese, 2016). • Wound healing occurs by primary, secondary, and tertiary intention (Fig. 39.3). • Healing by primary intention occurs when the edges of a clean surgical incision remain close together. The wound heals quickly, and tissue loss is minimal or absent (Doughty and Sparks-Defriese, 2016). The skin cells regenerate quickly, and capillary walls stretch across under the suture line to form a smooth surface as they join. • Wounds that are left open and allowed to heal by scar formation are classified as healing by secondary intention (Beitz, 2016). There is tissue loss and open wound edges. Granulation tissue gradually fills in the area of the defect (Fig. 39.4). This process is seen in a contaminated surgical wound such as a leak of a bowel anastomosis or massive surgical intervention with skin loss. • In secondary intention there is a gap between the edges. Connective tissue develops, which supports new capillaries. This form of healing results in the formation of scar tissue to close the wound. The slowness of this process places a patient at greater risk for infection because there is no epidermal barrier until later in the healing process. • Healing by tertiary intention is sometimes called delayed primary intention or closure. It occurs when surgical wounds are not closed immediately but are left open for 3 to 5 days to allow edema or infection to diminish. Then the wound edges are sutured or stapled closed (Doughty and Sparks-Defriese, 2016). • The percentage and type of tissue in the wound bed that is healing by secondary intention provide insight into the severity and duration of the wound, the extent to which it is progressing toward healing, and the effectiveness of current interventions (Nix, 2016). Viable tissue is normally red to pink in color and moist in appearance (Table 39.1). This type of tissue is called granulation tissue and indicates a wound moving toward healing. Black, brown, or tan tissue in the wound is slough or eschar and should be removed, or wound healing will be delayed. • The location, severity and extent of the injury and the tissue layer or layers involved all affect the wound-healing process (Doughty and Sparks-Defriese, 2016). In addition, there are underlying factors that prevent the ability of cells and tissues to regenerate, return to normal structure, or resume normal functioning (Box 39.2). • Partial-thickness wounds (loss of tissue limited to epidermis and possible partial loss of the dermis) heal by the process of regeneration. • Full-thickness wounds (total loss of skin layers and some deeper tissues) heal by scar formation. dorsal horn

negative-pressure wound therapy

-Negative-pressure wound therapy (NPWT) or vacuum-assisted closure (one brand name is V.A.C.) is the application of a subatmospheric (negative) pressure to a wound through suction to facilitate healing and collect wound fluid (Netsch et al., 2016). NPWT (Figs. 39.9 and 39.10) supports wound healing by removal of wound exudates and reduction of edema, macrodeformation and wound contraction, and microdeformation and mechanical stretch perfusion. Secondary effects include angiogenesis, granulation tissue formation, and reduction in bacterial bioburden (Netsch et al., 2016). The V.A.C. Instill system allows intermittent instillation of fluids into a wound and liquefies infectious material and wound debris, especially in wounds not responding to traditional NPWT (Fernandez et al., 2019). -Indications for NPWT include chronic, acute, traumatic, subacute, and dehisced wounds; partial-thickness burns; injuries (e.g., diabetic and pressure); flaps and grafts once nonviable tissue has been removed; and select high-risk postoperative surgical incisions (e.g., orthopedic, sternal). NPWT is also used in wounds with tunnels, undermining, or sinus tracts as long as the wound filler can fill the dead space and is easily retrieved (Netsch et al., 2016). Research also supports the use of an instillation of wound-rinsing agents to facilitate healing in some chronic wounds (Matiasek et al., 2018). -Contraindications to NPWT include necrotic tissue with eschar present; untreated osteomyelitis; nonenteric and unexplored fistulas; malignancy in the wound; exposed vasculature; and exposed nerves, anastomotic site, or organs. Other safety precautions to consider are patients at high risk for bleeding or hemorrhage; patients taking anticoagulants; and patients requiring magnetic resonance imaging (MRI), hyperbaric chamber, or defibrillation (Netsch et al., 2016). -There are a number of different NPWT systems, some of which are gauze or foam based; some are designed for acute care settings or for outpatient care (Netsch et al., 2016). NPWT can be delivered intermittently or continuously. Review of evidence show improved microvascular blood flow and granulation tissue formation with intermittent versus continuous therapy delivered at 125 mm Hg (WOCN, 2016). However, for patients with severe pain, lower levels of pressure (75-80 mm Hg) can be used to reduce pain and discomfort without compromising effectiveness (EPUAP/NPIAP/PPPIA, 2019a; EPUAP/NPIAP/PPPIA, 2019b; Netsch et al., 2016).

Yellow wounds/slough

-Yellow tissue represents nonviable tissue and in some cases the presence of an infection. Slough tissue can be yellow; cream colored; or gray slough, which is usually accompanied by purulent drainage. -For patients with a low infection risk, the use of moisture-retentive dressings enhances debridement of the yellow/slough tissue. Moisture-retentive dressings may include moist dressings, hydrocolloids, hydrogels, or alginates. If the wound is infected, topical antimicrobials are used.

Patient-Centered Care for Skin Assessment of Pressure Injuries: Patients With Darkly Pigmented Skin

1. Use natural lighting but note that visual inspection techniques to identify pressure injuries are ineffective in darkly pigmented skin. 2. Carefully inspect any discoloration over pressure areas and surrounding skin for temperature changes, edema, change in tissue consistency, and pain (EPUAP, NPIAP, PPPIA, 2019a). Assess localized skin color changes. Any of the following may appear: • Color remains unchanged when pressure is applied. • Color changes occur at site of pressure, which differ from patient's usual skin color. • If patient previously had a pressure injury, that area of skin may be lighter than original color. • Localized area of skin may be purple/blue or violet instead of red. Purple or maroon discoloration may indicate deep tissue injury (WOCN, 2016). 3. Assessment of skin temperature changes: Circumscribed area of intact skin may be warm to touch. As tissue changes color, intact skin will feel cool to touch. NOTE: Gloves may decrease sensitivity to changes in skin temperature (EPUAP, NPIAP, PPPIA, 2019a; WOCN, 2016). • Localized heat (inflammation) is detected by making comparisons to surrounding skin. Localized area of warmth eventually will be replaced by area of coolness, which is a sign of tissue devitalization. 4. Edema may occur with induration of more than 15 mm in diameter and may appear taut and shiny. 5. Palpate tissue consistency in surrounding tissues to identify any changes in tissue consistency between area of injury and normal tissue (EPUAP, NPIAP, PPPIA, 2019a). 6. Patient complains of discomfort at a site that is predisposed to pressure injury development (e.g., bony prominence, under medical devices).

Staging of pressure injuries

Stage 1 Pressure Injury: Nonblanchable Erythema of Intact Skin Intact skin with a localized area of nonblanchable erythema, which may appear differently in darkly pigmented skin. Presence of blanchable erythema or changes in sensation, temperature, or firmness may precede visual changes. Color changes do not include purple or maroon discoloration; these may indicate deep tissue pressure injury (EPUAP, NPIAP, PPPIA, 2019b). Stage 2 Pressure Injury: Partial-Thickness Skin Loss with Exposed Dermis Partial-thickness loss of skin with exposed dermis. The wound bed is viable, pink or red, and moist and may also present as an intact or ruptured serum-filled blister. Adipose (fat) and deeper tissues are not visible. Granulation tissue, slough, and eschar are not present. These injuries commonly result from adverse microclimate and shear in the skin over the pelvis and shear in the heel. This stage should not be used to describe moisture-associated skin damage (MASD), including incontinence-associated dermatitis (IAD), intertriginous dermatitis (ITD), medical adhesive-related skin injury (MARSI), or traumatic wounds (skin tears, burns, abrasions) (EPUAP, NPIAP, PPPIA, 2019b). Stage 3 Pressure Injury: Full-Thickness Skin Loss Full-thickness loss of skin, in which adipose (fat) is visible in the injury and granulation tissue and epibole (rolled wound edges) are often present. Slough and/or eschar may be visible. The depth of tissue damage varies by anatomical location; areas of significant adiposity can develop deep wounds. Undermining and tunneling may occur. Fascia, muscle, tendon, ligament, cartilage, and/or bone are not exposed. If slough or eschar obscures the extent of tissue loss, this is an Unstageable Pressure Injury (EPUAP, NPIAP, PPPIA, 2019b). Stage 4 Pressure Injury: Full-Thickness Skin and Tissue Loss Full-thickness skin and tissue loss with exposed or directly palpable fascia, muscle, tendon, ligament, cartilage, or bone in the injury. Slough and/or eschar may be visible. Epibole (rolled edges), undermining, and/or tunneling often occur. Depth varies by anatomical location. If slough or eschar obscures the extent of tissue loss, this is an unstageable pressure injury (EPUAP, NPIAP, PPPIA, 2019b). Suspected Deep Tissue Injury Purple or maroon localized area of discolored, intact skin or blood-filled blister due to damage of underlying soft tissue from pressure and/or shear. The area may be preceded by tissue that is painful, firm, mushy, boggy, or 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. Evaluation may be rapid exposing additional layers of tissue even with treatment (EPUAP, NPIAP, PPIA, 2019a). Unstageable Pressure Injury Obscured Full-Thickness Skin and Tissue Loss Full-thickness skin and tissue loss in which the extent of tissue damage within the injury cannot be confirmed because it is obscured by slough or eschar. If slough or eschar is removed, a stage 3 or 4 pressure injury will be revealed. Stable eschar (i.e., dry, adherent, intact without erythema or fluctuance) on the heel or ischemic limb should not be softened or removed.

Factors that Influence Wound Healing

• Hypovolemia, hypotension, vasoconstriction, edema, and hypoxia negatively affect wound healing because adequate perfusion and oxygenation are necessary for new vessel development, collagen synthesis, and development of tensile strength. • An adequate nutritional status is critical for collagen synthesis, tensile strength, and immune function. • Wound infection prolongs the inflammatory response, and the microorganisms use nutrients and oxygen needed for wound repair. • A patient with diabetes mellitus may have impaired wound healing because of abnormal and prolonged inflammation, reduced collagen synthesis, and impaired epithelial migration. Hyperglycemia is associated with compromised neutrophil function and impaired migration. • Corticosteroid therapy or the use of other immunosuppressive agents such as chemotherapy increases the patient's susceptibility to infection. • Advanced age can contribute to a diminished proliferation of cells critical to repair.