The nurse is calculating the absolute neutrophil count (ANC) of a child with lymphoma. The CBC with differential lists bands 3%, Segs 10%, and WBC’s 2000.
What is the ANC?
The correct answer and explanation is :
To calculate the Absolute Neutrophil Count (ANC), the formula is as follows:
[
\text{ANC} = \text{WBC} \times (\text{Segs percentage} + \text{Bands percentage})
]
Where:
- WBC is the total white blood cell count
- Segs refer to segmented neutrophils (mature neutrophils)
- Bands refer to band cells (immature neutrophils)
In this case:
- WBC = 2000
- Segs = 10%
- Bands = 3%
Step 1: Convert the percentages to decimal form.
- Segs = 10% = 0.10
- Bands = 3% = 0.03
Step 2: Add the Segs and Bands percentages.
[
\text{Segs} + \text{Bands} = 0.10 + 0.03 = 0.13
]
Step 3: Multiply the total WBC by the sum of the Segs and Bands.
[
\text{ANC} = 2000 \times 0.13 = 260
]
So, the ANC is 260 cells/µL.
Explanation:
The ANC is a measure of the number of neutrophils in the blood, which are essential in the body’s defense against infection. Neutrophils include both segmented neutrophils (Segs) and band neutrophils (Bands), which are immature forms of neutrophils. In a complete blood count (CBC) with differential, these neutrophil counts are provided as percentages, and the ANC calculation is done to determine how many neutrophils are available to fight infections.
The ANC is important for monitoring the risk of infection, especially in patients undergoing treatment for conditions like lymphoma, where chemotherapy may lead to neutropenia (low neutrophil count). A low ANC can indicate a higher risk for infections, requiring interventions such as antibiotics or isolation to prevent exposure to pathogens. A normal ANC is generally considered to be above 1500 cells/µL, while an ANC less than 1000 cells/µL may be concerning for increased infection risk. An ANC less than 500 cells/µL is considered severe neutropenia, which is a medical emergency. In this case, with an ANC of 260, the child is at significant risk for infection.