- Infection / Increased bacterial load – When bacteria are present within a wound, the body produces many of its own natural responses to fight off the unwanted bacteria. These responses along with tissue breakdown due to the bacteria prevent wounds from healing. An open wound is also a break in the body’s natural protective armor (the skin) which allows bacteria to enter our bodies and sometimes move into systemic circulation causing more severe infections like sepsis.
- Maceration – when a wound remains too moist, it cannot heal. Drainage from the wound itself can also cause further skin breakdown on the healthy tissue surrounding the wound if not treated properly
- Necrosis – dead tissue which usually appears as yellow moist tissue or even leathery yellow or black tissue must be removed for a wound to heal properly.
- Pressure – When pressure is present at a wound site, the blood supply to the tissue in that area is disrupted and blood flow is decreased to an already injured area. This is most commonly seen in persons with decreased mobility as well as diabetic feet but can happen almost anywhere on the body.
- Trauma and Edema – Blood supply to wounds are also decreased when edema is present. This edema can also cause oozing of drainage at wound sites causing further problems.
- Systemic Causes – Many times overlooked, wound healing can be delayed due to systemic factors (within the entire body not just at the wound site). These can include the following:
- Age – As we age, our bodies are unable to maintain health as compared to younger patients. Older patient’s more commonly have comorbidities including decreased nutritional intake, altered hormonal responses, weaker immune systems, circulatory issues, poor hydration, all which delay healing wounds and increase risk for skin breakdown.
- Body Type – Body types also affect wound healing. Obese patients tend to have more adipose tissue. Adipose tissue has less blood supply compared to other types of tissues. Some obese patients also have protein malnutrition which also prevents wounds from healing. Likewise, underweight patients are at increased risk for pressure trauma, and emaciated patients tend to have poor oxygen supply and poor nutritional stores which interfere with wound healing.
- Chronic diseases – Most of us as we age deal with some chronic disease. Whether it is hypertension, coronary artery disease, peripheral vascular disease, cancer, or diabetes mellitus, each disease delays some part of the wound healing process. This is also why close interaction and communication with your primary care physician is so important to be continued during your wound healing process.
- Immunosuppression or radiation therapy – Suppression of the immune system can be present for a multitude of factors. Loss of spleen, genetic inheritance or development of Immunoglobulin deficiency, diseases like HIV, or medications including steroids, methotrexate, and other drugs used to treat autoimmune diseases can cause immunosuppression. Stress, inappropriate sleep, or over exhaustion can also cause immunosuppression. Radiation therapy causes changes in the skin which can lead to ulceration both during and after radiation treatment.
- Laboratory Values – Not only are nutritional markers important, hemoglobin levels should be evaluated to rule out anemia (decreases the oxygen carrying capacity of the body which delays wound healing), blood sugar levels, thyroid function, and even hepatic and renal function should be assessed for any possible
- Nutritional Status – Visual appearance of the patient is not a reliable indicator of nutritional status. Patients should be evaluated to see if they are receiving proper amounts of many nutrients, vitamins, and minerals. Protein is essential for cell growth, amino acids and fatty acids are also important. Iron, B12, and folate are essential for red blood cell production
- Vascular insufficiency – Wounds located on the lower extremities are commonly complicated by alterations in blood flow both venous and arterial. Many wounds can have multiple causes. For example, many diabetics also have arterial insufficiency components as well which delay wound healing and can prevent wound healing if not addressed. Many therapies for lower extremities also should have vascular evaluation done before being started including compression therapy. The clinician must identify the type of ulcer to ensure appropriate topical and supportive therapies.