- During blood loss, dilution of remaining hemoglobin occurs as intravascular volume is maintained by fluid shifts and administration of fluids.
- Consider transfusing if estimated blood loss exceeds calculated allowable blood loss.
- Estimating blood loss intraoperatively can be done via direct measure of blood in suction canister along with measuring soiled sponges.
- This method is only an estimate to measure blood loss. Patient vitals and clinical signs should be evaluated clinically first.
- Capacity by sponge type:
- 4x4s: ~10 mL blood
- Gauze sponges (Ray-Tec):~10-20 mL blood
- Laparotomy (lap) sponges: ~50-100 mL blood
- Consider timing of blood loss. Acute blood loss may not present with a drop in hemoglobin. Always monitor clinical metrics such as hemodynamics and respiratory status along with anticipated blood loss.
- The trigger to transfuse varies by patient.
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- Amit Patel, MD