Monitoring hydration status in elderly veterans

Integration of a new technology into a work system: a case study of a smart drinking glass in French nursing homes

PURPOSE

To reduce the risk of dehydration in older adults, the French company Auxivia has developed a smart drinking glass (SDG) that can measure the amount of water drunk. The present study looked at the various work systems (WSs) designed for use of the SDG in a nursing home. The study's objectives were to (i) determine the WSs' impact on the staff's ability to comply with the device's prerequisites and ensure the device's effective use and (ii) draw up guidelines on designing work systems.

MATERIALS AND METHODS

At three nursing homes in France, two independent observers performed 9 h of observations at each site and a total of 29 interviews.

RESULTS

Decisions concerning implementation and the resulting WSs have an impact on the tasks to be performed, the tasks' inherent constraints and the use of the SDG. It is essential to take account of the sociotechnical system as a whole before integrating a technology. Ideally, the introduction of an SDG will go unnoticed by staff and residents; however, our results emphasize the value of highlighting work constraints via a human factors analysis.

CONCLUSIONS

It is essential to take account of sociotechnical WSs as a whole when integrating a technology.

Hydration Status Assessment in Older Patients

BACKGROUND

Hydration disturbances are common in old age: the reported prevalence of dehydration in elderly patients ranges from 19% to 89%, depending on the definition and the population in question. However, the clinical assessment of patients' hydration status is difficult. In this review, we discuss the diagnostic value of currently used methods that may or may not be suitable for assessing older patients' hydration status.

METHODS

We conducted a selective literature search for relevant studies concerning patients aged 65 and above. Of the 355 articles retrieved by the initial search, a multistep selection process yielded 30 that were suitable for inclusion in this review.

RESULTS

107 different methods for the diagnostic assessment of dehydration in older persons were evaluated on the basis of the reviewed publications. High diagnostic value, especially for the determination of hyperosmolar dehydration, was found for serum osmolality, serum sodium concentration, inferior vena cava ultrasonography, a history (from the patient or another informant) of not drinking between meals, and axillary dryness. On the other hand, a variety of clinical signs such as a positive skin turgor test, sunken eyes, dry mouth, tachycardia, orthostatic dysregulation, and dark urine were found to be of inadequate diagnostic value.

CONCLUSION

Only five of the 107 methods considered appear to be suitable for determining that a patient is dehydrated. Thus, the available scientific evidence indicates that all clinicians should critically reconsider their own techniques for assessing hydration status in elderly patients. To optimize the clinical assessment of patients' hydration status, there seems to be a need for the rejection of unsuitable methods in favor of either newly developed criteria or of a combination of the best criteria already in use.

Fluid Intake Monitoring Systems for the Elderly: A Review of the Literature

Fluid intake monitoring is an essential component in preventing dehydration and overhydration, especially for the senior population. Numerous critical health problems are associated with poor or excessive drinking such as swelling of the brain and heart failure. Real-time systems for monitoring fluid intake will not only measure the exact amount consumed by the users, but could also motivate people to maintain a healthy lifestyle by providing feedback to encourage them to hydrate regularly throughout the day. This paper reviews the most recent solutions to automatic fluid intake monitoring both commercially and in the literature. The available technologies are divided into four categories: wearables, surfaces with embedded sensors, vision- and environmental-based solutions, and smart containers. A detailed performance evaluation was carried out considering detection accuracy, usability and availability. It was observed that the most promising results came from studies that used data fusion from multiple technologies, compared to using an individual technology. The areas that need further research and the challenges for each category are discussed in detail.

Fluid Needs in the Older Adult Receiving Tube Feedings

Fluid imbalance can occur quickly in older adults and in others who cannot express thirst or are in a setting where fluid status is not closely monitored. In tube-fed individuals receiving inadequate calories, severe malnutrition may occur in weeks to months, but improper water intake may lead to critical fluid imbalances in a matter of days. Simplistic equations frequently used to determine fluid needs in adults include milliliters per kilogram of body weight and milliliters per energy (kilocalories) consumed or per energy (kilocalories) need and variations of the Holliday-Segar formula. None of these fluid-requirement equations have been validated through evidenced-based science, and research investigations have revealed that they can grossly overestimate or underestimate fluid needs in the older adult. Clinicians need guidance to better estimate initial fluid needs for the older adult receiving tube feedings and to provide proper close monitoring afterward to avert preventable fluid imbalance-related hospital readmissions, morbidities, and mortalities in this patient population.

[Analysis of dehydration in older people in a nursing home in Spain: prevalence and associated factors]

Introduction

Background: dehydration in institutionalized elderly people has not been extensively studied. There are not clear data on the Spanish context. Aim: to estimate the prevalence of dehydration and to identify the associated factors in institutionalized older people in a nursing home. Methods: a cross-sectional study was carried out. Dehydration was measured through the colour of urine. For the identification of the associated factors, sociodemographic, clinical, functional, and mental variables were selected. Results: the total sample studied was comprised of 96 individuals with a mean age of 86.6 years (± 7.1), of whom 80.2 % were women. The prevalence of dehydration was 31.3% (95 % CI, 22.0 to 40.6). The factors that were independently associated with dehydration were the presence of sunken eyes (OR = 8.67; p = 0.004), low fluid intake (OR = 3.96; p = 0.041), and both functional (OR = 0.97; p = 0.012) and cognitive (OR = 1.10; p = 0.009) impairment. Conclusions: this study highlights the problem of dehydration in institutionalized older people in Spain. An urine colour table may be used routinely, non-invasively, and cheaply. So, it may well be the best simple method for detecting dehydration in this population. Taking into account that chronic dehydration is most prevalent in elderly people, the identification of associated factors is a key factor for a successful approach.

Fluid Intake Recommendation Considering the Physiological Adaptations of Adults Over 65 Years: A Critical Review

The aim of this critical review was to clarify recommended fluid intake for older people. A literature search of published articles and guidelines on fluid intake recommendations until April 2020 was carried out using PUBMED, Scopus, Cochrane, and Google Scholar. In this review, we focused on people over 65 years old at different care levels. The results show that the mean fluid intake ranges between 311 and 2390 mL/day. However, it is difficult to know whether this corresponds to the real pattern of fluid intake, due to the variability of data collection methods. With respect to the recommendations, most international organizations do not take into consideration the physiology of ageing or the health problems associated with an older population. In conclusions, we recommend to follow the guideline of the European Society for Clinical Nutrition and Metabolism (ESPEN) and the European Food Safety Authority (EFSA). ESPEN is the only guideline which takes into account age. It is also based on EFSA recommendations. This authority takes into consideration all fluids consumed (ranging from food to fluids). If it is known that around 20% of all fluids consumed come from food, the result would effectively be that the EFSA recommends the same as the ESPEN guidelines: 1.6 L/day for females and 2.0 L/day for males. The findings could help raise the awareness of professionals in the sector with respect to the required fluid intake of the elderly and, in this way, contribute to avoiding the consequences of dehydration.

Prevalence of cerebral venous thrombosis with the use of oral contraceptive pills during the Holy month of Ramadan

Objectives:

To identify the epidemiologic profile of cerebral vein thrombosis (CVT) among fasting women using oral contraceptive pills (OCPs) during the holy month of Ramadan.

Methods:

This retrospective study was conducted on all patients diagnosed with CVT and using OCPs from records at a tertiary care hospital in Riyadh, Saudi Arabia during 2016-2017. The study participants were categorized into 2 groups (an intermittently fasting group during the holy month of Ramadan and a non-fasting group).

Results:

Out of 108 female patients with CVT, 36.1% were secondary to OCP, of whom 41% participants were fasting. The most affected site was the transverse sinus. Holocephalic headache was more common amongst fasting group (68.8%) compared to non-fasting group (30.4%) (p=0.025). Dehydration (p=0.003) amongst the fasting group and protein S deficiency (p=0.027) in the non-fasting group were identified as the 2 prominent risk factors. Unfractionated heparin was the most common anticoagulant therapies used during the initiation phase for non-fasting (36.4%) and fasting groups (50%).

Conclusion:

All women who are using OCP should undergo formal written risk assessments for factors of CVT. Our study suggests that the negative effects of OCPs use might outweigh its benefits; thus, it should be prescribed with caution, more so in fasting patients.

Assessing dehydration status in dengue patients using urine colourimetry and mobile phone technology

Background

Dengue is a systemic and dynamic disease with symptoms ranging from undifferentiated fever to dengue shock syndrome. Assessment of patients’ severity of dehydration is integral to appropriate care and management. Urine colour has been shown to have a high correlation with overall assessment of hydration status. This study tests the feasibility of measuring dehydration severity in dengue fever patients by comparing urine colour captured by mobile phone cameras to established laboratory parameters.

Methodology/Principal findings

Photos of urine samples were taken in a customized photo booth, then processed using Adobe Photoshop to index urine colour into the red, green, and blue (RGB) colour space and assigned a unique RGB value. The RGB values were then correlated with patients’ clinical and laboratory hydration indices using Pearson’s correlation and multiple linear regression. There were strong correlations between urine osmolality and the RGB of urine colour, with r = -0.701 (red), r = -0.741 (green), and r = -0.761 (blue) (all p-value <0.05). There were strong correlations between urine specific gravity and the RGB of urine colour, with r = -0.759 (red), r = -0.785 (green), and r = -0.820 (blue) (all p-value <0.05). The blue component had the highest correlations with urine specific gravity and urine osmolality. There were moderate correlations between RGB components and serum urea, at r = -0.338 (red), -0.329 (green), -0.360 (blue). In terms of urine biochemical parameters linked to dehydration, multiple linear regression studies showed that the green colourimetry code was predictive of urine osmolality (β coefficient -0.082, p-value <0.001) while the blue colourimetry code was predictive of urine specific gravity (β coefficient -2,946.255, p-value 0.007).

Conclusions/Significance

Urine colourimetry using mobile phones was highly correlated with the hydration status of dengue patients, making it a potentially useful hydration status tool.

The vast majority of symptomatic dengue infections will result in an uncomplicated disease course. A small proportion will develop severe dengue late in the course of disease, on about day 4 or 5 of illness. In the absence of early prognostic markers to triage dengue patients for early supportive intervention, all suspected dengue cases are followed up for daily assessment, which includes an assessment of dehydration. While the clinical assessment of dehydration is subjective, the passing of dark-coloured urine is an accepted indicator of dehydration. However, visual assessment of urine colour is limited by the varied perception of colour and ambient lighting. An objective method to assess urine colour is to encode it in the RGB model. We used a mobile phone to capture an image of urine samples under standardised conditions and computed the RGB value of each image. Our study demonstrated that RGB urine colourimetry using mobile phones is highly correlated with the hydration status of dengue patients, making it a hydration status tool of great potential.

Clinical utility of urine specific gravity, electrical conductivity, and color as on-farm methods for evaluating urine concentration in dairy cattle

Background

Urine concentration (UC) provides clinically useful information concerning hydration status and renal function of animals.

Objectives

To characterize the clinical performance of urine specific gravity measured by optical refractometry (U_SG‐R) or Multistix‐SG urine reagent dipstick (U_SG‐D), urine electrical conductivity using an OAKTON Con 6 conductivity handheld meter (U_EC), urine color (U_Color) using a custom‐designed 8‐point color chart, and urine creatinine concentration (U_Creat) for assessing UC in dairy cattle.

Animals

20 periparturient Holstein‐Friesian cows.

Methods

Urine was obtained by perineal stimulation or urethral catheterization and urine osmolality (U_Osm, reference method), U_SG‐R, U_SG‐D, U_EC, U_Color, and U_Creat determined. Diagnostic test performance was evaluated using Spearman's rho and logistic regression to determine the area under the receiver operating curve (AUC) and optimal cut point for diagnosing hypohydration (U_Osm ≥800 mOsm/kg). P < .05 was considered significant.

Results

The best performing test for diagnosing hypohydration was U_SG‐R (AUC = 0.90) at an optimal cut point ≥1.030. The second‐best performing test was U_EC (AUC = 0.82) at a cut point of ≥23.7 mS/cm, followed by U_Creat (AUC = 0.76) at a cut point of ≥95.3 mg/dL, and U_Color (AUC = 0.74) at a cut point of ≥4 on an 8‐point scale. Urine specific gravity measured by dipstick performed poorly (AUC = 0.63).

Conclusions and Clinical Importance

U_SG‐R and U_EC provide practical and sufficiently accurate methods for measuring UC in dairy cattle. Urine color had moderate clinical utility as a no‐cost cow‐side method for assessing UC, whereas dipstick refractometry is not recommended for assessing UC.

Engineering Approaches to Assessing Hydration Status

Dehydration is a common condition characterized by a decrease in total body water. Acute dehydration can cause physical and cognitive impairment, heat stroke and exhaustion, and, if severe and uncorrected, even death. The health effects of chronic mild dehydration are less well studied with urolithiasis (kidney stones) the only condition consistently associated with it. Aside from infants and those with particular medical conditions, athletes, military personnel, manual workers, and older adults are at particular risk of dehydration due to their physical activity, environmental exposure, and/or challenges in maintaining fluid homeostasis. This review describes the different approaches that have been explored for hydration assessment in adults. These include clinical indicators perceived by the patient or detected by a practitioner and routine laboratory analyses of blood and urine. These techniques have variable accuracy and practicality outside of controlled environments, creating a need for simple, portable, and rapid hydration monitoring devices. We review the wide array of devices proposed for hydration assessment based on optical, electromagnetic, chemical, and acoustical properties of tissue and bodily fluids. However, none of these approaches has yet emerged as a reliable indicator in diverse populations across various settings, motivating efforts to develop new methods of hydration assessment.

Use of a Urine Color Chart to Monitor Hydration Status in Nursing Home Residents

To determine whether urine color, as measured by a color chart, might be a valid indicator of hydration status in frail nursing home residents, this study tested the associations between urine color and urine specific gravity. This is a descriptive correlational study set in seven nursing homes in eastern Iowa. Ninety-eight nursing home residents 65 years of age participated. Exclusion criteria for the study included: unstable congestive heart failure or diabetes, documented renal disease, hyponatremia (serum sodium < 135 meq/L), terminal illness, acutely confused/delirious or urinary tract infection at baseline, and gastrostomy-tube dependence. Weekly urine specimens were collected. Ucol was measured first, using a urine color chart. Usg was determined using the Chemstrip Mini UA Urine Analyzer. Week-by-week Spearman rank order correlations between urine color and specific gravity for the total sample (n = 98) ranged from rs = 0.3 - 0.7, p < .01; the PROC mixed model was significant, p < .01. In subgroup analyses (n = 78), all females (rs = 0.67, p = .01) and both males (rs = 0.53, p = .01) and females (rs = 0.72, p = .01) with adequate renal function (Cockcroft-Gault estimated creatinine clearance [CrCl] values of 50 ml/min) had significant associations between average urine color and average Usg. Females with mild renal impairment (CrCl between 30 and 50 ml/min) also had significant associations between Ucol and Usg (rs = .64, p < .01). Ucol averaged over several individual readings offers another tool in assessing hydration status in Caucasian nursing home residents with ade quate renal function measures by estimated CrCl values.

Water-loss (intracellular) dehydration assessed using urinary tests: how well do they work? Diagnostic accuracy in older people

BACKGROUND

Water-loss dehydration (hypertonic, hyperosmotic, or intracellular dehydration) is due to insufficient fluid intake and is distinct from hypovolemia due to excess fluid losses. Water-loss dehydration is associated with poor health outcomes such as disability and mortality in older people. Urine specific gravity (USG), urine color, and urine osmolality have been widely advocated for screening for dehydration in older adults.

OBJECTIVE

We assessed the diagnostic accuracy of urinary measures to screen for water-loss dehydration in older people.

DESIGN

This was a diagnostic accuracy study of people aged ≥65 y taking part in the DRIE (Dehydration Recognition In our Elders; living in long-term care) or NU-AGE (Dietary Strategies for Healthy Ageing in Europe; living in the community) studies. The reference standard was serum osmolality, and index tests included USG, urine color, urine osmolality, urine cloudiness, additional dipstick measures, ability to provide a urine sample, and the volume of a random urine sample. Minimum useful diagnostic accuracy was set at sensitivity and specificity ≥70% or a receiver operating characteristic plot area under the curve ≥0.70.

RESULTS

DRIE participants (women: 67%; mean age: 86 y; n = 162) had more limited cognitive and functional abilities than did NU-AGE participants (women: 64%; mean age: 70 y; n = 151). Nineteen percent of DRIE participants and 22% of NU-AGE participants were dehydrated (serum osmolality >300 mOsm/kg). Neither USG nor any other potential urinary tests were usefully diagnostic for water-loss dehydration.

CONCLUSIONS

Although USG, urine color, and urinary osmolality have been widely advocated for screening for dehydration in older adults, we show, in the largest study to date to our knowledge, that their diagnostic accuracy is too low to be useful, and these measures should not be used to indicate hydration status in older people (either alone or as part of a wider tranche of tests). There is a need to develop simple, inexpensive, and noninvasive tools for the assessment of dehydration in older people. The DRIE study was registered at www.researchregister.org.uk as 122273. The NU-AGE trial was registered at clinicialtrials.gov as NCT01754012.

Urine color as an indicator of urine concentration in pregnant and lactating women

Aim

Urine concentration measured via osmolality (U_OSM) and specific gravity (U_SG) reflects the adequacy of daily fluid intake, which has important relationships to health in pregnant (PREG) and lactating (LACT) women. Urine color (U_COL) may be a practical, surrogate marker for whole-body hydration status.

Purpose

To determine whether U_COL was a valid measure of urine concentration in PREG and LACT, and pair-matched non-pregnant, non-lactating control women (CON).

Methods

Eighteen PREG/LACT (age 31 ± 1 years, pre-pregnancy BMI 24.3 ± 5.9 kg m⁻²) and eighteen CON (age 29 ± 4 years, BMI 24.1 ± 3.7 kg m⁻²) collected 24-h and single-urine samples on specified daily voids at five time points (15 ± 2, 26 ± 1, and 37 ± 1 weeks gestation, 3 ± 1 and 9 ± 1 weeks postpartum during lactation; CON visits were separated by similar time intervals) for measurement of 24-h U_OSM, U_SG, and U_COL and single-sample U_OSM and U_COL.

Results

Twenty-four-hour U_COL was significantly correlated with 24-h U_OSM (r = 0.6085–0.8390, P < 0.0001) and 24-h U_SG (r = 0.6213–0.8985, P < 0.0001) in all groups. A 24-h U_COL ≥ 4 (AUC = 0.6848–0.9513, P < 0.05) and single-sample U_COL ≥ 4 (AUC = 0.9094–0.9216, P < 0.0001) indicated 24-h U_OSM ≥ 500 mOsm kg⁻¹ (representing inadequate fluid intake) in PREG, LACT, and CON.

Conclusions

Urine color was a valid marker of urine concentration in all groups. Thus, PREG, LACT, and CON can utilize U_COL to monitor their daily fluid balance. Women who present with a U_COL ≥ 4 likely have a U_OSM ≥ 500 mOsm kg⁻¹ and should increase fluid consumption to improve overall hydration status.

Quantification of chromatographic effects of vitamin B supplementation in urine and implications for hydration assessment

Changes in body water elicit reflex adjustments at the kidney, thus maintaining fluid volume homeostasis. These renal adjustments change the concentration and color of urine, variables that can, in turn, be used as biomarkers of hydration status. It has been suggested that vitamin supplementation alters urine color; it is unclear whether any such alteration would confound hydration assessment via colorimetric evaluation. We tested the hypothesis that overnight vitamin B2 and/or B12 supplementation alters urine color as a marker of hydration status. Thirty healthy volunteers were monitored during a 3-day euhydrated baseline, confirmed via first morning nude body mass, urine specific gravity, and urine osmolality. Volunteers then randomly received B2 ( n = 10), B12 ( n = 10), or B2 + B12 ( n = 10) at ∼200 × recommended dietary allowance. Euhydration was verified on trial days (two of the following: body mass ± 1.0% of the mean of visits 1–3, urine specific gravity < 1.02, urine osmolality < 700 mmol/kg). Vitamin purity and urinary B2 concentration ([B2]) and [B12] were quantified via ultraperformance liquid chromatography. Two independent observers assessed urine color using an eight-point standardized color chart. Following supplementation, urinary [B2] was elevated; however, urine color was not different between nonsupplemented and supplemented trials. For example, in the B2 trial, urinary [B2] increased from 8.6 × 104 ± 7.7 × 104 to 5.7 × 106 ± 5.3 × 106 nmol/l ( P < 0.05), and urine color went from 4 ± 1 to 5 ± 1 ( P > 0.05). Both conditions met the euhydrated color classification. We conclude that a large overnight dose of vitamins B2 and B12 does not confound assessment of euhydrated status via urine color.

Clinical symptoms, signs and tests for identification of impending and current water-loss dehydration in older people

BACKGROUND

There is evidence that water-loss dehydration is common in older people and associated with many causes of morbidity and mortality. However, it is unclear what clinical symptoms, signs and tests may be used to identify early dehydration in older people, so that support can be mobilised to improve hydration before health and well-being are compromised.

OBJECTIVES

To determine the diagnostic accuracy of state (one time), minimally invasive clinical symptoms, signs and tests to be used as screening tests for detecting water-loss dehydration in older people by systematically reviewing studies that have measured a reference standard and at least one index test in people aged 65 years and over. Water-loss dehydration was defined primarily as including everyone with either impending or current water-loss dehydration (including all those with serum osmolality ≥ 295 mOsm/kg as being dehydrated).

SEARCH METHODS

Structured search strategies were developed for MEDLINE (OvidSP), EMBASE (OvidSP), CINAHL, LILACS, DARE and HTA databases (The Cochrane Library), and the International Clinical Trials Registry Platform (ICTRP). Reference lists of included studies and identified relevant reviews were checked. Authors of included studies were contacted for details of further studies.

SELECTION CRITERIA

Titles and abstracts were scanned and all potentially relevant studies obtained in full text. Inclusion of full text studies was assessed independently in duplicate, and disagreements resolved by a third author. We wrote to authors of all studies that appeared to have collected data on at least one reference standard and at least one index test, and in at least 10 people aged ≥ 65 years, even where no comparative analysis has been published, requesting original dataset so we could create 2 x 2 tables.

DATA COLLECTION AND ANALYSIS

Diagnostic accuracy of each test was assessed against the best available reference standard for water-loss dehydration (serum or plasma osmolality cut-off ≥ 295 mOsm/kg, serum osmolarity or weight change) within each study. For each index test study data were presented in forest plots of sensitivity and specificity. The primary target condition was water-loss dehydration (including either impending or current water-loss dehydration). Secondary target conditions were intended as current (> 300 mOsm/kg) and impending (295 to 300 mOsm/kg) water-loss dehydration, but restricted to current dehydration in the final review.We conducted bivariate random-effects meta-analyses (Stata/IC, StataCorp) for index tests where there were at least four studies and study datasets could be pooled to construct sensitivity and specificity summary estimates. We assigned the same approach for index tests with continuous outcome data for each of three pre-specified cut-off points investigated.Pre-set minimum sensitivity of a useful test was 60%, minimum specificity 75%. As pre-specifying three cut-offs for each continuous test may have led to missing a cut-off with useful sensitivity and specificity, we conducted post-hoc exploratory analyses to create receiver operating characteristic (ROC) curves where there appeared some possibility of a useful cut-off missed by the original three. These analyses enabled assessment of which tests may be worth assessing in further research. A further exploratory analysis assessed the value of combining the best two index tests where each had some individual predictive ability.

MAIN RESULTS

There were few published studies of the diagnostic accuracy of state (one time), minimally invasive clinical symptoms, signs or tests to be used as screening tests for detecting water-loss dehydration in older people. Therefore, to complete this review we sought, analysed and included raw datasets that included a reference standard and an index test in people aged ≥ 65 years.We included three studies with published diagnostic accuracy data and a further 21 studies provided datasets that we analysed. We assessed 67 tests (at three cut-offs for each continuous outcome) for diagnostic accuracy of water-loss dehydration (primary target condition) and of current dehydration (secondary target condition).Only three tests showed any ability to diagnose water-loss dehydration (including both impending and current water-loss dehydration) as stand-alone tests: expressing fatigue (sensitivity 0.71 (95% CI 0.29 to 0.96), specificity 0.75 (95% CI 0.63 to 0.85), in one study with 71 participants, but two additional studies had lower sensitivity); missing drinks between meals (sensitivity 1.00 (95% CI 0.59 to 1.00), specificity 0.77 (95% CI 0.64 to 0.86), in one study with 71 participants) and BIA resistance at 50 kHz (sensitivities 1.00 (95% CI 0.48 to 1.00) and 0.71 (95% CI 0.44 to 0.90) and specificities of 1.00 (95% CI 0.69 to 1.00) and 0.80 (95% CI 0.28 to 0.99) in 15 and 22 people respectively for two studies, but with sensitivities of 0.54 (95% CI 0.25 to 0.81) and 0.69 (95% CI 0.56 to 0.79) and specificities of 0.50 (95% CI 0.16 to 0.84) and 0.19 (95% CI 0.17 to 0.21) in 21 and 1947 people respectively in two other studies). In post-hoc ROC plots drinks intake, urine osmolality and axillial moisture also showed limited diagnostic accuracy. No test was consistently useful in more than one study.Combining two tests so that an individual both missed some drinks between meals and expressed fatigue was sensitive at 0.71 (95% CI 0.29 to 0.96) and specific at 0.92 (95% CI 0.83 to 0.97).There was sufficient evidence to suggest that several stand-alone tests often used to assess dehydration in older people (including fluid intake, urine specific gravity, urine colour, urine volume, heart rate, dry mouth, feeling thirsty and BIA assessment of intracellular water or extracellular water) are not useful, and should not be relied on individually as ways of assessing presence or absence of dehydration in older people.No tests were found consistently useful in diagnosing current water-loss dehydration.

AUTHORS' CONCLUSIONS

There is limited evidence of the diagnostic utility of any individual clinical symptom, sign or test or combination of tests to indicate water-loss dehydration in older people. Individual tests should not be used in this population to indicate dehydration; they miss a high proportion of people with dehydration, and wrongly label those who are adequately hydrated.Promising tests identified by this review need to be further assessed, as do new methods in development. Combining several tests may improve diagnostic accuracy.

Assessment of hydration status in a large population

Both acute and chronic dehydration can have important implications for human behaviour and health. Young children, non-autonomous individuals and the elderly are at a greater risk of dehydration. Mild hypertonic dehydration could be related to less efficient cognitive and physical performance and has been reported to be associated with frequently occurring pathological conditions, especially nephrolithiasis. The assessment of hydration status in a large sample appears to be of interest for conducting epidemiological and large clinical studies aimed at improving preventive and curative care. Especially in large-population studies, methods that are used have to be accurate, cheap, quick and require no technical expertise. Body weight change is widely used to determine acute hydration changes, but seems to be insufficiently accurate in longitudinal studies. Bioimpedance analysis methods enable the assessment of total body water content, but their use is still under debate. Because plasma osmolality directly reflects intracellular osmolality, it constitutes a good marker to assess acute hydration changes, but not chronic hydration status because it changes constantly. Moreover, venepuncture is considered to be invasive and is not suitable for a large-sample study, especially in children. Urinary markers appear to be good alternatives for assessing hydration status in large populations. Collection of urine samples is non-invasive and cheap. High technical expertise is not required to perform urinary marker measurements and these measurements can be carried out quickly. Thus, methods based on urinary markers are very well suited for field studies. Urine colour is probably the least sensitive marker despite its high specificity. Urine osmolality and especially urine specific gravity could be easily used for determining hydration status in large-sample studies.

Is this elderly patient dehydrated? Diagnostic accuracy of hydration assessment using physical signs, urine, and saliva markers

OBJECTIVES

Dehydration in older adults contributes to increased morbidity and mortality during hospitalization. As such, early diagnosis of dehydration may improve patient outcome and reduce the burden on healthcare. This prospective study investigated the diagnostic accuracy of routinely used physical signs, and noninvasive markers of hydration in urine and saliva.

DESIGN

Prospective diagnostic accuracy study.

SETTING

Hospital acute medical care unit and emergency department.

PARTICIPANTS

One hundred thirty older adults [59 males, 71 females, mean (standard deviation) age = 78 (9) years].

MEASUREMENTS

Participants with any primary diagnosis underwent a hydration assessment within 30 minutes of admittance to hospital. Hydration assessment comprised 7 physical signs of dehydration [tachycardia (>100 bpm), low systolic blood pressure (<100 mm Hg), dry mucous membrane, dry axilla, poor skin turgor, sunken eyes, and long capillary refill time (>2 seconds)], urine color, urine specific gravity, saliva flow rate, and saliva osmolality. Plasma osmolality and the blood urea nitrogen to creatinine ratio were assessed as reference standards of hydration with 21% of participants classified with water-loss dehydration (plasma osmolality >295 mOsm/kg), 19% classified with water-and-solute-loss dehydration (blood urea nitrogen to creatinine ratio >20), and 60% classified as euhydrated.

RESULTS

All physical signs showed poor sensitivity (0%-44%) for detecting either form of dehydration, with only low systolic blood pressure demonstrating potential utility for aiding the diagnosis of water-and-solute-loss dehydration [diagnostic odds ratio (OR) = 14.7]. Neither urine color, urine specific gravity, nor saliva flow rate could discriminate hydration status (area under the receiver operating characteristic curve = 0.49-0.57, P > .05). In contrast, saliva osmolality demonstrated moderate diagnostic accuracy (area under the receiver operating characteristic curve = 0.76, P < .001) to distinguish both dehydration types (70% sensitivity, 68% specificity, OR = 5.0 (95% confidence interval 1.7-15.1) for water-loss dehydration, and 78% sensitivity, 72% specificity, OR = 8.9 (95% confidence interval 2.5-30.7) for water-and-solute-loss dehydration).

CONCLUSIONS

With the exception of low systolic blood pressure, which could aid in the specific diagnosis of water-and-solute-loss dehydration, physical signs and urine markers show little utility to determine if an elderly patient is dehydrated. Saliva osmolality demonstrated superior diagnostic accuracy compared with physical signs and urine markers, and may have utility for the assessment of both water-loss and water-and-solute-loss dehydration in older individuals. It is particularly noteworthy that saliva osmolality was able to detect water-and-solute-loss dehydration, for which a measurement of plasma osmolality would have no diagnostic utility.

Arginine vasopressin, fluid balance and exercise: is exercise-associated hyponatraemia a disorder of arginine vasopressin secretion?

The ability of the human body to regulate plasma osmolality (POsm) within a very narrow and well defined physiological range underscores the vital importance of preserving water and sodium balance at rest and during exercise. The principle endocrine regulator of whole body fluid homeostasis is the posterior pituitary hormone, arginine vasopressin (AVP). Inappropriate AVP secretion may perpetuate either slow or rapid violation of these biological boundaries, thereby promoting pathophysiology, morbidity and occasional mortality. In the resting state, AVP secretion is primarily regulated by changes in POsm (osmotic regulation). The osmotic regulation of AVP secretion during exercise, however, may possibly be enhanced or overridden by many potential non-osmotic factors concurrently stimulated during physical activity, particularly during competition. The prevalence of these highly volatile non-osmotic AVP stimuli during strenuous or prolonged physical activity may reflect a teleological mechanism to promote water conservation during exercise. However, non-osmotic AVP secretion, combined with high fluid availability plus sustained fluid intake (exceeding fluid output), has been hypothesized to lead to an increase in both the incidence and related deaths from exercise-associated hyponatraemia (EAH) in lay and military populations. Inappropriately, high plasma AVP concentrations ([AVP](p)) associated with low blood sodium concentrations facilitate fluid retention and sodium loss, thereby possibly reconciling both the water intoxication and sodium loss theories of hyponatraemia that are currently under debate. Therefore, given the potential for a variety of exercise-induced non-osmotic stimuli for AVP secretion, hydration strategies must be flexible, individualized and open to change during competitive events to prevent the occurrence of rare, but life-threatening, EAH. This review focuses on the potential osmotic and non-osmotic stimuli to AVP secretion that may affect fluid homeostasis during physical activity. Recent laboratory and field data support: (i) stimulatory effects of exercise intensity and duration on [AVP](p); (ii) possible relationships between changes in POsm with changes in both sweat and urinary osmolality; (iii) alterations in the AVP osmoregulatory set-point by sex steroid hormones; (iv) differences in [AVP](p) in trained versus untrained athletes; and (v) potential inter-relationships between AVP and classical (aldosterone, atrial natriuretic peptide) and non-classical (oxytocin, interleukin-6) endocrine mediators. The review concludes with a hypothesis on how sustained fluid intakes beyond the capacity for fluid loss might possibly facilitate the development of hyponatraemia if exercise-induced non-osmotic stimuli override 'normal' osmotic suppression of AVP when hypo-osmolality exists.

Measuring risk for dehydration in nursing home residents: evaluation of the dehydration risk appraisal checklist

The purpose of this study was to evaluate the ability of the Dehydration Risk Appraisal Checklist (DRAC) to measure dehydration risk in nursing home (NH) residents. The DRAC includes items concerning health conditions, medications, fluid intake behaviors, and laboratory abnormalities that have been identified in the literature as risk factors for dehydration. Principal component factor analysis, known group comparisons, and multiple logistic regression were used to evaluate the criterion-related validity and reliability of the DRAC. After reducing the number of items on the DRAC on the basis of a correlation matrix, a single-factor solution with moderate internal consistency was supported. Further validity analysis demonstrated that NH residents with higher urine-specific gravity scored higher than those who had lower specific gravity. The psychometric properties of the DRAC indicate that it has potential in determining dehydration risk in NH residents. Future refinement of the instrument is also discussed.

Developing a quick and practical screen to improve the identification of poor hydration in geriatric and rehabilitative care

Dehydration has been associated with increased morbidity and mortality. Dehydration risk increases with advancing age, and will progressively become an issue as the aging population increases. Worldwide, those aged 60 years and over are the fastest growing segment of the population. The study aimed to develop a clinically practical means to identify dehydration amongst older people in the clinical care setting. Older people aged 60 years or over admitted to the Geriatric and Rehabilitation Unit (GARU) of two tertiary teaching hospitals were eligible for participation in the study. Ninety potential screening questions and 38 clinical parameters were initially tested on a single sample (n = 33) with the most promising 11 parameters selected to undergo further testing in an independent group (n = 86). Of the almost 130 variables explored, tongue dryness was most strongly associated with poor hydration status, demonstrating 64% sensitivity and 62% specificity within the study participants. The result was not confounded by age, gender or body mass index. With minimal training, inter-rater repeatability was over 90%. This study identified tongue dryness as a potentially practical tool to identify dehydration risk amongst older people in the clinical care setting. Further studies to validate the potential screen in larger and varied populations of older people are required.

Risk factors and outcomes associated with hospital admission for dehydration

The hospital admission rate for dehydration is one of the Agency for Healthcare Research and Quality Prevention's Quality Indicators, which are considered screening tools for potential quality issues. Thus, admission for dehydration may reflect the quality of care provided in community settings. Using a case-control design, this study estimated the incidence, risk factors, and outcomes of dehydration in adults admitted to the hospital. The overall prevalence rate for three International Classification of Diseases codes for dehydration at admission was 0.55%. Cases and controls differed significantly on a number of clinical variables at admission, including weight, body mass index, pulse, blood pressure, use of bulk-forming laxatives, serum sodium and chloride, and presence of generalized weakness or hemiplegia, edema, diarrhea, vomiting, and having nothing by mouth before admission. Mortality rates at 30 and 180 days after discharge were not significantly different between the two groups. Dehydration in community-dwelling adults may delay rehabilitation or result in hospital admission. Prevention, monitoring, and management are critical to preventing dehydration-associated problems.

Understanding clinical dehydration and its treatment

Dehydration in clinical practice, as opposed to a physiological definition, refers to the loss of body water, with or without salt, at a rate greater than the body can replace it. We argue that the clinical definition for dehydration, ie, loss of total body water, addresses the medical needs of the patient most effectively. There are 2 types of dehydration, namely water loss dehydration (hyperosmolar, due either to increased sodium or glucose) and salt and water loss dehydration (hyponatremia). The diagnosis requires an appraisal of the patient and laboratory testing, clinical assessment, and knowledge of the patient's history. Long-term care facilities are reluctant to have practitioners make a diagnosis, in part because dehydration is a sentinel event thought to reflect poor care. Facilities should have an interdisciplinary educational focus on the prevention of dehydration in view of the poor outcomes associated with its development. We also argue that dehydration is rarely due to neglect from formal or informal caregivers, but rather results from a combination of physiological and disease processes. With the availability of recombinant hyaluronidase, subcutaneous infusion of fluids (hypodermoclysis) provides a better opportunity to treat mild to moderate dehydration in the nursing home and at home.

Clinical assessment of dehydration in older people admitted to hospital: what are the strongest indicators?

Due to an absence of published primary data, this study explores dehydration prevalence and the change in physiological parameters frequently used to assess dehydration (fluid deficit) in older hospitalized people, as no standard measurement method exists. This observational longitudinal cohort study recruited 43 people aged 60 years or over, voluntarily admitted to a tertiary teaching hospital's Geriatric and Rehabilitation Unit (GARU). Over 40 clinical, hematological and urinary biochemical parameters employed by medical officers during dehydration assessment, identified through literature, interviews and focus group were investigated. Short-term weight changes, intra- and inter-rater repeatability of dehydration assessments were completed to assess validation and precision of the clinician's clinical dehydration assessment. Systolic blood pressure drop on standing, sternal skin turgor, tongue dryness and body mass index (BMI) were associated with hydration status; demonstrated clinically meaningful differences between groups. BMI negatively confounded the association between dehydration and systolic blood pressure drop on standing. Physical, rather than biochemical, parameters more often identified mild dehydration. The findings challenge common expectations of hematological and physiological measurement changes occurring in older people clinically assessed as dehydrated and emphasize the need to adjust for potential confounders during exploration of the associations of clinical parameters with dehydration status.

A typology of oral hydration problems exhibited by frail nursing home residents

Dehydration remains a substantial problem for nursing home residents, often with poor health outcomes. The purpose of this investigation was to establish 6-month prevalence of dehydration events in nursing home residents and to describe common hydration problems of nursing home residents. In this prospective observational study, 35 nursing home residents were followed for 6 months to assess problems with hydration and to evaluate the presence of dehydration. Urine specific gravity and color, bioimpedance measurements, meal intake recordings, and chart abstraction were used to assess hydration status. Field notes and informal staff interviews were used to describe specific hydration problems and clinically relevant interventions. Dehydration events occurred in 31% (11 of 35) of residents during the 6-month period. A typology of hydration problems was developed from the field observations. The typology consists of four groups (i.e., Can Drink, Can't Drink, Won't Drink, End of Life) and six corresponding subgroups. Demographic and hydration characteristics of the subgroups were compared and contrasted. Comparisons revealed the Won't Drink group is most vulnerable to dehydration events because this group has the highest percentage of dehydration events (58%, 4 of 7), the highest average specific gravity, and the lowest consumption of fluids during meals. Nursing interventions for the subgroups are discussed. Targeting nursing interventions to the specific hydration problem exhibited is proposed.

Elevated sacral skin temperature (Ts): a risk factor for pressure ulcer development in hospitalized neurologically impaired Thai patients

Pressure ulcer incidence and sacral skin temperature (T(s)) were measured in hospitalized neurologically impaired Thai patients ( n = 17) positioned supine and then laterally. Pressure ulcer incidence within 2 weeks of admission was 47%. Regardless of reclining position, mean sacral T(s) in subjects who developed a pressure ulcer was higher ( p < .01) than those who did not develop an ulcer. The data suggest that T(s) may increase at least 1.2 degrees C 24-96 hr before sacral pressure ulcer development. Sacral T(s) may be an objective predictor of sacral pressure ulcer development in hospitalized neurologically impaired Thai patients.

A review of the literature on how important water is to the world's elderly population

AIM

This article reviews the literature on how important water is to the world's elderly population.

BACKGROUND

Water is a finite resource, so we must preserve the water that we have. Physiological aspects and what water requirements our bodies maintain sum up this essential nutrient for life. Dehydration is a concern in the elderly.

CONCLUSIONS

Five strategies related to water intake can promote health: (1) assess for symptoms which may indicate dehydration, (2) encourage ingestion of fluids and foods to maintain an optimal fluid level, (3) be alert to physical and clinical conditions affecting hydration in the elderly, (4) consider environmental factors which may affect body fluids, electrolytes and acid-base balance, and (5) encourage methods to increase fluid consumption.

Reducing hydration-linked events in nursing home residents

The authors used a quasi-experimental treatment and control group design with 49 participants from four nursing homes to test the effectiveness of an 8-week hydration intervention in reducing hydration-linked events (HLEs). A Kaplan Meier survival curve with log rank test was calculated to determine incidence and time to occurrence of a HLE. Incidence of and time to a HLE did not differ between the treatment and control groups over an 8-week period (p > .05). However, treatment group participants were found to be more frail, more cognitively impaired and more at risk for acute confusion than the control group participants. Although there were no statistically significant differences between the groups, it is clinically significant that the frailer, more at-risk participants in the treatment group had a lower incidence of HLEs.

Hydration and acute confusion in long-term care residents

Although it is generally appropriate for a healthy adult to consume 2000 to 2500 ml per day, the literature does not address evaluating any standard. The objective here was to develop a weight-based hydration management intervention and evaluate the impact of this on the incidence of acute confusion (AC) using an N = 98. The intervention consisted of a fluid intake goal based on 100 ml per kg for the first 10 kg, 50 ml/kg for the next 10 kg, and 15 ml for the remaining body weight. The treatment group received instruction and assistance on the fluid goal and the control group received routine care. Measurements included serum electrolytes, bioimpedance analysis, urinalysis, Mini-Mental State Exam, and the NEECHAM. There was no difference in the incidence of AC between treatment and controls, but those individuals with > or = 90% compliance demonstrated higher ECF volumes and also lower urine leukocyte counts.