Anemia from acute hemorrhage requires ____ for increased plasma volume with resulting decrease in Hgb, Hct, RBC count.

• A. 12-24 hours
• B. 1-4 hours
• C. 2-3 days
• D. 1-2 weeks

Answer: (B)

Hemodilution after acute hemorrhage is driven by rapid fluid movement from the interstitial space into the intravascular compartment, restoring plasma volume to support perfusion. This quick plasma-volume expansion occurs within hours, so the circulating hemoglobin concentration, hematocrit, and RBC count fall due to dilution even though the total RBC mass is still reduced from blood loss. The timing best matching this acute dilution is about 1–4 hours after the bleed. Waiting longer (12–24 hours or more) would reflect additional compensatory changes, not the immediate dilution that's being tested.