#48853: Pressure Injuries: Prevention and Management

Pressure that results in injury and subsequent skin breakdown is defined as compression of soft tissues between two rigid surfaces. For example, skin, muscle, subcutaneous fat, and vasculature may be compressed between an underlying boney prominence and a rigid external surface, such as a bed or chair. All the tissues between the two points of pressure are affected, but the tissue closest to the bony prominence suffers the greatest damage. It is important to note that low-intensity pressure over a long period of time can create tissue damage, just as high-intensity pressure over a short period of time can result in damage [10].

The capillary level is the end point of circulation. From the capillaries, oxygen and nutrients diffuse into the tissues, and carbon dioxide and waste products are removed. A collapsed capillary bed is nonfunctioning and useless to the tissues. The minimal amount of pressure required to collapse a capillary is referred to as the capillary closing pressure [13]. Studies have shown that an average of 32 mm Hg will collapse the arterial side of the capillary circulation, and 18 mm Hg of pressure will collapse the venous end. However, these values cannot be accepted as universal; capillary pressures vary among persons, sites, and times [10]. Furthermore, the studies that elicited these values were done on healthy adult males, not debilitated or elderly patients. Other studies have shown that the functional capillary pressure in the peripheral tissues is around 17 mm Hg [14]. Extended pressure resulting in capillary collapse will cause tissue damage.

Shear is the result of gravity pushing down on the body and resistance (friction) between the patient and a surface, such as the bed or the chair, holding the skin in place [10]. For example, when the head of the bed is raised (e.g., high Fowler's position), gravity facilitates forward slide, pulling the body down toward the foot of the bed. The skin on the patient's lower back and gluteal area resists the motion and is held in place by the bed's surface while the bones and tissues beneath the area begin to slide. This causes puckering of the skin, stretching and angulation of small vessels, impedance of blood flow, and traction on subcutaneous tissue and muscle. Left unchecked, the net effect may result in ischemic injury to tissues at the fascia layer. When the head of the bed is elevated more than 30 degrees, shear force occurs over the sacrum and coccyx. Shear injury is not usually visible at the skin level, but shear is responsible for much of the damage associated with initiation of pressure injuries [15]. The areas of the body most vulnerable to shearing forces are shoulder blades, elbows, sacrum, ischial tuberosities, and heels. Signs of shear injury include irregular deep lesions, undermining, and tunneling.

As noted, friction occurs when one surface moves across another surface, such as when a patient's skin slides across a bed sheet. This can result in the "sanding away" of the epidermal layer and upper part of the dermis, causing abrasions [10]. Friction injuries often present as erythema and tenderness followed by skin loss and usually appear under restraints, braces, and on the elbows, or with repetitive rubbing or repetitive cleansing. Patients with uncontrollable movements or spasticity are also at high risk for friction injury, often referred to as "sheet burn." Friction injury occurs more frequently when the skin is fragile or macerated, and tissues subjected to friction are more susceptible to pressure injury damage [15].

Moisture weakens the resilience of the epidermis to external forces. Maceration causes softening of the connective tissue, and a macerated epidermis erodes more easily, as overhydrated skin has decreased tensile strength. Skin can appear "water-logged," with areas of denuded skin and fissure formation. Shear and friction damage is increased when there is a moderate amount of moisture present, but it has been reported that shear and friction decrease in the presence of high levels of moisture. The role moisture plays in pressure injury development is an area of ongoing research [16,17,18].

Major sources of moisture are incontinence, wound drainage, tube leakage, and sweating. Urinary and fecal incontinence expose the skin to excessive amounts of moisture and chemical irritation. There is a higher risk for skin breakdown and infection with fecal incontinence than urinary incontinence because of the pathogens in stool.

Patients older than 65 years of age experience pressure injuries most frequently [13]. With aging, the skin becomes more fragile; the skin layers adhere less securely to each other and can appear paper thin and almost transparent. There is also evidence of increased dryness, decreased vascularization, and increased vascular fragility.

In elderly individuals, there is a decrease in surface barrier function. The ability of the soft tissue to evenly distribute the mechanical load without compromising blood flow is impaired. There is less subcutaneous tissue to cushion boney prominences. This, in addition to decreased sensory perception, makes elderly skin more vulnerable to pressure, shear, and friction [10]. Research has shown that, in the geriatric population, blood flow in the area of the ischial tuberosity while sitting on an unpadded surface is lower than in younger adults [15].

Although much less common, children can also develop pressure injuries. These injuries usually develop in the occipital region in infants and toddlers and on the sacrum in young children [13].

Immobile individuals carry the greatest risk of developing pressure injuries. While sleeping, a healthy individual changes body position approximately once every 10 to 12 minutes. This constant change of position maintains healthy blood circulation, stimulates body organs, and ensures movement of body fluids. However, when an individual is immobile, decreased vascularization and prolonged pressure pair with possible loss of sensation to make the patient extremely vulnerable to pressure injuries. Immobility may be the result of multiple traumas or injuries, spinal cord injuries, stroke, prolonged hospitalization, coma, recovery after surgery, or cognitive deficits [15].

Patients with spinal cord injury, neurologic disease, or even advanced diabetes carry an increased risk of developing pressure injuries as a result of loss of protective sensation. Patients with sensory loss may not feel discomfort or the need to be repositioned.

Poor nutrition, intravascular volume depletion, and peripheral vascular disease can each lead to unhealthy skin and impaired wound healing, which in turn increases the risk of developing pressure injuries. Low body weight is also a concern. Weight less than 119 pounds or a body mass index (BMI) less than 20 indicates increased risk for pressure injury development [19].

Recent weight loss, decreased nutritional intake, inadequate dietary protein, and impaired ability to feed oneself have been identified as risk factors for pressure injury development. An estimated 50% of elderly patients admitted to hospitals have suboptimal protein nutrition [19]. When there is a sustained deficit of protein as an energy source, skin and soft tissues become more vulnerable to injury. In managing patients with pressure injury, or those at risk, the amount of protein in the diet appears to influence prognosis for recovery and prevention. In one study, patients who received a 24% increase in protein intake had significant improvements in pressure injury healing and prevention of new skin injury compared to those who received a 14% increase [20]. The potential role of nutritional supplementation on pressure injury management and prevention is an area of ongoing research [21,22].

Vitamin A, C, and E deficiencies have been associated with pressure injury formation. Vitamin A works in the body to maintain epithelial integrity and is involved in collagen synthesis. It also plays a role in protection against infection. A deficiency of vitamin A can inhibit collagen synthesis, delay re-epithelialization, and decrease cellular cohesion. Vitamin C is also involved in collagen synthesis, immune function, and wound repair. A deficiency of vitamin C can result in capillary fragility. Vitamin E deficiency often decreases the immune function of the skin.

Both urinary incontinence and bowel incontinence can result in excessive moisture on the skin, which decreases the tensile strength and increases skin breakdown. In addition, infection may occur more frequently.

Maintenance of tissue health requires an adequate perfusion pressure in the systemic circulation for delivery of oxygen and nutrients to the cells and removal of waste products. Healthy tissue (in persons with normal sensation and movement) is able to tolerate brief, intermittent periods of inadequate perfusion; however, sustained ischemia leads to tissue damage and, with regard to skin, potentiates the development of pressure injuries.

Low arterial blood pressure (hypotension), defined as systolic blood pressure less than 100 mm Hg and diastolic pressure less than 60 mm Hg, has been linked to increased risk for pressure injury development. In response to hypotension, the body redirects blood flow to the vital internal organs at the expense of the peripheral vascular system, which serves the skin. As the perfusion level drops, so does the skin's ability to tolerate external pressure. Capillaries subsequently close at lower levels of interface pressure, and there is an increased risk of damage due to ischemia [13].

Nicotine impedes blood flow to the tissues in two ways: it is a potent vasoconstrictor, and it increases the adhesiveness of platelets, resulting in clot formation. Carbon monoxide contained in cigarette smoke prevents oxygen from attaching to the hemoglobin molecule. This significantly reduces the amount of oxygen circulating in the blood stream. The same reaction occurs to some extent in people exposed to secondhand smoke. Studies have shown that cigarette smoking is associated with a higher incidence of pressure injury development, and patients who smoke also have a higher rate of recurrence of pressure injuries [15,23].

Stress is a primitive response to injury or anticipated injury. Research has shown that during periods of stress, blood vessels in the peripheral tissues constrict. In a study designed to mimic the body's response to stress, healthy subjects were given an infusion of exogenous epinephrine [13]. The increased levels of epinephrine decreased the levels of subcutaneous tissue oxygen by 45%. Other studies have shown that psychologic stress has a negative impact on healing [13].

In the United States in 2017–2018, the age-adjusted prevalence of obesity among adults was 42.4% [24]. Obesity is defined as a BMI of 30 or greater; morbid ("severe") obesity is defined as a BMI greater than 40 [25]. Factors that contribute to pressure injury development in obese individuals include decreased blood supply in adipose tissue, difficulty in turning and repositioning, moisture within skin folds, incontinence, skin-to-skin friction, immobility, and poor nutrition. Obese patients are particularly at risk for "unusual" pressure injuries resulting from pressure within skin folds. Obese patients may have large panniculi ("aprons") weighing up to 50 pounds, and the abdominal panniculus must be regularly repositioned in order to prevent pressure injury. This can be accomplished by placing the patient on his or her side and lifting the panniculus away from the underlying skin surface in order to simultaneously relieve pressure and allow air to reach the area.

People with severe mental health conditions, such as uncontrolled schizophrenia or severe depression, have an increased risk of pressure injuries. This is thought to be related to these patients having little interest in self-care and nutrition. In addition, patients may have comorbid health conditions, such as diabetes or incontinence, that compound the risk of pressure injury development.

Chronic disease often confers multiple risk factors for developing a pressure injury and for prolonging injury healing as well. Conditions that lead to low tissue perfusion, reduced sensation, poor cognition, and altered posture predispose a patient to the development and/or recurrence of injuries. Common medical conditions associated with an increased risk for pressure injury include:

Tubes or catheters can also cause pressure by burrowing into skin folds. Poorly fitting bed, chairs, or wheelchairs may also be a source of friction, shear, and sustained pressure [26].

The Braden Scale was developed in 1987 by Barbara Braden and Nancy Bergstrom [27]. Since then, it has undergone testing in several clinical settings, and its validity has been established by expert opinion. It is considered one of the most reliable tools for identifying patients at risk for pressure injury development. The Braden Scale scores factors that contribute to prolonged pressure and factors that result in diminished tissue tolerance for pressure (Table 1) [27]. There are six items scored in the assessment [27]:

Each item is scored on a scale between 1 and 4, with the exception of friction and shear, which is scored between 1 and 3. The lower the score, the more severe the impairment or problem in that area. Therefore, the lower the overall score, the higher the patient's risk for pressure injury development. Various studies have shown cut-off scores from 15 to 18 as being at risk [10]. Although cut-off scores vary, usually a score of 13–14 is considered moderate risk, 10–12 indicates high risk, and 9 or less is very high risk.

The Braden Scale should be used for assessment on admission to a care facility or after return from a hospital. Research shows that a repeat assessment done 48 hours to 72 hours after admission further defines pressure injury risk. In nursing home populations, the majority of pressure injuries develop during the first two weeks following admission [13]. Most facilities set their own policies regarding reassessment frequency (e.g., quarterly). However, it is important to note that any change in a patient's condition warrants reassessment.

Braden Scale assessment is completed by licensed personnel familiar with the patient and is shared with all staff caring for the patient; good communication is essential to ensure a meaningful assessment [15]. Licensed and unlicensed staff must have a basic knowledge of Braden scores and how it directs patient care. Accuracy of scoring is very important to determining the appropriate intervention.

The Norton Scale was developed in the 1960s and also is used to assess the risk for pressure injury in adults (Table 2). The five items in the assessment are scored from 1 to 4, with 1 indicating a low level of functioning and 4 indicating the highest level of functioning. A score of 14 or less generally indicates the patient is at risk [28]. The Norton Scale should be used in conjunction with the clinical assessment [28].

Bedbound Patients

Bedbound patients should be properly positioned and frequently repositioned, at least every two hours. When in lateral decubitus position, patients' heads should be maintained at an angle of 30 degrees in order to mitigate pressure in the trochanteric region. Pillows or foam wedges should be placed between the legs, at the knees and ankles, to prevent pressure at these sites when patients have little or no ability to move legs and feet.

To the extent the patient is able, regular physical activity should be encouraged and assisted. Even a few steps done frequently will help maintain current activity level, mobility, and range of motion. Lifting devices, such as an overhead trapeze or bed linen, are helpful when moving patients. It is important to avoid or minimize dragging the patient during transfers and position changes. Patients require protection from environmental factors leading to skin drying, such as low humidity (less than 40%) and exposure to cold [15]. Posting an individualized turning schedule in patient rooms can be helpful to healthcare professionals and families.

The heels are especially vulnerable, and pressure injuries at this location are very painful, difficult to heal, and prone to infection with easy access to adjacent bone. Heel pressure injuries can develop infection, and advanced cases may lead to amputation of the foot. To protect the heels, place a pillow under the calf to float the heels off the bed. There are also devices available that eliminate pressure on heels and prevent foot drop (e.g., suspension boots). Current guidelines state that heels are to be kept off the bed [10,36].

Chairbound Patients

The National Pressure Ulcer Advisory Panel, the European Pressure Ulcer Advisory Panel, and the Pan Pacific Pressure Injury Alliance recommend using a pressure redistribution cushion for preventing pressure injuries in people at high risk who are seated in a chair/wheelchair for prolonged periods, particularly if the individual is unable to perform pressure-relieving measures.

(https://www.internationalguideline.com/static/pdfs/Quick_Reference_Guide-10Mar2019.pdf Last Accessed: April 22, 2022)

Level of Evidence: B1 (The recommendation is supported by level 1 studies of moderate or low quality providing direct evidence or level 2 studies of high or moderate quality providing direct evidence)

Chairbound patients require special attention to positioning as well. The risk of pressure injuries from prolonged sitting is greater than that from reclining in bed, as sitting puts the patient's weight on the relatively small surface areas of the buttocks, thighs, and soles of the feet. Much of this weight is centered over the small area of tissue covering the ischial tuberosities. It is important for patients who sit in a chair to regularly change position. A dependent patient must have his/her position changed in a chair at least every hour. Patients who are able to move themselves should shift their weight (even slightly) every 15 minutes.

A patient should be properly positioned in a chair for postural alignment, distribution of weight, balance, and stability. Patients should sit with their back erect and against the back of the chair, thighs parallel to the floor, knees comfortably parted, and arms horizontal and supported by the arms of the chair. This position distributes weight evenly over the available body surface area. Slouching can cause shearing and friction and places undue pressure on the sacrum and coccyx. Feet should be kept flat on the floor to protect the heels from pressure and distribute the weight of the legs over the largest available surface area. The thighs and arms should remain parallel to ensure that weight is evenly distributed instead of being focused on the ischial tuberosities and elbows. Parting the knees will prevent the knees and ankles from rubbing together. If a patient uses a footstool, it is vital that his or her knees are not above hip level, because this shifts the weight from the back of the thighs to the ischial tuberosities. This same problem can occur if the chair is too short for the patient.

Protective padding and pillows should be utilized for pressure reduction whenever possible. Heel protectors, foam, and pillows can be helpful for patients in supine positions. Cutting a window through the cast can greatly reduce pressure at certain sites in patients immobilized by fractures. Patients should be provided soft seat cushions when sitting in a chair. Sheepskin and donut-shaped devices should not be used for treating pressure injuries; ring cushions can reduce blood flow to an even wider area of tissue.

Support surfaces are indicated when patients are not able to reposition themselves or when periodic repositioning care is not available. In a comprehensive literature review researchers founds good evidence that specially designed support surfaces effectively prevent pressure injuries [38].

An ideal support surface will manage microclimate, tissue loads, and other curative functions. Seat cushions, overlays, mattresses, and integrated bed systems are commonly used to prevent pressure injuries. The type of device or surface selected is based on level of risk as well as degree of assistance necessary for repositioning or mobility (Table 3).

Types of Support Surfaces

Overlays are filled with water, air, gel, or foam (or a combination of these products) and are applied to the top of a mattress. Foam overlays should be a minimum of 3 inches thick. If a patient's weight completely compresses an overlay, it is not effective.

Pressure relief mattresses are made of a combination of foam, water, or gel or layers of varying foam densities. They are usually indicated in place of standard mattresses used in hospitals and at home. Studies have shown that people at high risk of developing pressure injuries should use higher-specification foam mattresses instead of standard hospital foam mattresses [39].

Air-fluidized beds are embedded with tiny, silicone-coated beads suspended by pressurized, temperature-controlled air. They are recommended for immobile patients who carry higher risk for posterior pressure injuries. These beds reduce pressure against the patient's skin surface, resulting in increased capillary blood flow to the skin. This greatly increases granulation and healing of injuries. These beds are beneficial in patients with multiple large injuries; however, they are unsuitable for patients who are ambulatory, have pulmonary disease, or have spinal instability. They are usually used as an adjunct to comprehensive care.

Low-air-loss beds are made of numerous interconnected air-filled pillows designed to lose air through the cushions at a controlled rate. These beds distribute the patient's weight evenly, which in turn reduces friction, provides pressure relief, and increases capillary blood flow. They are indicated in patients with stage 3 or 4 injuries or stage 1 injuries with hyperemia.

Combination air-fluidized/low-air-loss beds combine the benefits of both types of beds. The low-air-loss component is placed on the upper half of the bed, while the air-fluidized component is placed on the lower half of the bed.

The most important consideration when choosing a support surface is ease of use. Patient goals and overall care plan are also considerations when selecting a support surface. Pressure injury risk, bed mobility, transfer, posture and positioning, financial resources, and advantages and disadvantages of the support surfaces should all be taken into account prior to coming to a decision.

For patients with inadequate nutrition, strategies should be employed to increase oral intake. The preferred route of nutritional support is oral; whenever possible, the gastrointestinal tract should be used for feeding. It is the easiest and most comfortable way to provide supplementation, and it is also the least expensive and most convenient way. Patients should have diets prescribed with protein and caloric content sufficient to meet metabolic needs, with consideration of the patient's preferences and special needs (e.g., mechanical soft diets) [15]. Daily multivitamin supplementation may be implemented. Mouth care should be performed prior to eating. Additionally, toileting and hand washing should be offered prior to meals.

It is important to provide an environment conducive to eating. Position the patient properly; an upright position is preferred. Make sure the food is at the right temperature for the patient. Do not rush eating, particularly if the patient is elderly and requires more time to be oriented. Many patients benefit from the inclusion of snacks high in calories and protein in the diet (e.g., a peanut butter sandwich with milk). Consider adding powdered milk to yogurt and puddings to maximize caloric intake and protein levels. Commercial nutritional supplements, such as breakfast shakes, are also a common adjunct.

It is vital to maintain patient control as far as medically feasible. Some patients may not like ice in their water; others may prefer soup lukewarm. Patient preferences should be accommodated as much as possible.

Remind the patient to chew food thoroughly. If necessary, liquids may be offered between bites; some patients require this to help swallow their food.

Assuring adequate fluids and the maintenance of intravascular volume homeostasis are equally important. Vigilance is required to detect early signs of volume depletion or dehydration (e.g., change in weight, loss of skin turgor, falling urine output, hypernatremia); patients identified to be at risk should be listed on assignment/report sheets as a reminder to monitor these patients closely. Fluids should be scheduled between meals at least three times a day. Patient preferences for fluids (e.g., straws, temperature, ice, etc.) should be observed and noted. Refill water pitchers frequently and keep them within reach of patients, especially those with restricted mobility. Patients should be offered something to drink at every interaction. Ambulatory patients should be provided with a water bottle. As with nutrition and positioning, it is necessary to educate patients/families about the importance of regular fluid intake. When, despite these measures, patients are unable to consume adequate levels of water or nutrients, tube feeding or parenteral feeding should be considered. Patient and family preferences and the overall goals of treatment guide these decisions [19].

Autolytic debridement uses the body's own enzymes and moisture to heal the injury. To be successful, there must be sufficient white blood cells available to the wound and a moist environment [13]. A layer of wound exudate should be kept in contact with the surface of the wound, usually using a moisture-retaining dressing [10,15,35]. This allows fluid to accumulate in the wound, rehydrating necrotic tissue and making it possible for enzymes in the wound to digest the dead tissue [35]. For a wound covered with dry eschar, it is appropriate to crosshatch the eschar, as this allows a faster build-up of moisture in the wound [35]. In their clinical practice guidelines for pressure injury treatment, the Agency for Healthcare Research and Quality recommends autolytic and enzymatic debridement as the preferred approach for patients in long-term care or home care and for patients who cannot tolerate other methods of debridement [35,46]. In general, this type of debridement is ideal for patients with stage 3 or 4 injuries with light-to-moderate exudates.

Autolytic debridement is highly selective; healthy tissue is spared and only necrotic tissue is liquefied. It is considered very safe, as it uses the patient's own immune system to promote healing and clean the wound of necrotic tissue. Autolytic debridement is easy to perform, very effective, and can be combined with other approaches. It is almost painless for the patient, making it a very attractive option.

However, there are disadvantages as well. It is comparatively slow in efficacy compared to surgical debridement, with progress usually seen in about one week [35]. Close monitoring of the injury is necessary to detect signs of infection. There is a risk of anaerobic growth when an occlusive hydrocolloid dressing is used, and this approach should not be used in infected injuries.

Mechanical debridement is a nonselective type of debridement that loosens and removes devitalized tissue and debris as well as viable tissue. This method is usually accomplished by means of mechanical force, such as wet-to-dry dressings, pulsatile lavage, or wound irrigation [31]. Pulse lavage may require special knowledge or training on equipment. Although it is a low-cost procedure, mechanical debridement is time consuming and can be painful.

Mechanical debridement is indicated for both acute and chronic wounds with moderate-to-large amounts of necrotic tissue, regardless of the presence of an active infection [47]. Depending on the modality used, the contraindications to mechanical debridement include the presence of granulation tissue in a higher amount than the devitalized tissue, inability to control pain, patients with poor perfusion, and an intact eschar with no gross clinical evidence of an underlying infection [47]. Mechanical debridement also is not indicated for clean wounds.

Surgical debridement is indicated for wounds with thick exudate and necrotic tissue. Approaches include hydrotherapy, laser, maggot debridement therapy (MDT), ultrasound, whirlpool, or excision (with a scalpel or scissors). Extensive or deep injuries should be debrided in operating rooms, although a moderate amount of necrotic tissue can be debrided at the bedside. Newer approaches, such as laser debridement, limit collateral damage, but these approaches can be prohibitively expensive [48]. Hydrotherapy can result in tissue maceration, and there is a risk of infection. Therefore, it is considered a less attractive option. The use of ultrasound waves to debride wounds also has been explored. With this technique, low-frequency ultrasound creates small bubbles in the wound that implode, causing the necrotic tissue to liquefy [49]. This method is generally less painful and less traumatic than traditional methods, with faster healing rates compared with other types of mechanical debridement [50]. However, further comparative evidence is necessary before it can be recommended as a replacement for established treatment modalities. Sharp surgical debridement is contraindicated in patients with intact eschar and no clinical evidence of an underlying infection [47]. The decision to attempt inpatient surgical debridement should take into account the patient's surgical risk stratification [47].

Debridement with maggots, an approach popular at the early 20th century, is finding a new place in wound care debridement [15]. MDT is an efficient, simple, cost-effective and reliable biosurgery method that uses mostly larvae of the Lucilia sericata species of the green bottle fly [51]. The larvae stimulate wound healing by activating molecular processes in the wound area through proteolytic enzymes, including collagenase, in their excretions/secretions that break down the necrotic tissue, ingest and digest micro-organisms, and inhibit bacterial growth by releasing ammonia into the would bed, which increases the wound pH [13,47]. Studies have shown that the excretions/secretions have antibacterial, antifungal, anti-inflammatory, and tissue-regenerating effects; the enzymes are still mostly unidentified [51]. Maggots have the ability to access moist tissue throughout the wound bed and clean small areas without harming healthy tissue [52]. MDT involves the application of sterilized larvae to the wound bed every two to three days [15]. The maggots can be applied to the wound directly or in a containment pouch [15]. The most appropriate dressing for wounds treated with maggots is one that keeps the larvae in place, allows for a flow of oxygen, and is suitable for the characteristics of the wound [35].

MDT is indicated for pressure injuries with necrotic tissue with or without infection [52]. Maggots work well in wounds in which moisture and oxygen are readily available and the pH is fairly stable [35]. The therapy is considered mainly for the treatment of wounds for which other forms of treatment are either not appropriate or not successful, and it is contraindicated in patients who have bleeding abnormalities or deep tunneled wounds [10,15,47].

Precautions should be taken to prevent the larvae from coming in contact with healthy skin, as there is a possibility of enzymatic damage [13]. Otherwise, there are no reported side effects from MDT [13]. However, some patients complain of a crawling or tingling feeling [13]. MDT also may cause psychologic distress for many patients, and its use should be discussed thoroughly with the patient and/or family prior to commencing therapy [15]. This therapy should only be used with appropriately informed consent.

Enzymatic debridement is a selective method of debridement in which concentrated enzymes (e.g., collagenase, papain, becaplermin, trypsin) attack collagen and liquefy necrotic wound debris without damaging viable tissue. Enzymatic debridement is used either alone or in combination with other techniques to remove necrotic tissue and promote wound healing [53,54]. For instance, collagenase and moisture retentive dressings can work in synergy, thereby enhancing debridement [47].

Usually, stage 3 or 4 injuries are considered candidates for enzymatic debridement. Application of the enzyme should be discontinued when the wound is free of necrotic tissue. If eschar is present, it should be crosshatched prior to introduction of the enzyme to improve efficacy, as enzymes are not active on a dry surface.

Enzymatic debridement is relatively fast acting, with progress evident in 48 to 72 hours. However, complete debridement may be a long process, so other methods (e.g., surgical removal of loosely adherent necrotic tissue) are often used in conjunction.

Enzymatic debridement should not be used for heavily infected wounds or in conjunction with silver-based products or Dakin solution [47].

For injuries with limited exudates, transparent films should be used; however, their use over cavities is contraindicated. These dressings should be changed every three to seven days, and application of triple antibiotic ointment is also recommended by some experts [55].

Hydrogel dressings are useful for patients with very shallow, dry, or minimally exuding injuries and for painful pressure injuries [29]. These gels, sheets, sprays, or ribbons of cross-linked polymers require a secondary dressing to affix them to the patient. Hydrogels not only rehydrate the wound bed but also aid autolytic debridement and reduce pain. These dressings can be used in infected injuries and are easily applied and removed from the wound. However, they are not recommended for pressure injuries with heavy exudation. They also dehydrate easily and can cause maceration.

Hydrocolloid dressings contain a gel that promotes the growth of new skin and are indicated for clean, uninfected stage 2 and shallow stage 3 injuries in body areas where they will not roll or melt [29]. They are available as pastes, powders, or wafers composed of gelatin, pectin, and carboxymethylcellulose. These dressings promote angiogenesis, autolysis, and granulation. Some hydrocolloids are self-adhering, but secondary dressings are required when powders and pastes are used. These dressings are especially beneficial on heels and sacral injuries that require contouring. They are recommended for partial and full-thickness injuries with or without necrotic tissue.

Hydrocolloid dressings can produce an odor upon removal [15]. In the absence of other signs of clinical infection, this is not an abnormal finding and should be explained to concerned patients and staff [15]. Hydrocolloids may also leave a residue in the wound bed, which should be gently irrigated out at dressing change [13]. These dressings lose their effectiveness if they are changed too frequently and should not be used for wounds that must be monitored daily [13].

Calcium alginate dressings, or alginates, are polysaccharide seaweed derivatives containing alginic acid. Alginate dressings either form a moist gel when they come in contact with exudates or retain their original shape while absorbing exudates. They are hemostatic, protect surrounding skin from maceration, promote healing, and may reduce risk of infection. These dressings are available in the form of ribbons, pads, and ropes.

Alginate dressings should be considered for the treatment of moderately and heavily exuding pressure injuries and for clinically infected injuries when there is concurrent antimicrobial therapy [29]. They may also be used to control bleeding after surgical debridement. A secondary dressing is necessary to secure these dressings, and they should be changed every 12 hours to four days. Wounds treated with alginate dressings may smell fishy or like "low tide" [15].

Foam dressings are protective and absorbent and potentiate wound healing by providing a moist environment. They are also permeable to gas and provide good insulation. These dressings are a good choice for stage 2 and shallow stage 3 injuries with drainage and for painful injuries.

In patients with incontinence, waterproof versions of foam dressings are prescribed in order to protect the skin. They can also be used under compression to prevent damage from shear. However, foam dressings are not effective in removing necrotic tissue, and after the dressing becomes saturated, maceration of skin around the wound can develop quickly. Therefore, these dressings should be paired with alginates for wounds with a high level of exudate.

Silver-impregnated dressings are a treatment option for infected or heavily colonized wounds or wounds that are at increased risk for infection [29]. Silver has an antimicrobial effect on a broad spectrum of organisms and has been shown to reduce the bacterial count in wounds [13]. Sustained-release sliver dressings are toxic to bacteria and fungi but do not adversely affect healthy wound tissue [10]. However, silver-resistant organisms do exist, and the judicious use of silver is advised, similar to the approach adopted with antibiotics [13]. It is recommended that the use of silver dressings be limited to a two- to four-week period [13]. As stated, silver-based products should not be used for enzymatic debridement [47].

Cadexomer iodine dressings are used for wounds with moderate-to-high amounts of drainage. They should not be used for patients who are sensitive to iodine or individuals with thyroid disease [29]. Cadexomer iodine dressings are antimicrobial and maintain a moist environment for wound healing [15]. Although these dressings are capable of reducing bacteria counts in wounds, they do not replace the need for systemic antibiotic therapy and are regarded as an adjunct in the treatment of wound infections [15].

Gauze packing was used frequently in the past, but it is now regarded as less effective in coping with wound drainage than calcium alginate or hydrocolloid fiber dressings [10]. Gauze dressings do not provide a barrier against bacteria, lower wound temperature, and can pull healthy granulating tissue out of the wound on removal [10]. When other forms of moisture-retentive dressings are not available, continually moist gauze is preferable to dry gauze, and one should avoid the use of wet-to-dry gauze dressings [29]. Gauze dressings are also labor intensive, requiring several dressing changes daily, which adds to the cost of the overall care [15].

Composite dressings are a combination of more than one material used to fulfill several important functions in the wound [15]. They provide an effective barrier to bacterial contamination of the wound and include an absorptive layer and either foam, hydrocolloid, or hydrogel [15]. Composite dressings can have either a semi-adherent or non-adherent surface placed in contact with the wound bed [15]. Composite dressings are comfortable and are available in various shapes and sizes [13]. These dressings should not be cut, as this compromises the structure of the dressing [15].

Some dressings incorporate collagen, which is an important protein involved in wound healing and repair [13]. The dressings can be 100% collagen or combined with other products, such as alginates [15]. They provide a high level of absorption while keeping the wound bed moist and are easily removed [15]. For wounds with very little drainage, collagen gel can be applied in a layer one-quarter inch thick [13]. Collagen used in most wound dressings is derived from cowhide [15]. Therefore, it should not be used in patients who are allergic to bovine products [15].

Electrical stimulation is effective in increasing the healing rate of chronic pressure injuries [61]. It is generally indicated for persons with spinal cord instability and difficult-to-heal injuries. In one study of individuals with spinal cord injury and pressure injuries, low-frequency pulsed current (i.e., alternating current) was compared to direct current and control groups [62,63]. Researchers found that injuries treated with electrical stimulation healed faster compared to controls and to standard treatment. Electrical stimulation is recommended by the ACP as adjunctive therapy in patients with pressure injuries to accelerate wound healing [64,65].

This therapy consists of the placement of a high-voltage, pulsed electrical current onto the wound bed (direct) or near the wound (induced), usually once daily for several weeks. The electrical settings (e.g., the polarity, amplitude and voltage, amperage) are established according to wound and patient characteristics. The Institute for Clinical Systems Improvement 2012 guideline recommends considering the use of direct contact electrical stimulation in the management of recalcitrant stage 2 as well as stage 3 and 4 pressure injuries to facilitate wound healing [61]. Although electrical stimulation is used for the treatment of pressure ulcers, a 2020 Cochrane review found that available evidence is insufficient to support its widespread use apart from its use in research [66].

Fluids taken from chronic pressure injuries have a significant degradation of growth factor activity compared to acute wounds [67,68,69]. The application of topical gels containing platelet-derived growth factor can increase fibroblast activity and accelerate healing for chronic wounds [68,70]. The application of 100 mcg/g becaplermin gel once daily has been found to increase the incidence of complete healing compared to placebo [71].

The use of hyperbaric oxygen in the treatment of pressure injuries is controversial. Hyperbaric oxygen therapy consists of 100% oxygen administered at a pressure of 2 to 3 atmosphere for a duration of one to two hours daily. This results in hemoglobin becoming saturated and oxygen spilling into the blood plasma. The vasoconstrictive effects result in reduction of edema in compromised flaps, pressure injuries, burns, and crush injuries. Improved oxygenation causes increased fibroblast activity and antimicrobial activity, with the stimulation of the phagocytic activity of the white blood cells [72]. It has been hypothesized that hyperbaric oxygen therapy could promote healing of pressure injuries; however, more research is necessary to evaluate the risks, benefits, and associated costs [73].

Studies have shown that pressure injuries treated with radiant heat heal faster and result in shrinking of the injury [74]. Because this requires special equipment and trained clinicians, however, it is not yet widely used.

Theoretically, therapeutic ultrasound can be beneficial in healing pressure injuries based on both thermal and non-thermal effects (Table 5). The NPIAP recommends that high-frequency ultrasound be considered as an adjunct for the treatment of infected pressure injuries. However, both a meta-analysis and a comprehensive review of available data on the efficacy of ultrasound in the treatment of pressure injuries were inconclusive [75,76].

Pulsed electromagnetic field therapy can be an alternative treatment when pressure injuries are resistant to conventional therapies. This technique has been found to increase synthesis of DNA, improve revascularization, reduce bacterial growth, and increase neurotransmitter receptor and hormone receptor activity [77,78,79]. Researchers have demonstrated complete healing within a few weeks of initiating this treatment in patients with stage 3 and 4 injuries [80,81].

Negative pressure wound therapy is useful for advanced (stage 3 or 4) pressure injuries and poorly healing wounds with copious drainage. In general, it consists of a foam sponge dressing placed into the injury and connected by a drainage tube to a pump that exerts intermittent or continuous negative pressure on the wound bed. The negative pressure reduces edema and facilitates removal of excessive fluid and infectious debris from the bed of the injury. The effect is to increase local blood flow, promote granulation tissue, and speed wound healing

Negative pressure wound therapy has cost-saving advantages. It reduces the frequency of dressing change to three or less times a week, decreases nursing time and cost, and often permits earlier discharge and follow-up care in the ambulatory setting. Patients experience less of the pain associated with manipulation of the wound.

When considering negative pressure therapy for wound management, patient selection and plan of care should be made with caution and always in consultation with wound care specialists and/or experienced surgeons. Adverse events, such as serious bleeding and unrecognized deep infection, have been reported [82]. Moreover, this modality is not effective for injuries and wounds with necrotic tissue or malignancy in the margins.

At this stage, injuries often heal with proper care and treatment, but some will deteriorate further. The aim is to quantify the extent of the wound, increase blood circulation, and prevent further breakdown of skin. Treatment should focus on:

The aim for patients with stage 1 pressure injuries is to prevent further deterioration of the injury and improve circulation. The same treatment plan implemented for suspected deep tissue injury should be the starting point. Skin should be cleansed and lightly moisturized. Massage on the affected area is contraindicated as it can lead to further tissue injury. If indicated, hydrocolloid dressings and transparent film dressings should be used. Surgical treatment and debridement are not indicated.

Promoting healing is the main goal for stage 2 injuries, with a focus on prevention of progression to full-thickness injury. Beginning with the same treatment plan implemented for previous stages, steps should be added to protect against infection. An appropriate dressing should be applied to promote healing and keep the wound bed clean. The skin is fragile at this stage, so adhesives should be avoided. Nutritional status should be re-evaluated, and supplements added, if necessary. Surgical treatment is not indicated, and debridement is rarely necessary.

Maintenance of a clean, moist wound bed to prevent infection and promote healthy granulation tissue is the prime goal in the treatment of stage 3 injuries. Infection impedes healing and may lead to complications such as sepsis and osteomyelitis. Careful assessment and follow-up are important at this stage; at the first clinical sign of infection, deep wound cultures should be obtained and appropriate antimicrobial therapy initiated promptly.

Along with the measures described for the previous stages, debridement should be carried out if indicated. Autolytic or enzymatic debridement is recommended for stage 3 injuries with light-to-moderate exudate; surgical debridement is necessary if there is necrotic tissue and infection [83].

Wound gels may be used if the injury is partially or completely covered with necrotic tissue. Foam dressings and cavity fillers are indicated if the injury bed is free of necrotic tissue and debris. Alginate dressings can also be applied if the wound has excessive exudates.

Stage 3 injuries usually heal spontaneously with appropriate cleaning and dressing. However, when treated conservatively, they have a recurrence rate of between 32% and 77% [84]. Surgical management can reduce the rate of recurrence in some patients [84]. However, according to a Cochrane review, randomized evidence neither supports nor refutes the role of surgery in the management of stage 2 or above pressure injuries [85].

For patients with stage 4 injuries, the focus of treatment is to provide an environment for new tissue growth. This can also involve removal of necrotic tissue and drainage reduction.

First, the injury should be assessed for bone involvement and signs of infection. If indicated, antibiotics should be started. Surgical management is often indicated in stage 4 injuries to address or prevent complications due to the large size of the wound. Debridement is often necessary to remove necrotic tissue.

When treating patients with unstageable pressure injury, practitioners should focus on providing a moist environment and preventing further deterioration. Injury stage should be reassessed when the base is visible and the treatment plan adjusted accordingly. The wound should be assessed for signs of infection, and antibiotics may be indicated. As with all stages, pain management and patient comfort should be ensured.

The wound should be debrided of nonviable tissue in the wound bed. One exception is the eschar on the heels, which should never be debrided unless infected.

Documentation of location is paramount for proper monitoring of pressure injuries. Placement can affect healing and treatment decisions. Wounds that may be exposed to urine or feces should be provided special attention and care, and peripheral wounds may require more time to resolve.

The location of the wound should be stated in a manner that is clearly understood, such as the sacrum or right or left ischium [49]. Anatomical markings should be used when possible.

Accurate measurement of the wound is probably the most important feature of wound assessment [35]. It provides information on the initial size and progression or non-progression of healing, allowing for valuable feedback on the effectiveness of clinical interventions [15]. Decreasing wound size is generally regarded as a sign of wound healing, but an increase in wound area is not necessarily indicative of deterioration [15].

Wounds should always be measured in centimeters, using a plastic or paper ruler. Wound length is measured from head to toe; width is measured from hip to hip [13]. The depth of the wound can be obtained by gently inserting a sterile cotton-tipped applicator into the wound bed and marking it at skin level. The applicator is then measured using a metric ruler [13].

Sinus tracts and undermining impair healing, and it is important to immediately identify their presence. A sinus tract is a tunnel that extends from any part of the wound and can bore through subcutaneous tissue and muscle. This tunnel creates dead space, which can result in abscess formation and further impede the healing process. A sinus tract can be measured using a sterile cotton swab.

Undermining is defined as destruction of the tissue under the skin around the edges of the wound. This frequently occurs in pressure injuries that have been subjected to shear force as well as pressure. It is important to document the location and extent of undermining.

The easiest way to measure and describe undermining is by using the face of the clock [15]. With the patient's head representing 12 o'clock, sweep the area of undermining or probe the tunneling to ascertain the depth. For example, undermining along the right border would be recorded as extending from 1 o'clock to 5 o'clock with a depth of 4 cm. It is important to check around the entire perimeter of the wound, as undermining can occur in more than one location.

It is also vital to assess and document the appearance of the wound bed (Table 7). If the wound bed has a mixture of tissue in it, this should be documented by an approximate percentage (e.g., 75% granulation tissue and 25% slough). Granulation results in "beefy" red tissue consisting of new capillaries, fibroblasts, and collagen fibers with a shiny, moist granular appearance. Grey or purple granulation is a sign of poor vascularization. Granulation present in the wound denotes healing.

Necrosis is gray, brown, or black unviable tissue that usually must be removed in order for healing to take place. Eschars are typically gray to black and dry or leathery in appearance. Slough tissue is yellow/white to gray in color. It may be stringy or thick and appear as a layer over the wound bed. Epithelial tissue will often begin to grow in from the edges over the wound surface. This tissue is generally pink and shiny. As a quick reference color guide, red is associated with normal healing, yellow indicates slough or dead tissue, and black is necrosis.

Exudates are an indication of inflammation in the wound. The presence of large amount of exudate can delay healing and increase the risk of infection. As such, this factor has a significant impact on treatment decisions, particularly dressing type. The amount and quality of any exudates should be noted. Amount may be denoted as:

The quality of the exudates may be described as [88]:

Malodor with purulent exudates suggests mixed infection often combined with ischemic necrosis. However, the majority of wounds (even those free of infection) do have some odor. As previously discussed, gram-negative and gram-positive infections have distinct odors. If present, an injury's odor (quality and strength) should be documented.

In addition to fluid and metabolic resuscitation, treatment of sepsis requires parenteral antibiotics and, when necessary, surgical debridement and/or drainage of deep tissue suppurative fluid collections. Vasopressors and inotropic therapy may be necessary to restore adequate blood pressure and perfusion. The initial choice of antibiotics will depend on the most likely pathogens associated with the source of infection as well as the prevalent micro-organisms in the local community and health facility. The anticipated susceptibility profile of prevalent local pathogens and the ability of the antibiotic to penetrate to the source of the infection should also be considered. A combination of drugs with activity against all likely pathogens should be administered initially, but the regimen should be reassessed in light of culture results, the goal being to identify a single, narrow-spectrum antibiotic that will best control the infection [97]. A common approach is to initiate empiric therapy with a carbapenem or extended-spectrum penicillin/beta-lactamase inhibitor (e.g., ticarcillin/tazobactam) to cover gram-negative enteric bacilli, anaerobes, and Pseudomonas, often in combination with vancomycin to cover Staphylococcus aureus pending culture results.

Proper support for organ failure is indicated for patients with severe sepsis, and sedation, mechanical ventilation, and analgesia are often required in late-stage disease. Adequate nutrition (usually administered parenterally) and glucose control are necessary. The patient should be stabilized prior to restarting injury treatments.

In the presence of underlying osteomyelitis, satisfactory healing of the pressure injury is usually not possible unless the bone infection is eradicated. This requires parenteral followed by oral antimicrobial therapy for a minimum of six to eight weeks, combined, if necessary, with surgical debridement of necrotic bone. Any surgical approach to (presumed) infected bone, whether needle aspiration, biopsy, or debridement, should include submission of bone specimens for culture.

In the surgical management of stage 4 injury cases with little or no overt clinical or radiographic sign of bone infection, submission of bone specimens for culture is useful for identifying early, limited osteomyelitis and thus the need for post-operative antimicrobial treatment. Examples are cases requiring partial ostectomy or ablative surgery of stage 4 injuries with resection of bone from the base of the injury crater.

The medical chart should be examined to determine the level of care planning, assessment, and interventions. Wound neglect is usually associated with improper treatment, inadequate nutrition, and/or poor survey results.

Family diaries, stage surveys, in-service records, complaint files, minutes of quality assurance meetings, and photographs can also be helpful for identification of deviations from standard injury care.

Documentation of pressure injury care must be timely and detailed. Regular and consistent descriptions of the injury should be documented, as should responses to treatment. Improper, irregular, or "late entries" are absolutely impermissible and unacceptable.

In patients with multiple injuries, progression of each wound should be documented and tracked. With the growing awareness of the possibility of litigation in wound care, many facilities have instigated a policy of photo documentation. Wounds present on admission are photographed, and some facilities require serial photographs to track wound progress and status at the time of discharge. Signed consent is required before wound photographs can be taken, and in most instances, the photographs become a permanent part of the patient's medical record.

It has been found that 30% to 85% of nursing home residents are malnourished and 30% to 50% are considered underweight [112]. Pressure injury treatment requires proper nutritional assessment and intervention during every stage. Weight loss, lab results, protein consumption, and vitamin levels should be documented, as should attempts to address abnormalities. If tube feeding is indicated, it should be discussed with the family prior to initiation.

Treatment administration records should be examined to ensure that treatments were carried out per orders. Documentation should also include staffing records and time-sheets. Dates and times should always be included.

Minimum data sets are required for all residents of skilled nursing facilities. Improper and inaccurate entries in the minimum data sets indicate a facility with under-staffing and disorganized structure providing poor treatment to the resident. Scrutiny of this document can lead to litigation.