Abstract
Objectives
Although dehydration can affect mental and physical health, there is no clear, consistent,
and reproducible diagnostic tool for this condition in older people. We applied multiple
methods to detect dehydration with the aim of assessing the value of using urine analysis
for this purpose.
Design
Nonrandomized cohort study.
Setting and participants
Sixty nursing home residents, aged 64-103 (mean 84) years.
Methods
Sampling of morning urine, blood analyses, and clinical examination. A previously
validated algorithm summarized the urine specific gravity, osmolality, creatinine,
and color to a Fluid Retention Index (FRI).
Results
The cut-off for renal fluid conservation consistent with dehydration (FRI ≥ 4.0) was
reached by 51% of the cohort. No statistically significant linear correlation was
found between FRI and serum osmolality (mean 307.5 mOsmol/kg) or plasma sodium (mean
139 mmol/L), but the subjects reported less thirst with increasing FRI scores (linear
correlation r = −0.35; P < .03). Clinical examinations of mucous membranes and tongue furrows did not correlate
with other markers of dehydration. Subjects with sunken eyes had higher C-reactive
protein (P < .02) and lower albumin (P < .002) concentrations in plasma than the others, while impaired skin turgor only
correlated with age (P < .04).
Conclusions/implications
Renal fluid conservation consistent with dehydration was found in half of the nursing
home residents, which could partially be accounted for by decreased thirst. Clinical
examinations probably reflected the physical status and age more than dehydration.
The lack of correlation between the serum osmolality and the FRI, both of which are
purported to be gold standards for dehydration, raises questions about whether a gold
standard exists.
Keywords
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Article info
Publication history
Published online: September 15, 2018
Footnotes
The study was funded by the Stockholm County Council, Sweden (grant number 20120575).
The authors declare no conflicts of interest.
Identification
Copyright
© 2018 AMDA - The Society for Post-Acute and Long-Term Care Medicine.
