Comprehensive Guide to Pressure Injuries

Nutritional status is closely related to pressure injuries (PIs), as being at risk for PIs is often associated with malnutrition or the risk of malnutrition. Nutrition interventions are crucial in the prevention and treatment of PIs because malnutrition is a recognized risk factor for both the development and severity of PIs.

One of the primary markers of declining nutritional status is unintended weight loss. However, malnutrition can occur in individuals regardless of their weight profile.

It is recommended to conduct nutrition screening for individuals at risk of a pressure injury as a good practice. Additionally, a comprehensive nutrition assessment should be performed for those screened to be at risk of malnutrition, which will help in developing an individualized nutrition care plan.

Nutritional status is influenced by the individual's clinical profile and social determinants of health. A holistic approach to screening, assessment, and care planning is essential to effectively address nutrition.

Pressure ulcers/injuries are localized damage to the skin and/or underlying tissue, usually over bony prominences or related to medical devices, resulting from prolonged pressure or pressure combined with shear. They occur due to prolonged mechanical loads on the skin and underlying soft tissues, leading to tissue deformation, which can occlude blood and lymph vessels, causing necrotic and apoptotic cell death. Additionally, tissue deformation can directly impair essential cellular functions.

The preferred term for pressure ulcers in English-speaking countries, including Australia and the USA, is 'pressure injury' (PI).

Intrinsic factors such as age, nutrition, skin status (history of wounds), and other comorbidities can influence the relationship between pressure, tissue deformation, and the likelihood of tissue compromise.

The sigmoid curve represents the relationship between pressure/tissue deformation, time, and tissue tolerance to load, providing important insights into how prolonged pressure can lead to tissue damage. This relationship may vary based on intrinsic factors.

Nutrition screening aims to identify individuals at nutritional risk, which is associated with a reduction in pressure injury (Pl) rates and decreased hospital length of stay. It allows for faster implementation of nutritional interventions for those identified as at risk.

Any member of the healthcare team can complete nutrition screening, although it is suggested that they complete education and training before conducting the screening.

Individuals screened as being at risk of malnutrition should be referred to a registered dietitian/nutritionist or an interprofessional nutrition team for a comprehensive nutrition assessment.

A comprehensive nutrition assessment involves a systematic process of collecting, verifying, interpreting, and documenting data related to the individual's nutritional status. It should also include developing a nutrition management plan tailored to the individual's needs.

Signs and symptoms of dehydration should be monitored, including vital signs, thirst, urine output, elevated serum sodium, calculated serum osmolality, skin turgor, and dryness, especially when using certain support surfaces that can increase insensible fluid loss.

The four main pathophysiological theories are:

1. Localized ischemia - Reduced blood flow and tissue perfusion leading to cell death due to lack of oxygen and nutrient supply.
2. Direct cell deformation damage - Sustained deformation of cells causing direct damage and death.
3. Reperfusion injury - Restoration of blood flow after ischemia leading to inflammation and tissue injury.
4. Impaired lymphatic drainage - Mechanical loading impairing lymph flow, reducing clearance of waste products in soft tissues.

Localized ischemia affects tissue types differently:

• Muscle tissue is much more susceptible to ischemia compared to skin.
• Skin is more resistant to reduced perfusion.
  The degree of ischemia also depends on anatomical location and loading frequency during cyclical loading.

Direct cell deformation damage involves:

• Changes in the cytoskeleton.
• Increased permeability of cell membranes beyond normal thresholds.
  This damage can occur rapidly, within minutes, especially when the deformation exceeds individual damage thresholds.

Reperfusion injury occurs when tissues are relieved after periods of loading and ischemia, leading to a reactive hyperemic response that restores oxygen and carbon dioxide levels.

• This restoration can release accumulated waste products, including reactive oxygen species, causing inflammation.
• The magnitude and duration of loading influence the extent of reperfusion injury.

Impaired lymphatic function may lead to:

• Reduced clearance of waste products in soft tissues due to sustained mechanical loading.
• Lymphatic vessels are occluded at lower levels of tissue deformation compared to blood vessels, affecting local edema clearance and inflammatory byproducts.
• The relative importance of lymphatic function in the etiology of pressure injuries is less well understood.

Regular monitoring and evaluation of nutrition status is crucial to adjust the nutrition care plan as needed, ensuring that the individual's nutritional needs are met effectively. This can be done through methods such as weekly weight recordings or according to local policy.

A nutrition plan should be developed by a trained healthcare team member in consultation with the individual and their informal carer. It must align with care goals, priorities, cultural, religious, and personal preferences, as well as dietary practices.

A comprehensive assessment should include an evaluation of hydration status, as individuals with darker skin tones are at risk of dry skin and pruritus. Dry skin alone should not be used as a marker for dehydration without other indicators.

Nutrition assessment should be facilitated at least weekly, and it is important to measure and document body weight, height/length, and head circumference in infants under 3 years. Z-scores for BMI for age should be used to screen for those at extremes, and growth patterns should be monitored using anthropometric measurements and growth charts.

Some widely used nutrition screening tools for adults include:

1. Canadian Nutrition Screening Tool (CNST)
2. Malnutrition Screening Tool (MST)
3. Mini Nutritional Assessment (MNA)
4. Malnutrition Universal Screening Tool (MUST)
5. Nutrition Risk Screening (NRS)
6. Rapid Screen
7. Short Nutrition Assessment Questionnaire (SNAQ)
8. Seniors in the Community: Risk Evaluation for Eating and Nutrition (SCREEN-II AB)
9. Subjective Global Assessment Tool

Recommended nutrition screening tools for children include:

1. Paediatric Nutrition Screening Tool (PNST)
2. Paediatric Yorkhill Malnutrition Score (PYMS)
3. Screening Tool for the Assessment of Malnutrition in Pediatrics (STAMP)
4. Screening Tool for the Risk of Impaired Nutritional Status and Growth (STRONGkids)
5. Subjective Global Nutritional Assessment for Children (SGNA)

The two main damage mechanisms are the slow damage mechanism and the fast damage mechanism. The slow mechanism involves smaller deformations leading to impaired perfusion and lymph flow, resulting in ischemia and tissue injury. The fast mechanism involves larger deformations causing direct cell deformation, also leading to tissue injury.

Ischemia and direct cell damage are critical in pressure injury development. Ischemia may take longer to induce pathological changes, while direct cell damage occurs quickly, especially in muscle tissue, leading to deep tissue injuries. Both pathways interact and contribute to the complexity of pressure injury development.

Factors include:

1. Anatomical location
2. Morphology (e.g., bone geometry, tissue thickness)
3. Properties of soft and stiff tissues
4. Degree of tissue deformation
5. Skin microclimate
6. Individual tolerance and repair capacity

These factors influence the likelihood of developing deeper or more superficial pressure injuries.

The likelihood of pressure injury development increases with the magnitude and duration of soft tissue loading. Direct deformation damage may occur quickly, while perfusion-related damage may take longer to cause local cell death and necrosis.

A comprehensive nutrition assessment should include the following components:

1. Food history: Adequacy of nutritional intake and weight history.
2. Anthropometric measures: Height, weight, and body mass index (BMI).
3. Clinical condition: Physical and mental health, cognition, and relevant medical tests/procedures.
4. Nutrition-focused physical assessment: Evaluation of muscle wasting, edema, hydration status, micronutrient deficiencies, and functional status (e.g., handgrip).
5. Ability to swallow, eat, and drink independently.
6. Personal, family, cultural, ethnic, and religious dietary practices and preferences.
7. Biochemical data evaluation: Consider electrolytes, creatinine, serum osmolarity, and blood urea nitrogen to assess hydration status.
8. C-reactive protein (CRP): To assess the potential impact of inflammation on micronutrients.
9. Avoid reliance on serum protein levels: As they may be affected by various factors, reducing their utility in assessing nutritional status.

Individuals at risk of pressure injuries should be encouraged to:

• Consume a balanced diet that includes nutrient-dense foods.
• Maintain adequate hydration.

Supporting information indicates that for most individuals, nutritional requirements can typically be met with a healthy oral diet, tailored to individual circumstances such as medical conditions, lifestyle, and demographics.

Water is essential for:

• Transporting vitamins, minerals, glucose, and other nutrients through the body.
• Eliminating waste products from the body.

In healthy individuals who are adequately hydrated, water released from food and metabolism accounts for 20% or more of total water intake.

The following organizations have developed dietary/nutrition guidelines:

• National Academies of Sciences, Engineering and Medicine (NASEM)
• Academy of Nutrition and Dietetics
• European Food Safety Authority
• European Society for Clinical Nutrition and Metabolism (ESPEN)
• American Society for Parenteral and Enteral Nutrition (ASPEN)
• Australian National Health and Medical Research Council (NHMRC)
• New Zealand Ministry of Health
• PROT-AGE Study Group
• Paralyzed Veterans of America (PVA)

The Reswick and Rogers pressure-time curve is significant as it provides a framework for understanding the relationship between pressure duration and the risk of developing pressure ulcers. It helps in identifying critical thresholds of pressure and time that can lead to tissue damage, thereby guiding prevention strategies.

The main factors contributing to the etiology of pressure ulcers include:

1. Pressure - Sustained pressure on soft tissues can lead to ischemia and tissue damage.
2. Shear - The sliding motion between skin and underlying tissues can exacerbate injury.
3. Microclimate - The moisture and temperature around the skin can affect tissue viability.
4. Tissue perfusion - Impaired blood flow can lead to tissue hypoxia and increase ulcer risk.
5. Individual tolerance - Variability in individual skin and tissue responses to mechanical loading.

Ischemia-reperfusion injury relates to chronic pressure ulcer formation by causing damage to tissues when blood supply is restored after a period of ischemia. This process can lead to inflammation and further tissue injury, contributing to the development of pressure ulcers, especially in individuals with compromised blood flow.

Lymphatic dysfunction plays a critical role in the etiology of pressure ulcers by impairing fluid drainage from compressed tissues. This can lead to increased interstitial fluid pressure, tissue edema, and further compromise of blood flow, ultimately contributing to tissue damage and ulcer formation.

Local cooling has implications for pressure ulcer prevention as it can enhance skin perfusion response to pressure. By reducing tissue temperature, local cooling may help maintain blood flow and oxygen delivery to the skin, potentially reducing the risk of pressure ulcer development during prolonged loading.

• Recognize challenges in implementation, particularly in clinical and geographic contexts where access to nutrient-dense foods is limited.
• Provide mealtime assistance to facilitate optimal nutrition and fluid intake.
• Implement standard nutrition care strategies to promote optimal intake, such as facilitating access to nutrient-dense foods, suggesting smaller, frequent meals, creating a positive mealtime environment, and addressing functional or cognitive deficits that impact dietary intake.

Dietary restrictions should be modified or liberalized in consultation with a medical professional, and wherever possible, managed by a registered dietitian/nutritionist.

In healthy individuals, water/fluid intake should be approximately 30 mL/kg body weight/day or 1 mL/kilocalories/day. However, fluid intake may need to be adjusted based on individual health conditions such as heart or renal failure, elevated temperature, vomiting, or high protein intake.

Nutritional supplementation may include food fortifiers, enhanced foods, or nutritional supplements that supply protein, carbohydrates, fats, vitamins, and minerals, especially when oral dietary intake is inadequate or nutritional deficiencies are suspected or confirmed.

The guideline suggests implementing nutritional supplementation for individuals at risk of pressure injuries who are identified as malnourished or at risk of malnutrition when their nutritional needs are not met by usual dietary intake.

The relative effect is 24 fewer pressure injuries per 1,000 individuals treated, with a confidence interval of 0.61-0.91. However, there is very little confidence that this effect estimate represents a true effect due to risk of bias and indirectness of the evidence.

1. Increased and optimized oral intake
2. Fortified foods
3. Oral supplements
4. Enteral tube feeding
5. Parenteral supplementation

Nutritional interventions should be based on the individual's overall nutritional needs, considering their clinical condition and tolerance, rather than any single dietary component in isolation.

Challenges include resource availability, the individual's acceptance of nutritional supplements, and potential financial or logistical barriers in certain care settings.

1. Ensure sufficient carbohydrate and high levels of protein
2. Adequate levels of vitamin C, zinc, vitamin A, iron, and minerals
3. Base nutrition requirements on normal growth and development, and adjust based on laboratory measurements
4. Regularly re-evaluate nutrition requirements and mode of delivery

It is suggested to implement protein supplementation for individuals at risk of pressure injuries who have been identified as malnourished or at risk of malnutrition. This is a conditional recommendation with very low certainty of evidence.

The meta-analysis showed that protein supplementation was associated with a non-significant lower rate of pressure injury occurrence, with a relative risk (RR) of 0.75. This translated to a difference of seven fewer pressure injuries per 1,000 individuals treated, but the evidence was downgraded due to risk of bias and imprecision.

Implementation considerations include:

1. Consulting a registered dietitian/nutritionist for appropriate supplementation.
2. Recognizing challenges such as resource availability and individual acceptance of protein supplements.
3. Calculating macronutrient requirements based on dietary/nutrition guidelines relevant to the individual's profile.
4. Considering the adequacy of caloric intake when assessing the need for protein supplementation.
5. Assessing renal function to ensure high protein levels are appropriate and reassessing as clinical conditions change.

Dietary/nutrition guidelines suggest supplementing protein at a rate of 1.2-1.5 g/kg body weight/day for older adults.

Dietary/nutrition guidelines suggest supplementing protein at a rate of 1.2-2.0 g/kg actual body weight/day for critically ill individuals.

For individuals with obesity, it is suggested to increase protein supplementation to 2.0 g/kg ideal body weight/day for BMI >30 to 40, and to 2.5 g/kg ideal body weight/day for BMI >40.

For individuals with spinal cord injury, it is important to review and follow dietary/nutrition guidelines, as this population experiences injury-induced changes to body composition and metabolism that influence dietary requirements, which may change throughout the stages of disease.

Carbohydrate-based energy and micronutrient supplementation should be reserved for individuals with known malnutrition or micronutrient deficiencies, in addition to meeting their protein needs.

The meta-analysis showed that carbohydrate-based energy, protein, and micronutrient supplementation was associated with a non-significant lower rate of pressure injury occurrence, but there is limited confidence in the effect estimate due to risk of bias in the studies.

The cost-effectiveness, feasibility, and acceptability of providing supplementation vary depending on the individual, healthcare system, geographic and clinical context, and the ability to access supplementation and support systems like screening for nutritional deficits.

For individuals who are malnourished, underweight, have significant unintended weight loss, inadequate caloric intake, critical medical conditions, or known vitamin/mineral deficiencies, clinical benefits might be achieved from energy-based supplementation, although the impact on preventing pressure injuries is uncertain.

Use indirect calorimetry to estimate resting energy expenditure. If unavailable, use an appropriate predictive equation or a simplistic weight-based equation (e.g., 25-30 kcal/kg/day), noting that these methods are less accurate than indirect calorimetry.

The guideline recommends against tube feeding for the specific purpose of preventing pressure injuries in individuals with or at risk of malnutrition and at pressure injury risk, based on very low certainty of evidence.

Any decision to implement tube feeding should be preceded by a comprehensive, multidisciplinary assessment of goals of care, benefits, risks, and preferences related to the individual.

The meta-analysis showed that tube feeding was associated with a statistically significant higher occurrence of pressure injuries (RR 1.50), with serious adverse events occurring more often with tube feeding compared to oral diet.

The Guideline Governance Group considered the required resources, feasibility, acceptability, and the ethical philosophy of the healthcare setting, as well as the geographic and clinical context when making recommendations about tube feeding.

• Discuss the benefits and harms of enteral or parenteral feeding with individuals and their informal carers.
• Balance patient autonomy, beneficence, nonmaleficence, and justice.
• Enteral feeding may be implemented for individuals who cannot meet their nutritional requirements through oral intake when it aligns with their care goals.
• Administer enteral feeding by qualified professionals using a monitoring protocol that includes routine assessments.
• Evaluate tolerance of enteral feeding daily through physical examinations and gastrointestinal signs.
• Be aware of the risk of device-related pressure injuries and mucosal membrane injuries during tube feeding.

• Prioritize comfort and symptom control; supplemental nutrition should be provided if it enhances comfort and is agreed upon by the individual and healthcare team.
• If supplemental nutrition increases discomfort and prognosis is poor, it should not be prioritized.
• Strive to maintain adequate nutrition and hydration compatible with the individual's condition and preferences.
• Ensure good oral care, including lip balm to prevent lip cracking.

Nutritional intervention can lead to improved patient outcomes, reduced complications, and decreased healthcare costs. It addresses the underlying malnutrition, which can enhance recovery and reduce the length of hospital stays.

Malnutrition can significantly increase the risk of developing pressure ulcers and worsen their severity. Nutritional deficiencies impair skin integrity and healing processes, making older patients more vulnerable to these injuries.

Nutrition is critical in wound care as it supports the healing process, enhances immune function, and reduces the risk of infection. Adequate nutritional intake is essential for tissue repair and recovery from wounds.

The characteristics include unintentional weight loss, inadequate energy intake, loss of muscle mass, loss of subcutaneous fat, and fluid accumulation that may obscure the true body weight. These factors help in assessing malnutrition in adults.

The Braden Scale is a tool used to assess a patient's risk of developing pressure ulcers, which includes evaluating nutritional status as a key factor. It helps healthcare providers identify patients who may benefit from nutritional interventions to prevent pressure injuries.

The guidelines emphasize the importance of individualized nutrition support therapy, assessing nutritional needs based on clinical status, and monitoring for efficacy and safety. They recommend early initiation of nutrition support, preferably within 24-48 hours of admission, and suggest using enteral nutrition as the first choice when feasible.

Nutritional screening tools are essential for identifying at-risk children, ensuring timely intervention, and improving clinical outcomes. They help in assessing nutritional status and guiding appropriate nutritional support to enhance recovery and prevent complications.

Nutrition is critical for maintaining skin integrity and promoting healing of pressure ulcers in chronically ill children. Adequate intake of proteins, vitamins, and minerals supports cellular repair, immune function, and overall health, which are vital for wound healing.

The Norwegian Directorate of Health recommends the Malnutrition Screening Tool (MST) for all adults to identify those at risk of malnutrition, facilitating early intervention and management of nutritional needs.

The Paediatric Yorkhill Malnutrition Score (PYMS) has shown good performance in identifying malnutrition in hospitalized children, demonstrating reliability and validity in clinical settings, which aids in appropriate nutritional management.

The absence of oral nutritional support in low food intake inpatients is associated with an increased risk of hospital-acquired pressure injury, as indicated by the study by Papier et al. (2022).

The study by López et al. (2019) explores the relationship between pressure ulcer risk as assessed by the Norton Scale and the 'Eating/Drinking' need assessment, suggesting that nutritional needs are critical in evaluating pressure ulcer risk.

The study by Botigue et al. (2019) highlights the prevalence and risk factors associated with low fluid intake in institutionalized older residents, which can contribute to various health complications, including pressure injuries.

Covinsky et al. (2002) discuss that serum albumin concentration and clinical assessments of nutritional status in hospitalized older people represent different aspects of nutritional health, indicating the complexity of assessing malnutrition risk.

According to Cotogni et al. (2021), nutritional support is crucial for cancer patients in palliative care, as it can improve quality of life and potentially enhance treatment outcomes.

The PROT-AGE Study Group provides evidence-based recommendations emphasizing the importance of adequate protein intake for older adults to maintain muscle mass and overall health, as detailed by Bauer et al. (2013).

The study by Bourdel-Marchasson et al. (2000) demonstrated that oral nutritional supplementation can have positive effects on the nutritional status and recovery of critically ill older inpatients.

Delmi et al. (1990) focused on the effects of dietary supplementation in elderly patients with fractured neck of the femur, highlighting its potential benefits in recovery and nutritional status.

The FOOD trial found that routine oral nutritional supplementation for stroke patients in the hospital improved their nutritional intake and potentially their recovery outcomes.

Hartgrink et al. (1998) investigated the relationship between pressure sores and tube feeding in patients with a fracture of the hip, concluding that nutritional support is crucial in preventing pressure sores.

Tkatch et al. (1992) observed that oral protein supplementation in elderly patients with hip fractures led to improved recovery outcomes and nutritional status.

Wyers et al. (2018) found that nutritional intervention significantly improved recovery outcomes in elderly patients after hip fracture, emphasizing the importance of nutrition in rehabilitation.

Houwing et al. (2003) assessed the effect of nutritional supplementation on the prevention of pressure ulcers in hip-fracture patients, finding it beneficial in reducing the incidence of pressure ulcers.

Olofsson et al. (2007) focused on addressing malnutrition in hip fracture patients through an intervention study, demonstrating the effectiveness of nutritional support in this population.

Chen et al. (2023) revealed that oral nutritional supplementation positively affected outcomes in older adults with hip fractures and identified factors influencing compliance with supplementation.

Botella-Carretero et al. (2010) found that perioperative oral nutritional supplements improved recovery and nutritional status in normally or mildly undernourished geriatric patients undergoing surgery for hip fracture.

The study compares survival, pneumonia, and hospitalization in patients with advanced dementia and dysphagia receiving either oral or enteral nutrition.

The study finds that percutaneous endoscopic gastrostomy does not prolong survival in patients with dementia.

Hypoalbuminemia is identified as a poor predictor of survival after percutaneous endoscopic gastrostomy in elderly patients with dementia.

The study discusses the risk factors and impact on survival of feeding tube placement in nursing home residents with severe cognitive impairment.

Pressure injuries, also known as pressure ulcers or bedsores, are localized damage to the skin and underlying tissue, typically over bony prominences, caused by prolonged pressure or pressure in combination with shear. They can present as intact skin or open ulcers and may be painful.

Key characteristics of pressure injuries include:

• Location: Commonly found over bony prominences such as the sacrum, heels, elbows, and hips.
• Etiology: Caused by sustained pressure, shear forces, friction, and moisture.
• Presentation: Ranges from non-blanchable redness of intact skin to deep tissue damage exposing muscle or bone.

The concept of pressure injuries has been recognized for centuries, with systematic study beginning in the 19th and 20th centuries. Florence Nightingale emphasized hygiene and repositioning during the Crimean War, while advances in medical technology and staging systems in the 20th century improved understanding and management.

Pressure injuries are significant in healthcare due to their prevalence, impact on patient outcomes, and financial burden. They are considered a marker of quality care, with approximately 2.5 million patients developing them annually in the U.S., costing the healthcare system an estimated $9.1–$11.6 billion.

Intrinsic risk factors include:

1. Immobility: Prolonged pressure on specific areas.
2. Age: Thinner skin and reduced vascularity in the elderly.
3. Chronic Conditions: Diseases impairing circulation and healing.
4. Malnutrition: Weakens skin integrity.
5. Neurological Impairments: Reduced sensation.
6. Incontinence: Increases skin moisture and breakdown risk.

The NPIAP staging system includes:

1. Stage 1: Non-blanchable erythema of intact skin.
2. Stage 2: Partial-thickness skin loss with exposed dermis.
3. Stage 3: Full-thickness skin loss without exposure of muscle or bone.
4. Stage 4: Full-thickness skin and tissue loss with exposure of muscle, tendon, or bone.
5. Unstageable: Obscured full-thickness skin and tissue loss.
6. Deep Tissue Injury (DTI): Persistent non-blanchable deep red, maroon, or purple discoloration.

The Braden Scale is a risk assessment tool that evaluates six factors contributing to pressure injury risk:

1. Sensory Perception
2. Moisture
3. Activity
4. Mobility
5. Nutrition
6. Friction and Shear
   Scores range from 6 to 23, with a score of ≤18 indicating a higher risk of developing pressure injuries.

Evidence-based preventive strategies include:

1. Repositioning: Change position every 2 hours in bed and every 15-30 minutes in a chair.
2. Skin Care: Keep skin clean and dry, use moisture barriers.
3. Nutrition: Ensure adequate protein and calorie intake.
4. Hydration: Maintain proper fluid intake.
5. Mobility: Encourage physical activity and exercises.

Principles of wound care include:

1. Wound Assessment: Evaluate location, size, stage, exudate, tissue type, and surrounding skin.
2. Cleansing: Use appropriate solutions to clean the wound.
3. Dressing Selection: Choose dressings that maintain a moist environment and protect the wound.
4. Infection Control: Monitor for signs of infection and manage accordingly.
5. Pain Management: Address pain associated with the wound.