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Maximum allowable blood loss

Estimated blood volume and the allowable loss before reaching a target hematocrit, from patient category, weight, and starting and target hematocrit.

kg
%
%
Enter weight and both hematocrit values, with the target at or below the initial value, to see the estimate.

Formula

  • EBV (mL) = blood volume per kg x weight (kg)
  • MABL (mL) = EBV x (initial Hct - target Hct) / initial Hct

Source

  • Estimated blood volumes per standard pediatric/adult references (e.g. Miller's Anesthesia).

Clinical reference only. Verify independently; clinical judgment governs.