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The fluid management calculator calculates based upon patient demographic information provided in the fields above. Some calculations require additional patient data, for which fields are provided within the calculation. As with all clinical decision support tools, ultimately use clinical judgement when considering these results.

• Some calculations may have important additional information which can be shown using the question mark icon

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The fluid management calculator is powered by the patients, weightCalculations, and fluidManagement modules.

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(Show all categories)Fluid management

Fluid management

Estimated blood volume

Weight, Age required

• Preterm: 95 mL/kg
• 0-1 month old: 85 mL/kg
• 1 month-1 year old: 80 mL/kg
• ≥ 1 year old
  • Female: 65 mL/kg
  • Male: 75 mL/kg

1. Morgan & Mikhail's Clinical Anesthesiology. 5e. p1168

Fluid maintenance rate

Weight required

Uses 4-2-1 rule:

• 4 mL/kg for the first 10 kg
• 2 mL/kg for the next 10 kg
• 1 mL/kg for the remaining weight

1. Miller's Anesthesia 7e, section IV, pg. 1728

Intraoperative fluid dosing

Time spent NPO

hr

Severity of surgical traumaMinimalModerateSevere

Weight required

1. Corcoran T, Rhodes JE, Clarke S, Myles PS, Ho KM. Perioperative fluid management strategies in major surgery: a stratified meta-analysis. Anesth Analg. 2012 Mar;114(3):640-51. doi: 10.1213/ANE.0b013e318240d6eb. Epub 2012 Jan 16. PMID: 22253274.

Maximum allowable blood loss

Current hematocrit/hemoglobin

%g/dL

Minimum hematocrit/hemoglobin

%g/dL

Weight, Age required

1. Morgan & Mikhail's Clinical Anesthesiology. 5e. p1168

Minimum urine output

Case duration

hrmin

Weight, Age required

1. Klahr S, Miller SB. Acute oliguria. N Engl J Med. 1998 Mar 5;338(10):671-5. doi: 10.1056/NEJM199803053381007. PMID: 9486997.
2. Arant BS Jr. Postnatal development of renal function during the first year of life. Pediatr Nephrol. 1987 Jul;1(3):308-13. doi: 10.1007/BF00849229. PMID: 3153294.