Diagnostic tests can be an important part of wound assessment, providing valuable information about the patient’s health status as well as the patient’s potential for healing. Although you as a practitioner may not order all of these tests, tests are often available as part of the patient file or may be requested from the patient’s primary caregiver. No matter how you get this information, it’s important to know how to apply it to the case at hand.
Patients with chronic health conditions will often have blood work done to monitor their health. You can use this information to guide your care. It’s important to know how to interpret these results.
- Red blood cell count, hemoglobin and hematocrit– these tests are related and are often performed together. When they are abnormally low they point to anemia. Anemia affects the body’s ability to carry oxygen-rich hemoglobin to the cells and tissues that need it. Wound healing can be impaired in patients who have anemia.
- White blood cell count– a high white blood cell count may signal infection, while a low white blood cell count may signal autoimmune disease, overwhelming infection or abnormal immune function. Whether low or high, an abnormal white blood cell count signals a problem with the body’s ability to fight off infection.
- Platelet count– the function of platelets is to stop bleeding. Platelets work with other clotting factors to achieve hemostasis. When platelets are low, wounds may bleed more and debridement and other procedures may lead to excessive bleeding.
- Serum albumin– albumin prevents fluid from leaking out of the blood vessels. When albumin is low, patients may experience edema and weeping of the tissues. Albumin can also be used to determine whether a person’s diet has sufficient amounts of protein, as albumin is one of the major groups of protein. Malnutrition can lead to poor wound healing, thus low albumin levels can indicate poor wound healing.
- Blood glucose/Hgb A1C– many patients with diabetes develop chronic wounds that take a long time to heal. It is important that these patients do all they can to control blood glucose levels. Blood glucose is a snapshot of a patient’s blood glucose at a given time- Hgb A1C is used to determine how well a patient has controlled their blood glucose over the past 90 days.
- Wound culture– wound cultures can be used to determine whether a wound is infected with bacteria and, if it is, what type of bacteria is present. It is also used to determine what antibiotic the bacteria are susceptible to (i.e. what antibiotic will successfully treat the wound infection).
These are just a few of the blood tests available that can shed light on a patient’s clinical condition and help you determine whether any issues with healing are likely to occur. Blood tests can also be used to determine response to treatment (i.e. an elevated white blood cell count should decrease after antibiotic therapy).
X-rays– x-rays can be used to identify whether a foreign object is present in the wound or surrounding tissue, whether a fracture is present or whether there is infection in the bone (osteomyelitis). An x-ray may be ordered when a wound is associated with a traumatic injury or when there is suspicion that the bone is infected.
Arteriogram/Venogram– these tests are used to view the inside of arteries or veins. A dye is injected into an artery or vein and x-rays are taken to see how the dye flows through the blood vessels. This test may be used to assess blocked or damaged veins or arteries or to assess the severity of venous or arterial disease.
There are many other tests that are used to assess health. This list is not exhaustive- it is meant to get you thinking about how you can use diagnostic tests as an adjunct to assessment and planning when caring for a patient with a wound, particularly a patient with a wound that is chronic or has stalled in the healing process.
If you enjoy learning about wound healing and the factors affecting wound healing, perhaps you should consider wound certification. Wound Educators provides online certification education and prepares you to become a certified wound care practitioner.
Meyers, B (2008). Wound Management: Principles and Practice. 2nd edition. Pearson Prentice Hall. Upper Saddle River, New Jersey. pg. 45
Hess, T (2011). Checklist for factors affecting wound healing. Advances in Skin and Wound Care, 24(4); p 192.