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Maximum Allowable Blood Loss (ABL) Without Transfusion

Calculators  Hematology
Maximum Allowable Blood Loss (ABL) Without Transfusion is practical tool utilized to measure the maximum blood loss during surgery
Adult man 75
Adult woman 65
Infant 80
Neonate 85
Premature neonate 96.01
Hemoglobin (initial)
Hemoglobin (final)
Lowest acceptable hemoglobin, by clinical judgment


Measured Factor
Maximum Allowable Blood Loss (ABL) Without Transfusion
Measured Factor Disease
  • Hemorrhage
Measured Factor Detail
Maximum Allowable Blood Loss (ABL) Without Transfusion is used to measure the maximum blood loss intraoperatively before transfusion. It helps for determining when to transfuse a patient. The calculation takes into account patient features such as age of patient, weight and Hemoglobin (initial or final).
Body System
ABL = [EBV x (Hi-Hf)]/Hi, where EBV = body wt (kg) x average blood volume (mL/kg)
Measured Factor Low Impact
  • Hemoglobin concentration values >10 g/dL illustrates the patient is on low risk and rarely require transfusion
Measured Factor High Impact
  • Hemoglobin concentration values 6-10 g/dL indicates the moderate risk condition and transfusion is based on clinical status evaluation
  • Hemoglobin concentrations values <6 g/dL illustrates high risk and the patient always require transfusion

Result Interpretation

Ranges Ranges
  • Critical Low: <6
  • Normal: >10
  • Normal Adult Male: 6-10
  • Normal Adult Female: 6-10
  • Normal Pediatric: 6-10
  • Normal Geriatric Male: 6-10
  • Normal Geriatric Female: 6-10
Result High Conditions
  • Hemorrhage


  1. Practice Guidelines for blood component therapy: A report by the American Society of Anesthesiologists Task Force on Blood Component Therapy. Anesthesiology. 1996;84(3):732-47.

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