In what unit is hemoglobin concentration recorded when estimated from PCV?

In what unit is hemoglobin concentration recorded when estimated from PCV?

• A. mg/dL
• B. mmol/L
• C. g/dL
• D. g/L

Answer: (C)

Understanding how hematocrit relates to hemoglobin is key. Packed cell volume (PCV) is the hematocrit, the percent of blood volume made up of red cells. A handy rule used in practice is that hemoglobin concentration in g/dL is roughly PCV divided by 3. This keeps the result in the familiar g/dL units used for Hb. For example, a PCV of 45% estimates Hb as about 15 g/dL. The other units listed—mg/dL, mmol/L, or g/L—aren’t the standard units produced by this quick estimate, since the practical conversion from hematocrit to Hb with this rule yields g/dL.

Understanding how hematocrit relates to hemoglobin is key. Packed cell volume (PCV) is the hematocrit, the percent of blood volume made up of red cells. A handy rule used in practice is that hemoglobin concentration in g/dL is roughly PCV divided by 3. This keeps the result in the familiar g/dL units used for Hb. For example, a PCV of 45% estimates Hb as about 15 g/dL. The other units listed—mg/dL, mmol/L, or g/L—aren’t the standard units produced by this quick estimate, since the practical conversion from hematocrit to Hb with this rule yields g/dL.