[Evaluation of the lithogenic risk in renal lithiasis. Value of urine density measurement]. / Evaluation du risque lithogène dans la lithiase rénale. Intérêt de la mesure de la densité urinaire.
Presse Med
; 24(33): 1559-62, 1995 Nov 04.
Article
em Fr
| MEDLINE
| ID: mdl-8539215
ABSTRACT
OBJECTIVE:
Measuring specific gravity of urine is a simple means of self-monitoring for urolithiasis patients.METHODS:
We evaluated the reliability of two test strips (N-Multistix and Combur-Stix) and determined the relationship between urine specific gravity and crystal formation in first morning urine in 179 patients with calcium oxalate lithiasis. Urine hydrometry was used as the reference method.RESULTS:
There was a good correlation between urine density read on the test strips and hydrometry (r = 0.733 for N-Multistix and 0.697 for Combur-Stix). Hydrometry showed little pH effect but the test strips gave results correlated with urine pH (r = 0.764 and 0.813 respectively). When urine pH was below 6.5, the specific gravity of the urine was overestimated; inversely for pH > 7, it was underestimated. Correction factors were obtained by comparing test strip values with specific gravity measurements for pH level between 4.5 and 8. There were crystals in 66% of the urine samples with a density > or = 1012 g/l. In contrast, 75% of the samples below this value were crystal free. There was a close relationship between 24-hour urine volume and specific gravity (n = 124; r = 0.778) a specific gravity of 1.012 corresponded to 2100 ml urine output. For 24% of the patients, specific gravity of the morning urine was > or = 1.012 despite a 24-h urine output > or = 2100 ml, indicating insufficient urine dilution during the night.CONCLUSION:
Measurement of specific gravity with test strips with correction for pH can be a simple way to measure the specific gravity of urine and assess whether urine dilution is sufficient to reduce the risk of crystal formation, the main risk factor in urolithiasis patients.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fitas Reagentes
/
Cálculos Renais
Tipo de estudo:
Diagnostic_studies
/
Etiology_studies
/
Risk_factors_studies
Limite:
Humans
Idioma:
Fr
Revista:
Presse Med
Ano de publicação:
1995
Tipo de documento:
Article