Question

A newborn infant has a WBC count of 37,000/μl with the differential count revealing the presence of 50 nRBCs per 100 WBCs. What is the corrected WBC count?

a) 15,000/μl
b) 24,700/μl
c) 27,300/μl
d) 12,500/μl

Answer 1

To calculate the corrected WBC count, divide the number of nRBCs by the total number of WBCs and multiply by 100. Subtract this percentage from 100% to obtain the percentage of normal WBCs. Finally, multiply the percentage of normal WBCs by the total WBC count to get the corrected WBC count.

Step-by-step explanation:

To calculate the corrected WBC count, we need to account for the presence of nucleated red blood cells (nRBCs). First, we determine the percentage of nRBCs in the differential count by dividing the number of nRBCs (50) by the total number of WBCs (37,000) and multiplying by 100. So, the percentage of nRBCs is 0.135 (13.5%). Next, we subtract this percentage from 100% to get the percentage of normal WBCs (86.5%). Finally, we calculate the corrected WBC count by multiplying the percentage of normal WBCs (86.5%) by the total WBC count (37,000).

Corrected WBC count = 0.865 x 37,000 = 31,985/μl

Therefore, the corrected WBC count is approximately 31,985/μl.