Nutritional deficits affect patients who are at risk for pressure injury/ulcer formation by both increasing the risk and impeding wound healing.  A retrospective study by Fry et al. found that patients in the acute care setting with malnutrition were four times more likely to develop pressure ulcers.[1] 

A three-pronged etiology-based definition of malnutrition was proposed by the Academy of Nutrition and Dietetics and the American Society for Parenteral and Enteral Nutrition which relates the condition to the patient setting.

• Malnutrition in the context of social or environmental circumstances (starvation-related malnutrition).  May be due to financial or social reasons, or caused by anorexia nervosa.
• Malnutrition in the context of acute illness or injury, such as organ failure, cancer, rheumatic arthritis, or sarcopenic obesity.
• Malnutrition in the context of chronic illness, such as major infections, burns, trauma, or closed head injury.[2]

They further listed six characteristics of malnutrition:

• Insufficient energy intake
• Weight loss
• Loss of muscle mass
• Loss of subcutaneous fat
• Localized or generalized fluid accumulation that may sometimes mask weight loss
• Diminished functional status as measured by hand-grip strength.²

The relationship between loss of body mass (over a 4-week period) and wound formation and/or healing is as follows:

• 10 % loss – impaired immune response, increased risk of infection
• 20% loss – impaired or delayed wound healing, increased risk of infection, thin skin
• 30% loss – no wound healing, increased incidence of pressure ulcers
• 40% loss – death, usually from pneumonia[3]

Early identification and treatment of vulnerable patients is an important component of prevention.  In addition to the risk assessment tools discussed last week, there are more specific, validated assessment tools for malnutrition.  The Canadian Nutrition Screening Tool asks the patient about weight loss within the past 6 months and eating habits over the last week.[4]  The MEAL scale, developed for use in the out-patient wound care setting, includes number of wounds, meals eaten in a typical day, appetite loss, and level of activity.  The total score is used to screen patients at risk for delayed healing.[5]  Other screening tools are discussed in the NPUAP/EPUAP/PPPIA guidelines.[6]

Caloric intake for patients at risk for or with a PU is recommended as 30-35 kcal/kg body weight for adults; protein intake, 1.25 to 1.5 grams of protein/kg body weight.⁶   Specific individualized needs are best determined by a registered dietician or nutrition specialist, and a referral to the specialist is recommended for any patient suspect of being malnourished.  The patient’s ability to self-feed is also an important aspect of patient screening for malnutrition, especially for anyone on large doses of pain medications (e.g. a patient being treated for calciphylaxis) or who are cognitively impaired and cannot achieve sufficient oral intake.  In these cases, short-term use of enteral or parenteral feeding may be indicated in order to optimize healing potential.

It should be noted that serum albumin and pre-albumin are generally not considered reliable indicators of nutritional status.  Changes in acute phase proteins do not consistently or predictably change with weight loss, calorie restriction or nitrogen balance; changes appear to reflect severity of inflammatory response rather than nutritional status. Inflammation can, however, increase the risk of malnutrition by increasing metabolism. Thus the relevance of laboratory values as indicators of malnutrition is limited.⁶

The risk of malnutrition and its effect on formation and healing potential of PUs emphasizes the importance of a multi-disciplinary approach to caring for this patient population in all settings, including home, acute and long-term care.

[1] Fry DE, Pine M, Jones BL, Meimban RJ.  Patient characteristics and the occurrence of never events.  Archives of Surgery.  2010;145(2):148-151.

[2] Collins N, Friedrich L.  Appropriately diagnosing malnutrition to improve wound healing.  Wound Clinic.  2016;10(11):10-12.

[3] Demling RH. Nutrition, anabolism, and the wound healing process: an overview.  ePlasty. 2009;9:65-94.

[4] Laporte M.  The Canadian Nutrition Screening Tool. Advances in Skin and Wound Care. 2017;30(2):64-65.

[5] Fulton J, Evans B, Miller S, et al. Development of a nutrition screening tool for an outpatient wound center.  Advances in Skin and Wound Care. 2016;29(3):136-142.

[6] National Pressure Ulcer Advisory Panel, European Pressure Ulcer Advisory Panel and Pan Pacific Pressure Injury Alliance. Prevention and Treatment of Pressure Ulcers: Nutrition – an extract from the Clinical Practice Guideline. Emily Haesler (Ed.). Cambridge Media: Osborne Park, Western Australia; 2014.  Available at www.internationalguideline.com/static/pdfs/01-NPUAP-EPUAP-PPPIA%20Nutrition%20Extract%20of%20the%20CPG%202017.pdf. Accessed 9/22/2019.

Further information on the effect of protein energy malnutrition, as well as other factors that can impede wound healing, can be found at the following:

Hamm RL, Luttrell T.  Factors that impede wound healing.  In Hamm R (Ed), Text and Atlas of Wound Diagnosis and Treatment: 2^nd edition.  New York: McGraw Hill Education.  2019, 321-346.  Available at https://accessphysiotherapy.mhmedical.com/book.aspx?bookid=1334.