A CBC, or complete blood count is a common lab test that occupational therapists may encounter as lab values in the electronic medical record, or EMR. CBC – as the name implies, includes both red and white blood samples. White blood cells are called leukocytes. Leuko- means white.
Leukemia is cancer affecting white blood cells. In leukemia, the WBCs don’t function like normal WBCs and as cancer often involves too much cell division, the “white” blood cells divide too quickly and eventually crowd out normal cells, including the red ones. So represented graphically, there are less red blood cells in a non-leukemia patient compared to a leukemia patient, who likely has less. Or if you are into Star Wars, leuko sounds like Luke Skywalker, who often wore white outfits.
White blood cells are further divided into neutrophils, eosinophils, basophils, lymphocytes, and monocytes.
Never Let Monkeys Eat Bananas – can help you remember neutrophils, lymphocytes, monocytes, eosinophils, and basophils. This mnemonic is also the order from average higher percentage to lowest; so about 60% of white blood cells are neutrophils, but only 1% are basophils.
Let’s talk about clinical implications. An increased white blood count is known as leukocytosis. Low white blood count is called leukopenia and neutropenia. In general, an increased white blood count can be a sign of infection. Leukocytosis can also be due to inflammation, malignancy, trauma, dehydration, tissue injury, malignancy, even stress. Patients with increased WBC may present with fever, lethargy, dizziness, bruising, and painful joints. Causes of low white blood count include anemia, HIV, autoimmune disorders, and diabetes. Patients with low white blood count may present with weakness, fatigue, headache, and dyspnea.
In terms of timing, white blood count is often lowest in the morning. So if you work with a patient with a trending high blood count, you may want to see them in the morning, for example. If you work on the oncology unit, you will often see patients with leuko or neutro-penia. With these patients, you should follow standard precautions and perform good hand hygiene. Some signs will be up at the door requiring you to don a mask and gloves even just to walk into the room because of the risk of infection. Patients who have infections will likely have decreased performance, so grade your activities accordingly and check their vitals such as oxygen demand.
Depending on how low the white blood count is, patients with leukopenia may need to have therapy held. In extremely low white blood count patients, such as less than 500, therapy can be extremely dangerous and even fatal, so be sure to check this lab value. Always use a symptoms-based approach when determining how appropriate OT will be and the activity you will participate in as it’s a balance between safety and immobility or deconditioning.