Davis's Lab & Diagnostic Tests

Complete Blood Count, RBC Count

Complete Blood Count, RBC Count is a topic covered in the Davis's Lab & Diagnostic Tests.

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Common Use:
To evaluate the number of circulating red cells in the blood toward diagnosing disease and monitoring therapeutic treatment. Variations in the number of cells is most often seen in anemias, cancer, and hemorrhage.

Whole blood collected in a lavender-top (EDTA) tube.

Normal Findings:
(Method: Automated, computerized, multichannel analyzers)

AgeConventional Units (106 cells/microL)SI Units (1012 cells/L) (Conventional Units × 1)
Cord blood3.61–5.813.61–5.81
0–1 wk4.51–6.014.51–6.01
2–3 wk3.99–6.113.99–6.11
1–2 mo3.71–6.113.71–6.11
3–6 mo3.81–5.613.81–5.61
7 mo–1 yr3.81–5.213.81–5.21
2–6 yr3.91–5.313.91–5.31
7–15 yr3.99–5.213.99–5.21
16–18 yr4.21–5.414.21–5.41
Values are decreased in pregnancy related to the dilutional effects of increased fluid volume and potential nutritional deficiency related to decreased intake, nausea, and/or vomiting. Values are slightly lower in older adults associated with potential nutritional deficiency. Values are slightly lower in older adults.

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