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What Clinicians Should Know About Comorbidities and Complex Wounds

Practice Accelerator
February 28, 2023


The presence of more than one chronic condition in an individual is often referred to as comorbidity. Various comorbidities can interfere with, or inhibit, wound healing processes. These conditions are associated with complex management, economic burden, and poor outcomes.1 Some of these obstacles to healing include nutritional abnormalities, aging, diabetes, and infection to name a few.2 The prevalence of such comorbidities in patients with complex wounds reinforces the importance of identifying these conditions and finding ways to mitigate the risks they pose to wound healing.

Inadequate Nutrition

What It Does

Because wound healing requires protein and energy, those with protein-energy malnutrition (PEM) and other nutrient deficits are at a higher risk of wound chronicity. Deficits in carbohydrates and certain vitamins and minerals can also factor in stalled wound healing.2,3 Malnourished patients may have decreased immune function, sarcopenia, reduced collagen synthesis, diminished tensile strength, loss of function, as well as higher risk of infection, hospital-acquired conditions, and mortality. Patients over the age of 65 and those within the residential and inpatient settings are at a greater risk for PEM.3

How to Identify It

With the help of dietary experts on the multidisciplinary team, clinicians can identify potential malnutrition by observing 6 key characteristics.4 Theses characteristics were developed by Academy of Nutrition and Dietetics (ASPEN) in 2012 who recommend patients demonstrating 2 or more of the following conditions may be diagnosed with malnutrition5:

  • Weight loss
  • Inadequate energy intake
  • Loss of muscle mass
  • Loss of subcutaneous fat
  • Fluid accumulation (may obscure extent of patient’s weight loss)
  • Reduced hand grip strength (identifies functional status)4,5

A more in-depth nutrition assessment by a dietician may follow to help establish a comprehensive plan of care.4

How to Help

The interdisciplinary team can improve patient nutrition through oral supplements, protein fortified or nutrient-dense foods, education, and, if necessary, enteral or parenteral nutrition.3-5 Although the recommended daily intake (RDA) for protein is the same for both young and aging adults, research suggests that those of the aging population should consume more dietary protein, accounting for several factors including changes in protein metabolism, and to support the management of acute and chronic conditions. Specifically, literature suggests that those age 65 and older with injuries should consume 1.2-1.5 grams of protein per kilogram of body weight while malnourished patients of this population need approximately 2.0 grams of protein per kilogram of body weight.3-5 It is estimated that 35% of those in residential care do not meet RDA for dietary protein intake.3 Decreases in appetite, cognitive impairment, physiological issues chewing and swallowing, sociocultural factors, and financial and access issues are potential obstacles to reaching a patient’s dietary goals.3 Despite the various reasons why a patient may not adhere to a nutrition plan, through fostering a strong patient-provider partnership, clinicians may work towards overcoming these barriers. For instance, patients who cannot afford or cannot access a diet conducive to wound healing may benefit from referral to community social service or food support agencies.


What It Does

Approximately 500 million people have diabetes mellitus (DM) and 25% of patients with DM who develop a wound will suffer from wound chronicity.6 Diabetes has several associated complications that pose unique challenges to wound development and healing, and patients may not be aware of the details of these risks. Hyperglycemia can lead to blood vessel narrowing and decrease the ability of red blood cells to transport nutrients to the tissues.6,7 In addition, diabetic neuropathy may cause a loss of sensation in the extremities that increases the risk of unrecognized injury, especially foot ulceration. Diabetes also causes immune cell dysfunction that can lead to infection. All these biochemical, vascular, and neuropathic factors can contribute to nonhealing or delayed healing of wounds.7

How to Identify It

Although a wound care clinician may not be the one to diagnose diabetes, having an awareness of its presenting symptoms may be helpful in discussions with the care team to make sure a patient receives the care they need. Signs of diabetes include the following8,9:

  • Excessive hunger, thirst, and urination
  • Fatigue
  • Numbness or tingling of the hands and feet
  • Blurry vision
  • Slow-healing wounds
  • More infections than is usual for the patient

Some patients may be asymptomatic and it is possible that a patient presenting with a complex wound could be unaware that they have the disease. The diagnosis of diabetes is established primarily by blood glucose testing, usually by a primary care provider or endocrinologist.8,9

How to Help

Wound care clinicians can assist patients with diabetes by encouraging them to incorporate best practices and engage with care team members such as primary care, endocrinologists, podiatrists, dietitians, diabetes educators, optometrists or ophthalmologists, and others as indicated. Since clinical encounters for complex wounds, like diabetic foot ulcers, are often at regular intervals, wound care clinicians may be uniquely suited to provide related education and referrals that could benefit the healing trajectory and overall health of the patient.


What It Does

The skin of older adults is fragile and more prone to breakdown. In addition, the aging population experiences the following risk factors that can impact wound healing8,10:

  • Higher infection risk
  • Diminished inflammatory response
  • Lower antibody production
  • Endocrine slowdown

This age group also often has cardiovascular and pulmonary diseases that impair oxygen delivery to tissues, and thereby delay wound healing.1

How to Help

Clinicians should identify any other comorbidities and ensure that these conditions are managed as effectively as possible.11 Frequent skin checks are necessary as the skin becomes older, and a clinician should check for details like skin tearing and skin trauma from adhesives or certain clothings.10 Dressing selection must take into account the potential for skin fragility.10


What It Does

Bacteria can proliferate in the wound and on the skin. If present at levels causing infection, these organisms may use oxygen and nutrients needed for wound healing and may have byproducts that pose further challenges.1 If not appropriately treated, a wound infection can spread and lead to tissue necrosis, deeper infection, need for surgical drainage or debridement, or even sepsis or amputation.

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How to Identify It

To evaluate for wound infection, clinicians use culture techniques, imaging, and bloodwork values, although these can be inconclusive, especially in some patients with immunocompromise or diabetes. In these patients, secondary signs of infection are important, such as serous exudate with concurrent inflammation, delayed healing or wound breakdown, wound base pocketing, and malodor.11,12 The concept of biofilm and early, frequent intervention thereof, is also vital in one’s understanding of mitigating infection and the complexities it poses in wound care. In some patients with immunocompromise or diabetes, however, these tests are not diagnostic. In these patients, secondary signs of infection are used, such as serous exudate with concurrent inflammation, delayed healing or wound breakdown, wound base pocketing, and malodor.11,12

How to Help

Topical, oral, or intravenous antibiotic therapy may be applied for wound infections as indicated, and infectious disease specialists may be asked to consult. Accurate culture results can help guide proper antibiotic selection, as does the depth and extent of the infection. Surgical intervention to drain or remove infected, devitalized tissue may also occur.12


By understanding the effects of specific comorbidities on wound healing and identifying these comorbid conditions accurately, clinicians are well on their way to helping their patients achieve optimal wound healing outcomes, especially for complex wounds.


  1. Valdera JM, Starfield B, Sibbald B, et al. Defining Comorbidity: Implications for Understanding Health and Health Services. Ann Fam Med. 2009;7(4):357-363. doi: 10.1370/afm.983
  2. Chandan K. Human Wound and its Burden: Updated 2020 Compendium of Estimates. Adv Wound Care. 2020;10(5)281-292.
  3. Mathewson SL, Azevedo PS, Gordon AL, et al. Overcoming protein-energy malnutrition in older adults in the residential care setting: A narrative review of causes and interventions. Aging Research Reviews. 2021;70. doi:
  4. Tyler RD, Guenter P. Identifying malnutrition: from acute care to discharge and beyond. Nurse Pract. 2017;42(4):18-24. doi:10.1097/01.NPR.0000513334.61944.8e
  5. White JV, Guenter P, Jensen G, et al. Consensus Statement: Academy of Nutrition and Dietetics and American Society for Parenteral and Enteral Nutrition. JPEN. 2021;36(3): 275-283.
  6. Burgess JL, Wyant WA, Abujamra BA, et al. Diabetic Wound-Healing Science. Medicina. 2021;57(10):1072.
  7. Spampinato SF, Caruso GI, De Pasquale R, Sortino MA, Merlo S. The Treatment of Impaired Wound Healing in Diabetes: Looking among Old Drugs. Pharmaceuticals (Basel). 2020;13(4):60. doi:10.3390/ph13040060
  8. Molnar JA, Underdown MJ, Clark WA. Nutrition and Chronic Wounds. Adv Wound Care. 2014;3(11):663-681. doi:10.1089/wound.2014.0530
  9. Centers for Disease Control and Prevention. Diabetes symptoms. 2022. Accessed January 31, 2023.
  10. LeBlanc K, Campbell K. Best practice recommendations for the prevention and management of skin tears in aged skin. Wounds International. 2018. www.
  11. Patient populations: barriers to care. WoundSource. Published March 31, 2022. Accessed January 31, 2023.
  12. Malone M, Schultz G. Challenges in the diagnosis and management of wound infection. Br J Dermatol. 2022;187(2):159-166. doi:10.1111/bjd.21612

The views and opinions expressed in this blog are solely those of the author, and do not represent the views of WoundSource, HMP Global, its affiliates, or subsidiary companies.