Dipstick measurements of urine specific gravity are unreliable.
- de Buys Roessingh AS Renal Unit, Department of Paediatrics, University Medical Centre (CHUV), CH-1011 Lausanne, Switzerland.
- Drukker A
- Guignard JP
- 2001-07-24
Published in:
- Archives of disease in childhood. - 2001
Humans
Hydrogen-Ion Concentration
Osmolar Concentration
Point-of-Care Systems
Reagent Kits, Diagnostic
Refractometry
Reproducibility of Results
Specific Gravity
Urinalysis
English
AIM
To evaluate the reliability of dipstick measurements of urine specific gravity (U-SG).
METHODS
Fresh urine specimens were tested for urine pH and osmolality (U-pH, U-Osm) by a pH meter and an osmometer, and for U-SG by three different methods (refractometry, automatic readout of a dipstick (Clinitek-50), and (visual) change of colour of the dipstick).
RESULTS
The correlations between the visual U-SG dipstick measurements and U-SG determined by a refractometer and the comparison of Clinitek((R))-50 dipstick U-SG measurements with U-Osm were less than optimal, showing very wide scatter of values. Only the U-SG refractometer values and U-Osm had a good linear correlation. The tested dipstick was unreliable for the bedside determination of U-SG, even after correction for U-pH, as recommended by the manufacturer.
CONCLUSIONS
Among the bedside determinations, only refractometry gives reliable U-SG results. Dipstick U-SG measurements should be abandoned.
To evaluate the reliability of dipstick measurements of urine specific gravity (U-SG).
METHODS
Fresh urine specimens were tested for urine pH and osmolality (U-pH, U-Osm) by a pH meter and an osmometer, and for U-SG by three different methods (refractometry, automatic readout of a dipstick (Clinitek-50), and (visual) change of colour of the dipstick).
RESULTS
The correlations between the visual U-SG dipstick measurements and U-SG determined by a refractometer and the comparison of Clinitek((R))-50 dipstick U-SG measurements with U-Osm were less than optimal, showing very wide scatter of values. Only the U-SG refractometer values and U-Osm had a good linear correlation. The tested dipstick was unreliable for the bedside determination of U-SG, even after correction for U-pH, as recommended by the manufacturer.
CONCLUSIONS
Among the bedside determinations, only refractometry gives reliable U-SG results. Dipstick U-SG measurements should be abandoned.
- Language
-
- English
- Open access status
- bronze
- Identifiers
-
- DOI 10.1136/adc.85.2.155
- PMID 11466191
- Persistent URL
- https://folia.unifr.ch/global/documents/93557
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