Anaesthesiology
Maximum Allowable Blood Loss calculator
Enter the published formula inputs below to calculate and interpret this score.
Clinical inputs
Allowed range: 1–1000000 mL
Enter the blood volume in mL. The printed infant example uses 75 mL/kg times 6.0 kg, which is 450 mL.
Allowed range: 0.01–1 fraction
Enter hematocrit as a percent. The partner unit is a fraction.
Allowed range: 0.01–1 fraction
Enter hematocrit as a percent. The partner unit is a fraction.
Result
3 fields remaining
Anyone can run this calculator. Sign in to save, favourite, or send the result.
Ruqelo is AI and can make mistakes. Check important information.
Clinical inputs
- Estimated blood volume (mL)Accepted range: 1 to 1000000
- Initial hematocrit (%)Accepted range: 1 to 100
- Threshold hematocrit (%)Accepted range: 1 to 100
Primary source
Gross JB. Estimating allowable blood loss: corrected for dilution. Anesthesiology. DOI: 10.1097/00000542-198303000-00016. PMID: 6829965. The algebra was read from Breglio AM, Eck JB, Allowable Blood Loss, Society for Pediatric Anesthesia Question of the Week, accepted 18 November 2023 (https://pedsanesthesia.org/wp-content/uploads/2024/01/Week-176-Allowable-Blood-Loss-REV.pdf): allowable loss in mL equals estimated blood volume times (initial hematocrit minus threshold hematocrit) divided by the average of those two hematocrits. Gibon E et al., Int Orthop 2013, PMID 23385607, names that average as the initial and the minimum allowable hematocrit in the Gross formula. The same pediatric question prints a worked result of 237 mL for hematocrits 36% and 21% with a blood volume of 75 mL/kg in a 6.0 kg infant (450 mL). A threshold at or above the initial hematocrit has no positive allowable loss. (1983)
View source