Master WBC Differential Lab Value with Picmonic for Nursing RN

An increased WBC count (greater than 11,000) is often indicative of infection, while a decreased WBC count (less than 4,500) indicates the patient is becoming immunosuppressed. Remember that steroids will elevate the WBC count even though the patient does not have an infection.

Neutrophils are the primary-acting leukocytes in the body. A neutrophil is a phagocytic cell that responds to an inflammatory response. Segmented neutrophils are mature neutrophils. They are the most effective at phagocytosis. An increase in segmented neutrophils indicates that the body has and is responding to an infection or tissue injury.

Bands are immature neutrophils. If there is an increase of band neutrophils in the system, it is called a “shift to the left,” which is seen in patients with an acute infection.

Lymphocytes are primarily activated during an immune response (cellular and humoral). There are three different types of lymphocytes: Natural Killer (NK) cells, B cells, and T cells. They are increased in chronic bacterial and viral infections but decreased in sepsis.

Monocytes are found in the bloodstream and are effective phagocytic cells. However, when monocytes migrate into the tissue, they are known as macrophages.

Eosinophils have a phagocytic function but are not as effective. These cells assist in engulfing antigen-antibody complexes during an allergic response. The exact mechanism is unknown, but they also help in defending against parasitic infections

Basophils have a similar function to mast cells. When activated, they release histamine and leukotrienes, which help mediate allergic and hypersensitivity responses.