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    Organ System


    Patent Pending

    Maximum Allowable Blood Loss (ABL) Without Transfusion

    Estimates the maximum allowable blood loss intraoperatively before transfusion should be considered.
    When to Use
    Why Use

    Patients with blood loss, typically during surgery, who may need transfusion.

    • The Maximum Allowable Blood Loss Without Transfusion calculator suggests how much blood can be lost, typically during surgery, before transfusion should be considered.
    • Transfusion triggers vary by patient and clinical presentation.
    • Patients with hemoglobin concentrations below 6 g/dL almost always require transfusion. In stable patients with hemoglobin values 6-10 g/dL, the decision whether to transfuse is based on an evaluation of clinical status; patients with values above 10 g/dL rarely require transfusion unless they are unstable or have signs/symptoms consistent with continued hemorrhage.

    Point to Keep in Mind

    • Gross in 1983 showed that a blood loss greater than 20% of estimated blood volume will cause the maximum allowable value to be inaccurate.

    Helps with determining when to transfuse a patient if blood count values are not immediately available.

    Adult man
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    Premature neonate


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    Creator Insights
    Dr. Jeffrey B. Gross

    About the Creator

    Jeffrey B. Gross, MD, is a professor of medicine and and chair of the department of anesthesiology at the the University of Connecticut. He is currently the chairman of the Task Force on Perioperative Management of Patients with Obstructive Sleep Apnea for the American Society of Anesthesiologists. Dr. Gross is an active researcher investigating novel methods in management in anesthesia.

    To view Dr. Jeffrey B. Gross's publications, visit PubMed

    Are you Dr. Jeffrey B. Gross? Send us a message to review your photo and bio, and find out how to submit Creator Insights!
    MDCalc loves calculator creators – researchers who, through intelligent and often complex methods, discover tools that describe scientific facts that can then be applied in practice. These are real scientific discoveries about the nature of the human body, which can be invaluable to physicians taking care of patients.
    Content Contributors
    • Amit Patel, MD
    About the Creator
    Dr. Jeffrey B. Gross
    Are you Dr. Jeffrey B. Gross?
    Content Contributors
    • Amit Patel, MD