Understanding the link between pressure ulcers and nutrition can help clinicians improve resident care and promote healing.

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he development and healing of pressure ulcers are often described as a multifaceted process, influenced by factors ranging from health status and comorbidities to psychosocial issues and everything in between. Individuals with spinal-cord injury (SCI) have an incidence range of pressure ulcers (7.5–23.7%) similar to that of long-term care residents (7–23.9%).¹ Magee Rehabilitation Hospital (Philadelphia, Pa) provides acute rehabilitation for those with disabling injuries, including more than 300 admissions per year for individuals with new SCIs, and provides lifetime follow-up care for more than 2,500 individuals with chronic SCI. SCI is associated with an advanced aging process and an earlier onset of cardiovascular disease and diabetes, adding to the long list of pressure ulcer risks, such as immobility, incontinence, lack of sensation, decreased muscle mass, neurogenic skin changes, respiratory compromise, and malnutrition with obesity.²
       In any population, the effect of acute illness or trauma characteristically includes stress-induced catabolism in conjunction with a decrease in anabolic activity, setting the stage for major complications from loss of lean body mass (LBM). The association between protein-energy malnutrition (PEM) and pressure ulcers has been clearly demonstrated in both animal and human studies.^3–5 PEM, or the possibility of developing PEM, occurs in 30 to 50% of hospitalized patients.^6,7 The incidence can be as high as 65% for the hospitalized elderly, who may be undernourished at the time of admission or develop serious nutritional deficiencies during their hospital stay. Those with PEM and subsequent loss of LBM readily succumb to the effects of unrelieved pressure, especially if other pressure ulcer risks exist. Typically, these individuals with hospital-acquired malnutrition are the patients who are transferred to long-term care facilities or qualify for acute inpatient rehabilitation.
       The wide range of pressure ulcer risk factors (see Table 1)

Table 1

necessitates for the overall health of the individual, not just the wound, to be the focal point of care. Therefore, it is essential for all team members to understand the etiology of pressure ulcers and directly participate in care. It is also important to budget allowances for appropriate wound care interventions: no wrinkles in the bed sheets, cues for weight shifts during speech therapy, hydration breaks in physical/occupational therapy, words of encouragement from ancillary staff, maintenance of a clean and uncluttered environment, etc. When working in tandem, the efforts of the nurse and the dietitian can have a synergistic effect on improving patient outcomes, especially in the maintenance of skin integrity. To achieve this goal, it is essential for the nurse and the dietitian to have shared knowledge of PEM and pressure ulcers and of how this entwined relationship presents in high-risk patients.
       During metabolic stress, PEM occurs because of the increase in nutrient utilization and losses. The hallmark of PEM is involuntary weight loss (mainly loss of LBM) with subsequent depletion of functional protein stores. Progressive loss of LBM correlates with impaired immune and physical function, reducing one’s ability to perform self-pressure relief movements and respond to infection/stress. Protein stores are rapidly depleted to meet increased energy requirements. Protein requirements for wound healing can be as high as 1.5 to 2.5 g/kg to compensate for the burdens of increased protein synthesis and loss of amino acids being used for fuel.⁸
       Because of the stress-induced deficiency, the enteric and immune systems undergo major transformations, including changes in bowel function, immunosuppression, impaired wound healing, and skeletal-muscle wasting and weakness. Those with compromised gut function experience loss of appetite, diarrhea, decreased absorption of nutrients, and increased intestinal gut permeability. Increased intestinal permeability allows for microbial translocation and may lead to sepsis.⁹
       It is well understood that adequate amounts of macro- and micro-nutrients are needed to maintain and/or restore nutritional health. However, if bowel function (ie, absorption) is compromised, it should be anticipated that standard nutritional interventions will likely cause diarrhea. Logic dictates that you provide nutrients that the stressed bowel can utilize, thereby identifying and treating the source of the diarrhea. Early and appropriate nutritional intervention can help maintain gut integrity and prevent diarrhea (see Table 1 for triggers for early intervention). In a study by Meredith et al.¹⁰ comparing the incidence of tube-feeding-related diarrhea in 2 groups of ICU patients, the researchers found that 44% of the group on a standard, intact protein formula had diarrhea versus 0% in the group on a therapeutic, peptide formula.
       Unfortunately, some clinicians make the false assumption that tube-feeding-related diarrhea is acceptable and/or unavoidable and document as such (eg, “tolerating tube feeding with diarrhea”). A standard feeding with fiber is often recommended to correct diarrhea associated with PEM. In our experience, however, high-fiber feedings in malnourished patients increase the likelihood of bowel impaction. Clinically, this presents as watery diarrhea oozing past hard stool.
       While standard nutritional interventions are less expensive to purchase, the delay in appropriate nutritional care can further impair nutritional status and negate the effectiveness of even the best wound care. Under the business model of healthcare management, it makes the most “cents” to connect clinical dietitians with other clinical staff, as opposed to the food service staff. Traditional nutrition protocols, which are budgeted under food service, are driven by product cost, not clinical parameters. They require that the least costly interventions be used first, progressing to more expensive treatments as necessary. However, appropriate nutritional interventions are based on clinical assessments, which may entail higher upfront costs in order to improve patient outcomes while lowering overall expenses.
       From a food service perspective, the prices of specialized nutritional regimens exceed typical “tray cost” expectations, thereby restricting their use. A standard enteral formula costs approximately $5 to $7 a liter, the same as 3 meals per day, but is poorly tolerated by stressed patients. A therapeutic enteral formula costs approximately $20 to $25 a liter and is designed for good tolerance in metabolic stress. A contract food service company’s budget does not include the institution’s expense of tube-feeding-related diarrhea.
       Diarrhea can hinder nutrient uptake, accelerate nutrient losses, excoriate and macerate skin, contaminate existing wounds, and increase nursing care needs—but it does not impact a contract food management company’s bottom line. Without access to appropriate nutritional interventions, the dietitian’s ability to improve outcomes and reduce costs for the facility is limited. From a clinical/nursing perspective, the price difference between a standard versus a therapeutic nutritional regimen is insignificant when compared to other treatment modalities and the immense costs associated with uncorrected malnutrition.

Basic Nutritional Guidelines

       Adequate fluid intake is critical in both the prevention and treatment of pressure ulcers. High-protein intakes, fluid loss through wound drainage, and evaporative losses on air-fluidized beds contribute to higher fluid needs. Dehydration not only impairs skin integrity but can contribute to an individual’s pressure ulcer risk and can cause decreased blood flow, muscle fatigue (impaired ability to do self-pressure relief), diminished appetite, bowel impaction, etc. Enteral or intravenous (IV) access may be needed to meet fluid needs to ensure adequate hydration before increasing protein intake. If fluid needs cannot be met, a high-protein/nitrogen intervention is contraindicated, and wound healing may not be a reasonable goal.
       For our high-risk, tube-fed patients, a high-protein, peptide-based therapeutic formula is used first. The formula is designed to achieve good tolerance in the stressed patient by providing proteins as peptides and a high percent of fat (50%) as medium-chain triglycerides (MCT). The patient is transitioned to a standard formula (intact protein) in about 2 to 6 weeks as his or her nutritional status improves. Of course, all enteral feedings are administered via a closed system to minimize risk, intolerance, and costs.
       Our oral regimen for high-risk patients consists of 3 separate, sugar-free products: an arginine-glutamine combination, a powdered wound care vitamin-mineral supplement, and a complete protein source (either in liquid or powder form). All 3 products are mixed together in 8 ounces of water. The patient is given 1 or 2 servings a day. Additional vitamin and mineral or protein supplements are not needed. These products are classified as nutraceuticals and recommended by the dietitian (including the specific indication, dose, and duration), ordered by the physician, dispensed by the pharmacist, and administered by the nurse.
       The weekly cost of our protocols is $215 for the therapeutic enteral formulary (including bags) and $50 for the oral protein-vitamin-mineral regimen. The estimated weekly cost per patient to care for a full-thickness pressure ulcer is $850 to $1,450. The weekly cost of diarrhea remains questionable, but it can be expensive.
       The connection between PEM and pressure ulcers is clear: uncorrected malnutrition contributes to pressure ulcer development and can prevent an existing wound from healing. The triggers for intervention in pressure ulcer management are the same as those that signal the likelihood or presence of malnutrition. Therefore, nutritional interventions are geared to provide specific nutrients needed to stop the progress of malnutrition, support anabolism, prevent nutrient deficiencies, and maintain health. With good nursing care, the wound will then have a chance to heal.