Urine Output and Fluid Balance
Urine Output
kg
mL
hours
Result:
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–
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Calculates urine output over a 24-hour period.
Formula
Urine output [cc/kg/hr] = Actual[cc/day] / (weight [kg]*24)
Pearls / Pitfalls
Calculates urine output rate and fluid balance, comparing with normals, from total urine output and fluid intake.
Advice
Can be used to measure fluid balance as well as possible kidney injury. The RIFLE Criteria provide one method of stratifying acute kidney injury. When assessing fluid status, remember to consider insensible losses (~400 mL/day in adults) and endogenous water.
More Information
The normal range for 24-hour urine volume is 800 to 2000 milliliters per day (with a normal fluid intake of about 2 liters per day). Oliguria is urine output < 500 mL in 24 h (0.5 mL/kg/h) in an adult. Oliguria is urine output < 1 L in 24 h (1 mL/kg/h) in a child.