The differential WBC count indicates the percentage of each type of leukocyte present per cubic millimeter of whole blood. If necessary for further evaluation of results, the percentage for each cell type can be multiplied by the total WBC count to obtain the absolute number of each cell type present.
Causes of alterations in the differential WBC count according to type of leukocyte are presented in Table 1-11. An increase in immature neutrophils (i.e., bands, stabs) indicates the body's attempt to produce more neutrophils in response to the pathological process. A decreased neutrophil count is fairly common in children during viral infections. An increase in bands is sometimes referred to as a "shift to the left." This terminology derives from the following traditional headings used on laboratory slips to report WBC differential results: Bands, Neutrophils, Eosinophils, Basophils, Monocytes, and Lymphocytes.
In contrast, the meaning of a "shift to the right" is less well defined. This may refer to an increase in neutrophils or other granulocytes or to an increase in lymphocytes or monocytes.
| Conventional Units | SI Units | |
|---|---|---|
| Bands | 3-8% | 0.03-0.08 |
| Neutrophils | 54-75% | 0.54-0.75 |
| Eosinophils | 1-4% | 0.01-0.04 |
| Basophils | 0-1% | 0-0.01 |
| Monocytes | 2-8% | 0.02-0.08 |
| Lymphocytes | 25-40% | 0.25-0.40 |
Nursing Care Before the Procedure
Client preparation is the same as that for any study involving the collection of a peripheral blood sample (see Appendix I).
A venipuncture is performed and the sample collected in a lavender-topped tube. A capillary sample may be obtained in infants and children as well as in adults for whom venipuncture may not be feasible.
Nursing Care After the Procedure
Care and assessment after the procedure are the same as for any study involving the collection of a peripheral blood sample (see Appendix I).