Dr. med. Dirk Manski

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24-Hour Urine: Normal Values and Creatinine Clearance Calculation

Indications for a 24-Hour Urine Collection

24-Hour Urine: Standard Values

24-hour urine: standard values.
Substance Standard value
Urinary pH 4,4–7,5
Specific Gravity 1,010–1,024 g/ml
Osmolality 500–800 mosm/kg
Urea 20–35 g/24 h
Calcium <7,5 mmol/24 h
Uric acid 0,3–0,6 g/24 h
Sodium 40–140 mmol/l
Potassium 40–120 mmol/l
Magnesium 4–8 mmol/l
Chloride 40–140 mmol/l
Protein < 150–300 mg/24 h
Cortisol < 100 mg/1,73m2/24 h
Aldosterone < 30 μg/24 h
Vanillylmandelic acid < 6,5 mg/24 h
Metanephrines < 0,8 mg/24 h

Calculation of the Creatine Clearance

The concentration of creatinine is measured in the urine from the 24 h urine test (Ucrea in mg/dl) and in the serum (Screa in mg/dl). In addition, the urine volume (Uvol in ml) is measured with the collection period (24 h = 1440 min). The creatinine clearance (Clcrea) can be calculated using the following formula:

Creatinine clearance (ml/min) = (Ucrea × Uvol)/(Screa × 1440)

Cockroft and Gault Formula for Creatinine Clearance

An estimation of the creatine clearance (after Cockroft and Gault) is possible with serum concentration (mg/dl), sex (factor F=72 for men and F=85 for women), weight (kg), and age (years) using the following formula:

GFR = -(140-age)×weight / (F× Screa)

Urine culture Index Examinations

Index: 1–9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z


D. W. Cockcroft and M. H. Gault, “Prediction of creatinine clearance from serum creatinine.,” Nephron, vol. 16, no. 1, pp. 31–41, 1976.

  Deutsche Version: 24 h-Urin