Estimates the volume of packed red blood cells (pRBCs) and number of units required to raise hemoglobin to a target level. Based on estimated blood volume (Nadler formula) and average hemoglobin content of stored pRBC units (~22 g/dL).
Target hemoglobin must be higher than current hemoglobin. No transfusion indicated by this calculation.
Estimated Blood Volume
Volume to Transfuse
Expected Hgb After Transfusion
Units pRBC Needed
Transfusion Thresholds
Clinical Setting
Hgb Threshold
Notes
ICU (stable)
<7 g/dL
Restrictive transfusion strategy
Non-ICU (stable)
<8 g/dL
—
Cardiac surgery
<8–9 g/dL
Higher threshold in ACS
Active bleeding
Individualize
Based on symptoms and hemodynamics
Formula
EBV (Nadler) — Male: 0.3669×H³ + 0.03219×W + 0.6041 Volume to transfuse = EBV × (Target Hgb − Current Hgb) / Hgb_pRBC Units = Volume / Volume per unit Hgb_pRBC assumed = 22 g/dL
For educational use only. Clinical decisions must incorporate full patient evaluation.
