Invited Commentary
Challenges in Nutrition, Pressure Ulcers, and Wound Healing
Nutrition in Clinical Practice Volume 25 Number 1 February 2010 13-15 © 2010 American Society for Parenteral and Enteral Nutrition 10.1177/0884533609356090 http://ncp.sagepub.com hosted at http://online.sagepub.com
Annalynn Skipper, PhD, RD, FADA Financial disclosure: none declared.
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n October 2008, the Centers for Medicare and Medicaid Services (CMS) discontinued the increased rate of reimbursement for certain hospital-acquired conditions if those conditions are considered preventable.1 The fact that one of these conditions is pressure ulcers validates the closely held belief of clinicians in the pressure ulcer community who insist that these ulcers can be prevented and therefore should not occur in healthcare institutions. Because the topics of nutrition and pressure ulcers are inextricably linked in the minds of many people the changes at CMS have refocused attention on the role of nutrition in both prevention and treatment of pressure ulcers. However, pressure ulcers are just one type of wound in a larger category that includes diabetic ulcers, arterial ulcers, venous ulcers, thermal and other traumatic injuries, and surgical incisions. Pressure ulcer guidelines suggest that adequate nutrient intake plays a role in pressure ulcer prevention; however, nutrient recommendations are not included in guidelines for other types of wounds.2-4 Following injury, adequate nutrient intake is recognized as necessary to provide substrate for efficient wound healing or treatment.5 In this issue of Nutrition in Clinical Practice, authors explore nutrition issues in wound healing and pressure ulcer management.6,7 Acute care clinicians are familiar with nutrition treatment for wounds, but the concept of prevention is a new one for many. Shifting attention to prevention has created confusion in acute care practice where subtle changes in nutrient intake to prevent pressure ulcers contrast sharply with the established tradition of making major changes in nutrient intake when wounds fail to heal. As part of institutional attempts to reduce the incidence of pressure ulcers in patients and the associated pain and suffering as well as loss of revenue to the institution, nutrition professionals have been asked to provide nutrition prophylaxis for patients who may only need minor changes in their nutrient intake.
Requests to provide specialized nutrition protocols for pressure ulcer prevention come at a time in nutrition support history when attention is being given to the evidence base of practice. In their review of nutrition and wound healing that appears in this issue, Stechmiller et al6 describe the wound healing cascade and the functions of macronutrients, amino acids, and several vitamins and minerals in wound healing. This article can serve as a basis for a discussion about nutrient intake of patients with various wounds. Also in this issue, Doley et al7 provide a more specific overview of the role of nutrition in pressure ulcer management and incorporate the National Pressure Ulcer Advisory Panel (NPUAP) and European Pressure Ulcer Advisory Panel (EPUAP) guidelines2 that were reissued as this issue of Nutrition in Clinical Practice was going to press. Evidence-based practice depends on guideline authors who prepare recommendations based on the available literature or, where there is no literature, based on expert opinion. The lack of strong evidence and subsequent guidelines supporting specific recommendations for various amino acids, vitamins, and minerals reflects the small body of wound healing literature derived from case reports or small, poorly controlled trials punctuated with 1 or 2 observations of larger groups. Many of the available studies were designed primarily for purposes other than obtaining nutrition data and therefore do not contain detailed descriptions of the population studied, their wounds, or nutrient intake. The literature is also characterized by a tendency to describe oral supplements, enteral nutrition, and parenteral nutrition as single entities rather than complex nutrient mixtures with specialized nutrient profiles. Thus, it is often difficult to evaluate the study participants’ total nutrient intake from all sources. Some studies do not provide basic measures of nutrition status such as weight and height or body mass index. Many older studies use outdated measures for nutrition assessment such as serum levels of albumin and prealbumin, which are likely depressed because of the inflammation associated with the wound rather than because of protein restriction. Another problem, especially with pressure ulcer studies, is that nutrition is not easily separated from confounders such as moisture, activity, sensory perception, and mobility.
From Annalynn Skipper and Associates, Oak Park, Illinois. Address correspondence to Annalynn Skipper, PhD, RD, FADA, Annalynn Skipper and Associates, Oak Park, Il 60303; e-mail:
[email protected].
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14 Nutrition in Clinical Practice / Vol. 25, No. 1, February 2010
Tools and Guidelines A number of organizations publish tools including those used to assess pressure ulcer risk, describe pressure ulcer severity, and measure pressure ulcer healing.8-10 Clinicians are advised to become familiar with these tools and to apply them appropriately. Evidence-based practice guidelines for pressure ulcer prevention and treatment were first published by the Agency for Healthcare Policy and Research in 1992 and 1994.11,12 Most subsequent guidelines are modeled on these recommendations, even though they have been retired. Most guidelines recommend screening patients for pressure ulcer risk, then referral to a registered dietitian or multidisciplinary nutrition support team for evaluation of nutrition status. The revised guidelines from the NPUAP and EPUAP recommend 30-35 kcal/kg and 1.25-1.5 g/kg/d protein, which is probably quite similar to the nutrient intake of the general population.2 They do not recommend supplemental intake of other nutrients unless deficiencies are identified following a formal nutrition assessment and even then do not promote specific amounts of vitamins, minerals, or amino acids. In practice, nutrition guidelines for pressure ulcer prevention and treatment have not universally replaced unsubstantiated recommendations unwittingly promoted by those without higher level training in nutrition and evaluation of the nutrition research literature. This situation suggests that nutrition clinicians have a responsibility to develop an understanding of the difference in practice guidelines, research reports, and traditional practice, and then to collaborate with their colleagues to develop evidence-based protocols for pressure ulcer prevention and wound healing.
What Else Do We Need To Do? Acute care clinicians must still make patient care decisions, because diverse and conflicting guidelines cannot be applied to the same patients. New international guidelines appear to recommend lower energy levels than in the past, but the recommended energy intake of 30-35 kcal/kg for pressure ulcer prevention is higher than many clinicians use in intensive care and general acute care practice. These levels are also higher than calorie levels recommended by proponents of permissive underfeeding, and they contradict the longstanding A.S.P.E.N. recommendation that well-nourished patients will not experience adverse complications if they receive no nutrition for 7-10 days.13,14 Following the belief that “if a little is good, then a lot is better,” clinicians may encounter or use wound healing protocols that recommend or provide nutrients in amounts above the upper limits of nutrient intake recommended in the dietary reference intakes (DRI).15 Many clinicians
ignore the DRI based on the assumption that the sick patients they see in practice have different needs than the healthy individuals for whom the DRI was designed. Still, thought-provoking discussion may result after reviewing the upper limits for vitamins and minerals and considering whether sick patients can increase their ability to metabolize nutrients in excess of needs. Another item for consideration is the value of documenting total nutrient intake. Again using the concept that if a little is good, a lot is better, clinicians often prescribe nutritional supplements because it is easier than obtaining and evaluating a history of food and nutrient intake. However, the possibility of excess nutrient intake is real, and analysis of total nutrient intake helps to avoid the additional costs of oversupplementation. Thus, clinical judgment is required along with frequent and diligent follow-up to ensure that nutrition prescriptions are modified appropriately as the patient’s condition changes so that over- or underfeeding does not persist and deter wound healing.
What Else Do We Need to Know? Most wounds heal uneventfully within a few weeks of injury. There is justifiable concern when they do not. However, it is unclear whether consistent definitions of normal and abnormal wound healing, wound healing failure, and chronic wounds are widely agreed upon and commonly used in clinical practice. Standard terminology could help clinicians identify and describe patients whose wounds would qualify them as candidates for nutrition intervention. An important line of research is to further define nutrient needs for wound healing. The tradition of “hyperalimentation” has not been supported in practice but is still encountered in some segments of the wound healing community, perhaps disguised as “nutrition pharmacology.” Still, there are indications that nutrient needs for wound healing are not as large as formerly thought. At least 2 small studies suggest that energy needs for patients with pressure ulcers may not be higher than for patients without pressure ulcers.16,17 Larger studies are needed to confirm requirements for energy and develop recommendations for other nutrients. Clinical trials evaluating wound healing and nutrition are difficult to conduct because sufficient numbers of participants who meet inclusion and exclusion criteria are not usually found within a single practice or institution. Multicenter trials are needed that follow patients over sufficient periods of time to evaluate the impact of alterations in nutrient intake. Interdisciplinary collaboration is needed between those with expertise in wound healing and those trained in nutrition and nutrition research so that research results are usable by clinicians in both groups. Wound management has always been an important part of acute care, but with shortened hospital stays, the
Pressure Ulcers and Wound Healing / Skipper 15
interval required for wounds to heal is greater than the duration of the hospital stay. Thus, most patients with wounds are discharged before healing is complete. The typical follow-up for patients discharged with wounds is not well described, but unless patients are transferred to another healthcare facility, close follow-up by someone with nutrition training is unlikely. Without appropriate monitoring by trained nutrition clinicians, patients may become victims of untreated declining food and nutrient intake or nutrition misinformation, both of which can deter wound healing and increase costs to patients and, if they have them, their insurers. Practice-based research into the nutrition services that would improve the care of noninstitutionalized patients with wounds is needed.
What Should We Discontinue? In theory, the nutrition prescription for a patient with a wound should be based on what is necessary to support normal function plus the needs for tissue regeneration and repair, as well as replacement of nutrients lost in wound exudate. As wound management has become more diverse and sophisticated, the effect of different systems on both the volume of exudate and its nutrient composition is unknown. Thus, there is potential for wounds to have a highly variable impact on nutrient losses and potentially nutrient needs. Pressure ulcer staging criteria have been recently revised to improve clarity and clinical utility.9 These stages are sometimes used as the basis for recommending modifications in nutrient intake. However, this approach is at best flawed because pressure ulcer stages are based solely on wound depth. Using pressure ulcer stages to individualize the nutrient prescription places the clinician in the untenable position of providing the same amount of additional nutrients to a patient with a thumbnail-sized lesion as is provided to another patient with 3 pressure ulcers connected by tunnels that cover an area equivalent to a standard sheet of writing paper. Nutrient losses from wound exudates could easily be measured and intake adjusted based on wound size and exudate volume. However, this is probably rare in clinical practice because it is difficult to collect sufficient volumes of wound exudate for laboratory analysis.
Conclusion We are in the infancy of learning about nutrient needs for wound healing. The articles in this issue of Nutrition in Clinical Practice provide some insight into the problems and issues clinicians face when confronted with wounds. We need more clinicians to research the needs of these
complicated patients and to share their findings with us. In the interim, existing clinical guidelines based on expert opinion are probably our best bet for individualizing the nutrition prescription for all patients under our care.
References 1. Medicare program: changes to the hospital inpatient prospective payment systems and fiscal year 2008 rates; final rule. Fed Regist. 2007;72:47129-48175. To be codified at 42 CFR Vol Parts 411, 412, 413, and 489. 2. European Pressure Ulcer Advisory Panel and National Pressure Ulcer Advisory Panel. Prevention of Pressure Ulcers: Quick Reference Guide. Washington, DC: National Pressure Ulcer Advisory Panel; 2009. 3. Hopf HW, Ueno C, Aslam R, et al. Guidelines for the prevention of lower extremity arterial ulcers. Wound Repair Regen. 2008;16: 175-188. 4. Robson MC, Cooper DM, Aslam R, et al. Guidelines for the prevention of venous ulcers. Wound Repair Regen. 2008;16:147-150. 5. European Pressure Ulcer Advisory Panel and National Pressure Ulcer Advisory Panel. Treatment of pressure ulcers: quick reference guide. Washington, DC: National Pressure Ulcer Advisory Panel; 2009. 6. Stechmiller, et al. Understanding the role of nutrition and wound healing. Nutr Clin Pract. 2010;25(1):61-68. 7. Doley. Nutritional management of pressure ulcers. Nutr Clin Pract. 2010;25(1):50-60. 8. Bergstrom N, Braden B. A prospective study of pressure sore risk among institutionalized elderly. J Am Geriatr Soc. 1992;40:747-758. 9. Black J, Baharestani M, Cuddigan J, et al. National Pressure Ulcer Advisory Panel’s updated pressure ulcer staging system. Adv Skin Wound Care. 2007;20:269-274. 10. Pressure Ulcer Scale for Healing (PUSH). PUSH tool version 3.0. National Pressure Ulcer Advisory Panel. http://www.npuap.org/ PDF/push3.pdf. Accessed October 23, 2009. 11. Agency for Healthcare Research and Quality. Pressure ulcers in adults: prediction and prevention. Clinical Practice Guideline No. 3. May 1992. http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi? book=hsahcpr&part=A4409. Accessed November 3, 2009. 12. Department of Health and Human Services; Agency for Healthcare Research and Quality. Optimizing prevention and Healthcare Management for the Complex Patient (R21). http:// grants.nih.gov/grants/guide/rfa-files/RFA-HS-08-003.html. Accessed January 15, 2009. 13. Malone AM. Permissive underfeeding: its appropriateness in patients with obesity, patients on parenteral nutrition, and nonobese patients receiving enteral nutrition. Curr Gastroenterol Rep. 2007;9:317-322. 14. A.S.P.E.N. Board of Directors and the Clinical Guidelines Task Force. Guidelines for the use of parenteral and enteral nutrition in adult and pediatric patients. JPEN J Parenter Enteral Nutr. 2002;26(1 suppl):1SA-138SA. 15. Dietary Reference Intakes: Recommended Intakes for Individuals. Washington, DC: National Academy of Sciences, Institute of Medicine, Food and Nutrition Board; 2005. 16. Dambach B, Sallé A, Marteau C, et al. Energy requirements are not greater in elderly patients suffering from pressure ulcers. J Am Geriatr Soc. 2005;53:478-482. 17. Aquilani R, Boschi F, Contardi A, et al. Energy expenditure and nutritional adequacy of rehabilitation paraplegics with symptomatic bacteriuria and pressure sores. Spinal Cord. 2001;39:437-441.
