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Updated: May 20, 2026
05:09
Long-Term Continuous Measurement of Renal Blood Flow in Conscious Rats
Published on: February 8, 2022
Minute-to-minute urine flow rate variability: a new renal physiology variable
Yoram Klein1, Mor Grinstein, Stephen M Cohn
1Department of Acute Care Surgery and Trauma, Kaplan Medical Center, Rehovot, Israel.
Anesthesia and Analgesia
|July 6, 2012
Summary
Minute-to-minute urine flow rate (UFR) variability disappears during hypovolemia. This UFR variability decrease can aid in diagnosing blood volume depletion.
Area of Science:
- Physiology
- Medical Monitoring
Background:
- Urine output is a key indicator of tissue perfusion.
- Traditional hourly urine output measurements are prone to significant errors.
- Digital urine meters offer precise minute-to-minute urine flow rate (UFR) monitoring.
Purpose of the Study:
- To characterize minute-to-minute UFR variability as a novel physiological parameter.
- To investigate the relationship between UFR variability and blood volume depletion.
Main Methods:
- Seven adult pigs were studied under euvolemic and hemorrhaging conditions (10%, 20%, 30% blood volume loss).
- Measurements included UFR, minute-to-minute UFR, mean arterial blood pressure, heart rate, and base excess.
- Variance and wavelet spectral analysis quantified UFR variability changes.
Main Results:
- UFR significantly decreased with blood loss, from 2.2 to 1.0 mL/min after 10% volume loss (P=0.0348).
- Minute-to-minute UFR variability also significantly reduced, from 1.4 to 0.4 mL/min (P=0.046).
Conclusions:
- Both UFR and its minute-to-minute variability diminish during hemorrhage.
- UFR variability shows potential as a diagnostic aid for hypovolemia.
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