Risk factors for dehydration among elderly nursing home residents

Urine specific gravity to identify and predict hydration need in ALS

Introduction: Multiple factors contribute to increased risk of dehydration in amyotrophic lateral sclerosis (ALS), which contributes to shortened survival independent of nutritional status. The assessment of hydration by doubly labeled water is restricted due to the limited availability of this gold standard technique for clinical use. This prompted us to examine the utility of urine-specific gravity (USG) as a predictor of hydration need in ALS subjects. Material and Methods: Using data from a multicenter study of 80 ALS subjects with 250 visits, we conducted a secondary analysis of the original data set from doubly labeled water experiments. We used a cross-section of the data (one visit per 75 subjects) in the model selection step ("test set"), and a repeated measures analysis in the validation step with data from 63 subjects and 142 follow-up visits. The sensitivity to detect inadequate water turnover rate (a surrogate for water intake) was the goal of the predictive model presented for clinical use. Results and discussion: The final predictive model to estimate water requirement included USG, gender, body mass index, and the ALSFRS gross motor subscale score. We developed a best-fit equation to estimate water intake from USG, determine hydration status, and improve clinical care of real-world ALS subjects.

The Hydration Status of Adult Patients with Oropharyngeal Dysphagia and the Effect of Thickened Fluid Therapy on Fluid Intake and Hydration: Results of Two Parallel Systematic and Scoping Reviews

BACKGROUND

The effect of oropharyngeal dysphagia (OD) and thickened fluid (TF) therapy on hydration status has not been well defined in the literature. We aimed to assess the hydration status in patients with OD and the effect TF therapy has on it.

METHODS

Two literature reviews following PRISMA methodology (each one including a systematic and a scoping review) were performed: (R1) hydration status in adult patients with OD; (R2) effect of TF therapy on fluid intake and dehydration. Narrative and descriptive methods summarized both reviews. Quality assessment was assessed by Joanna Briggs Institute tools and GRADE.

RESULTS

(R1) Five out of twenty-two studies using analytical parameters or bioimpedance showed poorer hydration status among OD and 19-100% prevalence of dehydration; (R2) two high quality studies (total of 724 participants) showed positive effects of TF on hydration status. Among the articles included, nine out of ten studies that evaluated fluid intake reported a reduced TF intake below basal water requirements.

CONCLUSIONS

Dehydration is a highly prevalent complication in OD. There is scientific evidence on the positive effect of TF therapy on the hydration status of patients with OD. However, strict monitoring of fluid volume intake is essential due to the low consumption of TF in these patients.

Chronic Dehydration in Nursing Home Residents

Chronic dehydration mainly occurs due to insufficient fluid intake over a lengthy period of time, and nursing home residents are thought to be at high risk for chronic dehydration. However, few studies have investigated chronic dehydration, and new diagnostic methods are needed. Therefore, in this study, we aimed to identify risk factors for chronic dehydration by measuring serum osmolality in nursing home residents and also to evaluate whether examining the inferior vena cava (IVC) and determining the IVC collapsibility index (IVC-CI) by ultrasound can be helpful in the diagnosis of chronic dehydration. A total of 108 Japanese nursing home residents aged ≥65 years were recruited. IVC measurement was performed using a portable handheld ultrasound device. Fifteen residents (16.9%) were classified as having chronic dehydration (serum osmolality ≥295 mOsm/kg). Multivariate logistic regression analysis showed that chronic dehydration was associated with dementia (odds ratio (OR), 6.290; 95% confidential interval (CI), 1.270–31.154) and higher BMI (OR, 1.471; 95% CI, 1.105–1.958) but not with IVC or IVC-CI. Cognitive function and body weight of residents should be considered when establishing a strategy for preventing chronic dehydration in nursing homes.

Pain Across the Menstrual Cycle: Considerations of Hydration

Chronic pain – pain that persists for more than 3 months – is a global health problem and is associated with tremendous social and economic cost. Yet, current pain treatments are often ineffective, as pain is complex and influenced by numerous factors. Hypohydration was recently shown to increase ratings of pain in men, but studies in this area are limited (n = 3). Moreover, whether hypohydration also affects pain in women has not been examined. In women, changes in the concentrations of reproductive hormones across menstrual phases may affect pain, as well as the regulation of body water. This indicates potential interactions between the menstrual phase and hypohydration on pain, but this hypothesis has yet to be tested. This review examined the literature concerning the effects of the menstrual phase and hypohydration on pain, to explore how these factors may interact to influence pain. Future research investigating the combined effects of hypohydration and menstrual phase on pain is warranted, as the findings could have important implications for the treatment of pain in women, interpretation of previous research and the design of future studies.

Efficacy of Mealtime Interventions for Malnutrition and Oral Intake in Persons With Dementia: A Systematic Review

Malnutrition and weight loss are highly prevalent in persons with Alzheimer's disease and related dementias. Oral intake is an important interventional target for addressing these nutritional consequences. However, the efficacy of interventions remains poorly understood as prior syntheses have failed to examine the impact of intervention approaches on malnutrition and hypothesized mechanisms of action in persons with dementia. This review aimed to determine the efficacy of mealtime interventions to improve oral intake and nutritional outcomes in persons with dementia. Four databases yielded 1712 studies, resulting in 32 studies that met inclusion criteria. Studies included education, environmental modifications, feeding, oral supplementation, and other pharmacologic/ecopsychological interventions. While the majority of studies reported statistically significant improvements in at least 1 nutritional outcome, study design and outcome measures were heterogenous with many lacking adequate statistical power or blinding. Collectively, we found moderate evidence to suggest the efficacy of oral supplementation, and preliminary evidence to suggest that feeding interventions, education, and environmental modifications may confer improvements. Findings clarify the state of existing evidence regarding various interventional strategies for improving malnutrition in persons with dementia. While some approaches are promising, adequately powered and rigorously designed multidimensional intervention trials are needed to inform clinical decision-making in real-world contexts.

What Serum Sodium Concentration Is Suggestive for Underhydration in Geriatric Patients?

Dehydration is a concern among aging populations and can result in hospitalization and other adverse outcomes. There is a need to establish simple measures that can help in detecting low-intake dehydration (underhydration) in geriatric patients. The predictive performance of sodium, urea, glucose, and potassium to discriminate between patients with and without underhydration was evaluated using receiver-operating characteristic (ROC) curve analysis of data collected during the cross-sectional study of patients admitted to the geriatric ward. A total of 358 participants, for whom osmolarity could be calculated with the Khajuria and Krahn equation, were recruited to the study. Impending underhydration (osmolarity > 295 mmol/L) was diagnosed in 58.4% of cases. Serum sodium, urea, fasting glucose, and potassium (individual components of the equation) were significantly higher in dehydrated participants. The largest ROC area of 0.88 was obtained for sodium, and the value 140 mMol/L was found as the best cut-off value, with the highest sensitivity (0.80; 95% CI: 0.74–0.86) and specificity (0.83; 95% CI: 0.75–0.88) for prediction of underhydration. The ROC areas of urea, glucose, and potassium were significantly lower. Serum sodium equal to 140 mmol/L or higher appeared to be suggestive of impending underhydration in geriatric patients. This could be considered as the first-step screening procedure for detecting underhydration in older adults in general practice, especially when limited resources restrict the possibility of more in-depth biochemical assessments.

Impending Low Intake Dehydration at Admission to A Geriatric Ward- Prevalence and Correlates in a Cross-Sectional Study

Dehydration risk increases with frailty and functional dependency, but a limited number of studies have evaluated this association in hospitalized geriatric patients. This cross-sectional study aimed to assess the prevalence and determinants of dehydration in patients admitted to the geriatric ward. Dehydration was diagnosed when calculated osmolarity was above 295 mMol/L. Logistic regression analyses (direct and stepwise backward) were used to assess determinants of impending dehydration. 358 of 416 hospitalized patients (86.1%) were included: 274 (76.5%) women, and 309 (86.4%) 75+ year-old. Dehydration was diagnosed in 209 (58.4%) cases. Significantly higher odds for impending dehydration were observed only for chronic kidney disease with trends for diabetes and procognitive medication when controlling for several health, biochemical, and nutritional parameters and medications. After adjusting for “dementia” the negative effect of “taking procognitive medications” became a significant one. Chronic kidney disease, diabetes, taking procognitive medications and hypertension were the main variables for the outcome prediction according to the stepwise backward regression analysis. This may indicate an additional benefit of reducing the risk of dehydration when using procognitive drugs in older patients with dementia.

Management of Dehydration in Patients Suffering Swallowing Difficulties

Swallowing difficulties, also called dysphagia, can have various causes and may occur at many points in the swallowing process. The treatment and rehabilitation of dysphagia represent a major interdisciplinary and multiprofessional challenge. In dysphagic patients, dehydration is frequent and often accelerated as a result of limited fluid intake. This condition results from loss of water from the intracellular space, disturbing the normal levels of electrolytes and fluid interfering with metabolic processes and body functions. Dehydration is associated with increased morbidity and mortality rates. Dysphagic patients at risk of dehydration thus require close monitoring of their hydration state, and existing imbalances should be addressed quickly. This review gives an overview on dehydration, as well as its pathophysiology, risk factors, and clinical signs/symptoms in general. Available management strategies of dehydration are presented for oral, enteral, and parenteral fluid replacement.

Dehydration assessment via a portable, single sided magnetic resonance sensor

PURPOSE

Undiagnosed dehydration compromises health outcomes across many populations. Existing dehydration diagnostics require invasive bodily fluid sampling or are easily confounded by fluid and electrolyte intake, environment, and physical activity limiting widespread adoption. We present a portable MR sensor designed to measure intramuscular fluid shifts to identify volume depletion.

METHODS

Fluid loss is induced via a mouse model of thermal dehydration (37°C; 15-20% relative humidity). We demonstrate quantification of fluid loss induced by hyperosmotic dehydration with multicomponent T2 relaxometry using both a benchtop NMR system and MRI localized to skeletal muscle tissue. We then describe a miniaturized (~1000 cm³ ) portable (~4 kg) MR sensor (0.28 T) designed to identify dehydration-induced fluid loss. T2 relaxometry measurements were performed using a Carr-Purcell-Meiboom-Gill pulse sequence in ~4 min.

RESULTS

T2 values from the portable MR sensor exhibited strong (R² = 0.996) agreement with benchtop NMR spectrometer. Thermal dehydration induced weight loss of 4 to 11% over 5 to 10 h. Fluid loss induced by thermal dehydration was accurately identified via whole-animal NMR and skeletal muscle. The portable MR sensor accurately identified dehydration via multicomponent T2 relaxometry.

CONCLUSION

Performing multicomponent T2 relaxometry localized to the skeletal muscle with a miniaturized MR sensor provides a noninvasive, physiologically relevant measure of dehydration induced fluid loss in a mouse model. This approach offers sensor portability, reduced system complexity, fully automated operation, and low cost compared with MRI. This approach may serve as a versatile and portable point of care technique for dehydration monitoring.

Where there is sodium there may be sepsis

Hypernatremia affects up to 9% of critically ill patients upon hospital admission, especially in elderly patients with thirst impairment. However, hypernatremia is not entirely explained by fluid imbalance. Recent studies suggest that sodium is an important enhancer of the immune system, raising the question of whether inflammatory states such as sepsis may contribute to hypernatremia. Although sepsis patients with hypernatremia face a greater mortality rate, there is a lack of studies examining a potential association between hypernatremia and sepsis. Motivated by the frequent concurrence of hypernatremia and sepsis observed at an eastern Pennsylvanian community hospital, the current study was conducted to evaluate whether hypernatremia on admission may serve as a potential surrogate marker for sepsis. The medical records of 153 patients with hypernatremia on admission (serum sodium > 145mEq/L) were retrospectively analyzed. The mean age of patients was 81.1. Sepsis was observed in 77.1% of patients, of which 86.2% had dementia. This study demonstrated a positive correlation between hypernatremia on admission and the presence of sepsis. We suggest that the existence of hypernatremia should prompt clinicians to further investigate for sources of infection, especially in the elderly and patients with dementia.

Sudden unexpected death in Parkinson’s disease: why is drinking water important?

Parkinson’s disease (PD) is one of the most common age-related neurodegenerative disorders. Several studies over the last few years have shown that PD is accompanied by high rates of premature death compared with healthy controls. Death in PD patients is usually caused by determinant factors such as pneumonia, and cerebrovascular and cardiovascular diseases. During recent years it has emerged that dehydration may also contribute to mortality in PD. Interestingly, it has been documented that a substantial proportion of patients with PD die suddenly (known as sudden and unexpected death in PD). In this article, we focus on the magnitude of the problem of sudden and unexpected death in PD, with special reference to the daily water consumption of PD patients.

A multidisciplinary consensus on dehydration: definitions, diagnostic methods and clinical implications

Background: Dehydration appears prevalent, costly and associated with adverse outcomes. We sought to generate consensus on such key issues and elucidate need for further scientific enquiry. Materials and methods: A modified Delphi process combined expert opinion and evidence appraisal. Twelve relevant experts addressed dehydration's definition, objective markers and impact on physiology and outcome. Results: Fifteen consensus statements and seven research recommendations were generated. Key findings, evidenced in detail, were that there is no universally accepted definition for dehydration; hydration assessment is complex and requires combining physiological and laboratory variables; "dehydration" and "hypovolaemia" are incorrectly used interchangeably; abnormal hydration status includes relative and/or absolute abnormalities in body water and serum/plasma osmolality (pOsm); raised pOsm usually indicates dehydration; direct measurement of pOsm is the gold standard for determining dehydration; pOsm >300 and ≤280 mOsm/kg classifies a person as hyper or hypo-osmolar; outside extremes, signs of adult dehydration are subtle and unreliable; dehydration is common in hospitals and care homes and associated with poorer outcomes. Discussion: Dehydration poses risk to public health. Dehydration is under-recognized and poorly managed in hospital and community-based care. Further research is required to improve assessment and management of dehydration and the authors have made recommendations to focus academic endeavours. Key messages Dehydration assessment is a major clinical challenge due to a complex, varying pathophysiology, non-specific clinical presentations and the lack of international consensus on definition and diagnosis. Plasma osmolality represents a valuable, objective surrogate marker of hypertonic dehydration which is underutilized in clinical practice. Dehydration is prevalent within the healthcare setting and in the community, and appears associated with increased morbidity and mortality.

Hydration Status of Assisted Living Memory Care Residents

Water intake and hydration status of assisted living memory care (ALMC) residents were evaluated. Thirty-two residents (eight men; mean age 86.5 years; Global Deterioration Scale [GDS] 3 to 7) from four ALMC units participated. Ingested food and fluid amount, type, and time, and ingestion behaviors were observed from 7:00 a.m. to 7:00 p.m. Related factors were obtained from chart review/participant survey. Mean fluid intake was 1,160.16 mL; mean water intake from food and fluid was 56.55% (SD = 23.4%) of recommended water intake (RWI). Only one participant met 100% RWI. Using osmolality laboratory results (available for 21 participants), five participants were hydrated, whereas eight (38.1%) participants were in impending dehydration and dehydration categories, respectively. Fluid intake, GDS, and level of assistance during meals predicted RWI. Water intake of ALMC residents is inadequate, placing them at risk for dehydration, and justifies development and implementation of care standards for increasing water intake. [Journal of Gerontological Nursing, 45(4), 21-29.].

Frequency, Risk Factors, and Prognosis of Dehydration in Acute Stroke

Objective: To determine the frequency, risk factors, and impact on the outcome of dehydration after stroke. Methods: In this cross-sectional observational study, we included prospectively and consecutively patients with ischemic and hemorrhagic stroke. The serum Urea/Creatinine ratio (U/C) was calculated at admission and 3 days after the stroke. Dehydration was defined as U/C>80. Patients were treated in accordance with the standard local hydration protocol. Demographic and clinical data were collected. Neurological severity was evaluated at admission according to the NIHSS score; functional outcome was assessed with the modified Rankin scale score (mRS) at discharge and 3 months after the stroke. Unfavorable outcome was defined as mRS > 2. Results: We evaluated 203 patients; 78.8% presented an ischemic stroke and 21.2% a hemorrhagic stroke. The mean age was 73.4 years ±12.9; 51.7% were men. Dehydration was detected in 18 patients (8.9%), nine patients at admission (4.5%), and nine patients (4.5%) at 3 days after the stroke. Female sex (OR 3.62, 95%CI 1.13-11.58, p = 0.03) and older age (OR 1.05, 95%CI 1-1.11, p = 0.048) were associated with a higher risk of dehydration. Dehydration was significantly associated with an unfavorable outcome at discharge (OR 5.16, 95%CI 1.45-18.25, p = 0.011), but the association was not significant at 3 months (OR 2.95, 95%CI 0.83-10.48, p = 0.095). Conclusion: Dehydration is a treatable risk factor of a poor functional outcome after stroke that is present in 9% of patients. Females and elders present a higher risk of dehydration.

Risk factors associated with dehydration in older people living in nursing homes: Scoping review

BACKGROUND

Dehydration in the older people is a prevalent problem that is often associated with physiological changes, physical limitations and environmental conditions.

OBJECTIVES

The scoping review was carried out to identify risk factors associated with dehydration in older people living in nursing homes.

DESIGN

The revised scoping methodology framework of Arksey and O'Malley (2005) was applied. Study selection was carried out in accordance with Davis et al. (2009) and focused on the inclusion criteria (people over 65 years old and living in nursing homes). Risk factors were classified using the geriatric assessment.

DATA SOURCES

An electronic database search was performed in PubMed, Scopus and CINAHL. The literature search was carried out between October 2016 and January 2017.

REVIEW METHODS

Thematic reporting was performed and study findings were validated through interdisciplinary meetings of experts. The quality of the papers consulted was also evaluated using the Newcastle-Ottawa Scale adapted for cross-sectional, cohort and case-control studies.

RESULTS

In all, 16 papers were analysed, all of which were observational studies. The risk of bias ranged from very low (n = 1), to medium (n = 13) and high (n = 2). The risk factors were classified in line with the different components of the geriatric assessment. In the socio-demographic characteristics age and gender were identified. In the clinical component, infections, renal and cardiovascular diseases and end-of-life situations were the most common factors highlighted in the papers analysed. With reference to the functional component, its limitation was associated with dehydration, while for factors of mental origin, it was related to dementia and behavioural disorders. Finally, the factors relating to the social component were institutionalisation, requiring a skilled level of care and it being winter.

CONCLUSIONS

The most commonly repeated factors highlighted in the review were age, gender, infections, end of life and dementia, with it being important to highlight the large number of factors in the clinical component. Even so, the great majority of the factors were unmodifiable conditions associated typically associated with the physiology of ageing.

Hydration measured by doubly labeled water in ALS and its effects on survival

We present a study of hydration in ALS patients and its effects on survival. This was a multicenter study over 48 weeks in 80 ALS patients who underwent 250 individual measurements using doubly labeled water (DLW). Total body water (TBW) and water turnover (a surrogate for water intake) were 3.4% and 8.6% lower, respectively, in patients compared to age- and gender-matched healthy controls, and both significantly decreased over study duration. In 20% of patients, water turnover measured over 10 d was 2 standard deviations below the mean value in healthy controls. In a separate clinic cohort of 208 patients, water intake estimated from a de novo equation created from common clinical endpoints was a prognostic indicator of survival. Regardless of nutritional state assessed by BMI, survival was two-fold longer in the group above the median for estimated water intake, suggesting that hydration may be a more important predictor of survival than malnutrition. Risk factors for poor hydration were identified. Water intake equations recommended by US Centers for Medicare and Medicaid Services in healthy elderly were inaccurate for use in ALS patients. We developed equations to estimate TBW and water intake in ALS patients for use in clinics to accurately estimate hydration and improve clinical care.

Phyllanthus niruri leaves aqueous extract improves kidney functions, ameliorates kidney oxidative stress, inflammation, fibrosis and apoptosis and enhances kidney cell proliferation in adult male rats with diabetes mellitus

ETHNOPHARMACOLOGICAL RELEVANCE

Phylanthus niruri has been used to treat ailments related to the urogenital organs. In this study, this herb was hypothesized to help to ameliorate kidney disease in diabetes mellitus (DM).

AIMS

To investigate P. niruri leaves aqueous extract (PN) effects on kidney functions, histopathological changes and levels of oxidative stress, inflammation, fibrosis, apoptosis and proliferation in DM.

METHODS

PN was orally administered to streptozotocin-nicotinamide-induced male diabetic rats for 28 days. At the end of the treatment, fasting blood glucose (FBG) and kidney functions were measured. Kidney somatic index, histopathological changes and levels of RAGE, Nrf2, oxidative stress markers (TBARS, SOD, CAT and GPx), inflammatory markers (NFkβ-p65, Ikk-β, TNF-α, IL-1β and IL-6), apoptosis markers (caspase-3, caspase-9 and Bax), fibrosis markers (TGF-β1, VEGF and FGF-1) and proliferative markers (PCNA and Ki-67) were determined by biochemical assays, qPCR, Western blotting, immunohistochemistry or immunofluorescence.

RESULTS

Administration of PN helps to maintain near normal FBG, creatinine clearance (CCr), blood urea nitrogen (BUN), BUN/Cr ratio, serum electrolytes, uric acid and urine protein levels in DM. Decreased RAGE, TBARS and increased Nrf2, SOD-1, CAT and GPx-1 were observed in PN-treated diabetic rat kidneys. Expression of inflammatory, fibrosis and apoptosis markers in the kidney reduced but expression of proliferative markers increased following PN treatment. Lesser histopathological changes were observed in the kidney of PN-treated diabetic rats.

CONCLUSION

PN helps to preserve near normal kidney function and prevents histopathological changes via ameliorating oxidative stress, inflammation, fibrosis and apoptosis while enhancing proliferation of the kidney in DM.

Clinical aspects of changes in water and sodium homeostasis in the elderly

The population of elderly individuals is increasing worldwide. With aging, various hormonal and kidney changes occur, both affecting water homeostasis. Aging is a risk factor for chronic kidney disease (CKD) and many features of CKD are reproduced in the aging kidney. Dehydration and hyperosmolarity can be triggered by diminished thirst perception in this population. Elderly with dementia are especially susceptible to abnormalities of their electrolyte and body water homeostasis and should be (re-)assessed for polypharmacy. Hypo- and hypernatremia can be life threatening and should be diagnosed and treated promptly, following current practice guidelines. In severe cases of acute symptomatic hyponatremia, a rapid bolus of 100 to 150 ml of intravenous 3% hypertonic saline is appropriate to avert catastrophic outcomes; for asymptomatic hyponatremia, a very gradual correction is preferred. In summary, the body sodium (Na+) balance is regulated by a complex interplay of environmental and individual factors. In this review, we attempt to provide an overview on this topic, including dehydration, hyponatremia, hypernatremia, age-related kidney changes, water and sodium balance, and age-related changes in the vasopressin and renin-angiotensin-aldosterone system.

Association between Dietary Sodium Intake and Cognitive Function in Older Adults

OBJECTIVE

To examine the association of dietary sodium intake with cognitive function in community-dwelling older adults.

DESIGN

Cross-sectional study.

SETTING

Southern California community.

PARTICIPANTS

White men (n=373) and women (n=552), aged 50-96 years from the Rancho Bernardo Study, a longitudinal study of cardiovascular disease risk factors and healthy aging.

MEASUREMENTS

During the 1992-1996 research clinic visit, a food frequency questionnaire was used to determine daily sodium intake; cognitive function was assessed with Trails Making Test, part B (Trails B), Mini-Mental State Exam (MMSE), and Verbal Fluency Test (VFT); and medical, clinical and demographic information was obtained. Linear regression was used to assess the association between calorie-adjusted sodium intake and cognitive test scores with adjustment for demographic, behavioral and health measures. Logistic regression examined the odds of having cognitive impairment by sodium intake.

RESULTS

Lower sodium intake was associated with poorer performance on Trails B (p=0.008) and MMSE (p=0.003) after controlling for age, sex, and education. Associations did not differ by sex, but there was a significant interaction by age for the Trails B: older (≥80 years), but not younger, adults showed worse performance with lower sodium intake (p=0.03). Associations remained significant after additional adjustment for smoking, alcohol intake, exercise, body weight, cardiovascular risk factors, kidney function, diuretic medication use, and diet quality. Lower daily sodium intake was associated with increased odds of cognitive impairment on the MMSE (score < 26; OR per SD decrease = 1.12, 95% CI 1.08, 1.16). Concluson: Lower sodium intake was associated with worse cognitive function in older community-dwelling adults. For the maintenance of cognitive health, older adults may be advised to avoid very low sodium diets.

Acoustical Method of Whole-Body Hydration Status Monitoring

An acoustical handheld hydration monitor (HM) for assessing the water balance of the human body was developed. Dehydration is a critical public health problem. Many elderly over age of 65 are particularly vulnerable as are infants and young children. Given that dehydration is both preventable and reversible, the need for an easy-to-perform method for the detection of water imbalance is of the utmost clinical importance. The HM is based on an experimental fact that ultrasound velocity in muscle is a linear function of water content and can be referenced to the hydration status of the body. Studies on the validity of HM for the assessment of whole-body hydration status were conducted in the Appalachian State University, USA, on healthy young adults and on elderly subjects residing at an assisted living facility. The HM was able to track changes in total body water during periods of acute dehydration and rehydration in athletes and day-to-day and diurnal variability of hydration in elderly. Results of human studies indicate that HM has a potential to become an efficient tool for detecting abnormal changes in the body hydration status.

Validation analysis of a geriatric dehydration screening tool in community-dwelling and institutionalized elderly people

Dehydration is common among elderly people. The aim of this study was to perform validation analysis of a geriatric dehydration-screening tool (DST) in the assessment of hydration status in elderly people. This tool was based on the DST proposed by Vivanti et al., which is composed by 11 items (four physical signs of dehydration and seven questions about thirst sensation, pain and mobility), with four questions extra about drinking habits. The resulting questionnaire was evaluated in a convenience sample comprising institutionalized (n = 29) and community-dwelling (n = 74) elderly people. Urinary parameters were assessed (24-h urine osmolality and volume) and free water reserve (FWR) was calculated. Exploratory factor analysis was used to evaluate the scale’s dimensionality and Cronbach’s alpha was used to measure the reliability of each subscale. Construct’s validity was tested using linear regression to estimate the association between scores in each dimension and urinary parameters. Two factors emerged from factor analysis, which were named “Hydration Score” and “Pain Score”, and both subscales showed acceptable reliabilities. The “Hydration Score” was negatively associated with 24-h urine osmolality in community-dwelling; and the “Pain Score” was negatively associated with 24-h urine osmolality, and positively associated with 24-h urine volume and FWR in institutionalized elderly people.

Intake of thickened liquids by hospitalized adults with dysphagia after stroke

There is widespread concern that individuals with dysphagia as a result of stroke do not drink enough fluids when they are prescribed thickened liquids. This paper details a retrospective audit of thickened liquid consumption of 69 individuals with dysphagia following stroke in acute and rehabilitation hospitals in Adelaide, South Australia. Hospitalized individuals with dysphagia following stroke drank a mean of 781 ml (SD = 507 ml) of prescribed thickened liquids per day, significantly less in the acute setting (M = 519 ml, SD = 305 ml) than in the rehabilitation setting (M = 1274 ml, SD = 442 ml) (t(67) = -8.34, p < .001). This daily intake of thickened liquids was lower than recommended standards of fluid intake for hospitalized adults. Fluid intake could be increased with definitive protocols for the provision and monitoring of consumption of thickened liquids, by offering more fluid via food or free water protocols or by routine use of non-oral supplementary routes. Future research into the effectiveness of such recommendations needs to evaluate not only the impact on fluid intake but also on health outcomes.

Acute kidney injury, sodium disorders, and hypercalcemia in the aging kidney: diagnostic and therapeutic management strategies in emergency medicine

This article summarizes the current literature regarding the structural and functional changes of the aging kidney and describes how these changes make the older patient more susceptible to acute kidney injury and fluid and electrolyte disorders. It discusses the clinical manifestations, evaluation, and management of hyponatremia and shows how the management of hypernatremia in geriatric patients involves addressing the underlying cause and safely correcting the hypernatremia. The current literature regarding evaluation and management of hypercalcemia in older patients is summarized. The management of severe hypercalcemia is discussed in detail. The evaluation and management of acute kidney injury is described.

Reduced hydration status characterized by disproportionate elevation of blood urea nitrogen to serum creatinine among the patients with cerebral infarction

The significance of fluid metabolism among the patients with cerebral infarction has barely mentioned in the literature despite the several reports suggesting the potential risk of reduced hydration status for the development of cerebral infarction. The aim of the this study is to explore the validity of the presumable relationship between hydration status and cerebral infarction. Ninety-seven patients with cerebral infarction from April 1, 2008 to March 31, 2009 were retrospectively investigated, and their hydration status were evaluated by using several clinical parameters such as a blood urea nitrogen to serum creatinine (BUN/Cr) ratio of >25 and plasma osmolality. Subjects with active infection, congestive heart failure, hepatic failure, gastrointestinal bleeding, or a malignancy were excluded since these conditions should modulate the absolute value of BUN/Cr ratio without a change in hydration status. Twenty-eight patients (29%) were considered as having reduced hydration status. The BUN/Cr ratio decreased significantly after the initiation of medical support (median 21.3; IR: 18.1-24.6), including oral or parenteral fluid supplementation, in comparison to the values at the time of patient admission (median 30.0; IR: 26.8-40.7; p<0.0001). Similar decreases were also observed in the hematocrit, hemoglobin, and plasma osmolality. The group considered to have reduced hydration status had a significantly higher prevalence of cardioembolic stroke than the other subjects. The hydration status may be a contributing factor to subtypes of cerebral infarction. Whether our findings are also the case with overall patients with cerebral infarction should be evaluated in greater detail.

[Risk factors contributing to insufficient water intake in elderly living in nursing homes and long-term care units: a review of the literature]

Elderly living in nursing homes and long-term care units are well-known to be vulnerable to dehydration. Insufficient water intake contributes to suboptimal hydration status and leads to decreased quality of life and global health status. Based on published studies, 32 to 96% of nursing home residents had insufficient water intake and more than 50% drank less than 1.5L per day. Risk factors contributing to decreased water intake in nursing home residents can be divided into two categories, depending whether they apply to the individuals per se (individual factors) or their social and institutional environment (environmental factors). Water intake is associated with meals and medication administration frequency. Diminished thirst sensation, intentional fluid restriction, dysphagia and functional dependency are individual factors recognized as most contributing to decreased water intake. Lack of familial support and insufficient staff are also important since they can contribute to decreased patients' assistance. Dietitians can play a fundamental role in preventing suboptimal hydration status by identifying risk factors that are known to compromise individual's water intake and by implementing corrective measures.

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.

Geriatric nephrology: responding to a growing challenge

Changing demographics of the global population predict that the number of people age 65 years or greater will triple over the coming decades. Because the incidence and prevalence of kidney disease increase with advancing age, nephrologists will be increasingly confronted with a population of patients who are elderly and have a large number of comorbid conditions requiring ongoing care. Furthermore, it is increasingly understood that aging leads to its own unique aspects of nephrologic diagnosis and treatment. Although it is known that elderly patients constitute a group with special needs and present unique challenges to the nephrologist, traditional nephrology fellowship training has not included a focus on the geriatric population. In response to this need for greater education and awareness, the American Society of Nephrology has initiated a program of educational activities in geriatric nephrology and has chartered a specific advisory council. The priority being given to geriatric nephrology is a hopeful sign that issues such as treatment options, the efficacy of treatments, and their effect on quality of life for the elderly patient with kidney disease will be improved in the coming years.

Acute kidney injury in the elderly: pathogenesis, diagnosis and therapy

Elderly patients, especially those with chronic kidney disease, are at least a 3.5-fold higher risk for the development of acute kidney injury (AKI). With aging, renal functional reserve is lower owing to specific cellular changes that affect function. Molecular studies are elucidating these cellular changes and offer the prospect of designing novel therapeutics. The spectrum of AKI in elderly patients is wide but is over-represented by prerenal and postrenal (obstructive) etiologies. This reflects potentially nephrotoxic clinical variables, such as combordid states, impaired baseline renal function, polypharmacy and an increase in high-risk procedures. In this population, the development of AKI can lead to longer hospital stays, higher mortality rates and an increased risk for the development of chronic kidney disease and end-stage renal disease. Careful attention to clinical risk factors, avoidance of nephrotoxic insults and meticulous supportive care for patients who develop AKI is critical in alleviating the burden of this problem.

Preventing and treating dehydration in the elderly during periods of illness and warm weather

OBJECTIVE

Translate the available knowledge on ageing and dehydration into main messages for clinical practice.

MAIN POINTS

Older people are more susceptible to dehydration than younger people. This is partly due to lack of thirst sensation and changes in the water and sodium balance that naturally occur as people age. It is also, to some degree, attributable to the fact that elderly people, both those living at home and those living in institutions, often have various impairments, disabilities and/or handicaps (comorbidity). They also tend to use numerous drugs and medication for these illnesses (polypharmacy). Multimorbidity and polypharmacy often overstress the normal age-related physiological changes in the water and sodium balance and therefore increase elderly people's risk of dehydration,especially during intercurrent infections or warm weather. Elderly people, whether they are living on their own or in an institution, and especially elderly people that can no longer take care of themselves because of cognitive, sensory, motor and/or ADL impairments, need extra help to stay hydrated. The most important strategy is simply a matter of ensuring that elderly people consume a sufficient amount of fluids (at least 1.7 liters every 24 hours). Additional strategies include making healthy drinks and water easily available and accessible at all times and reminding and encouraging the elderly to consume these fluids. Elderly people should not be encouraged to consume large amounts of fluids at once but rather small amounts throughout the day. When the recommended fluid intake cannot, for whatever reason, be realized, fluids can be administered via catheter or by hypodermoclysis. In more specific and severe cases, fluids can be administered intravenously.

CONCLUSION

The prevention, signaling and treatment of dehydration in the elderly is an important multidisciplinary endeavor. Formal and informal care providers need to continuously be aware of the risk factors and signs of dehydration in the elderly, especially during periods of very warm weather and when older people are ill. Standard professional care for high risk patients is imperative.

Serum markers of chronic dehydration are associated with saliva spinability

Findings of a relationship between saliva and dehydration have been observed, but the precise nature of these relationships is unclear and no evidence of a direct link has been found. In particular, no study reports a relationship between chronic dehydration and saliva conditions in community-dwelling older adults. This study aimed to identify whether salivary conditions are sensitive to body hydration markers in an elderly population. A total of 403 subjects aged 76 years participated in the study. Stimulated saliva flow rate and spinability of saliva were measured. In addition, determinations of serum levels of uric acid, blood urea nitrogen (BUN), creatinine, sodium and potassium were made. Dehydration was defined as uric acid >/= 7 mg dL(-1) according to the standard value. The salivary spinability were significantly associated with the concentration of uric acid (OR=2.06, P=0.044) according to multiple logistic regression analysis. In addition, after adjusting for gender, the uric acid concentration and the salivary spinability was significantly associated with BUN, potassium and creatinine levels. The subjects with high uric acid levels (>/= 7 mg dL(-1)) had the most elastic saliva. Both BUN and serum creatinine are the most commonly used indicators of renal function. Therefore, our findings might demonstrate that older adults who are dehydrated showed highly elastic saliva, which was associated with renal function. In conclusion, this study suggests that there is a significant relationship between chronic dehydration status and salivary spinability level.

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.

Dehydration among Long-Term Care Elderly Patients with Oropharyngeal Dysphagia

INTRODUCTION

Long-term care (LTC) residents, especially the orally fed with dysphagia, are prone to dehydration. The clinical consequences of dehydration are critical. The validity of the common laboratory parameters of hydration status is far from being absolute, especially so in the elderly. However, combinations of these indices are more reliable.

OBJECTIVE

Assessment of hydration status among elderly LTC residents with oropharyngeal dysphagia.

METHODS

A total of 28 orally fed patients with grade-2 feeding difficulties on the functional outcome swallowing scale (FOSS) and 67 naso-gastric tube (NGT)-fed LTC residents entered the study. The common laboratory, serum and urinary tests were used as indices of hydration status. The results were considered as indicative of dehydration and used as 'markers of dehydration', if they were above the accepted normal values.

RESULTS

The mean number of dehydration markers was significantly higher in the FOSS-2 group (3.8 +/- 1.3 vs. 2 +/- 1.4, p = 0.000). About 75% of these FOSS-2 patients had > or =4 dehydration markers versus 18% of the NGT-fed group (p = 0.000). A low urine output (<800 ml/day) was significantly more common in the FOSS-2 group (39 vs. 12%, p = 0.002). Above normal values of blood urea nitrogen (BUN), BUN/serum creatinine ratio (BUN/S(Cr)), urine/serum osmolality ratio (U/S(Osm)), and urine osmolality U(Osm), were significantly more frequent in the dehydration-prone FOSS-2 group. This combination of 4 indices was present in 65% of low urine output patients. In contrast, it was present in only 36% of the higher urine output patients (p = 0.01). Patients with a 'normal' daily urine output (>800 ml/day) also had a significant number (2 +/- 1.5) of positive indices of dehydration.

CONCLUSIONS

Dehydration was found to be common among orally fed FOSS-2 LTC patients. Surprisingly, probable dehydration, although of a mild degree, was not a rarity among NGT-fed patients either. The combination of 4 parameters, BUN, BUN/S(Cr ), U/S(Osm) and U(Osm), offers reasonable reliability to be used as an indication of dehydration status in daily clinical practice.

Is the prevalence of dehydration among community-dwelling older adults really low? Informing current debate over the fluid recommendation for adults aged 70+years

Objective

The fluid recommendation for adults aged 70+ years has been criticised on the basis of a low prevalence of dehydration in community-dwelling older adults. This study explores whether the low prevalence might reflect limitations of individual dehydration indices.

Design

Cross-sectional data on plasma sodium, blood urea nitrogen (BUN), creatinine, glucose and potassium were used to classify 1737 participants of the 1992 Established Populations for Epidemiologic Studies of the Elderly (EPESE) (70+ years) according to multiple dehydration indices. Associations between dehydration indices, health and functional status were evaluated.

Results

Depending on the indicator used, the prevalence of dehydration ranged from 0.5% for hypotonic hypovolaemia only (plasma tonicity <285 mOsm l−1 with orthostatic hypotension) to 60% with dehydration defined as either plasma sodium ≥145 mEq l−1, BUN/creatinine ratio ≥20, tonicity ≥295 mOsm l−1, or hypotonic hypovolaemia. Elevated tonicity and BUN/creatinine ratio were respectively associated with chronic disease and functional impairment.

Conclusions

The true prevalence of dehydration among community-dwelling adults may be low or high, depending on the indicator(s) used to define dehydration. Before we can pinpoint a generalisable prevalence of dehydration for community-dwelling seniors and draw conclusions about fluid recommendations, validation studies of dehydration indices and longitudinal studies of dehydration, health and functional status are needed.

Clinical Presentation of Hypernatremia in Elderly Patients: A Case Control Study

OBJECTIVES

To assess early clinical signs and their prognostic value in elderly patients with hypernatremia.

DESIGN

Prospective, case control study of 150 patients with hypernatremia matched to 300 controls.

SETTING

Multicenter study including seven short- and long-term geriatric care facilities.

MEASUREMENTS

Clinical assessment of hydration status at bedside, such as abnormal skin turgor or dry oral mucosa.

SECONDARY OUTCOME MEASURES

30-day mortality rate and clinical indicators (assessed at the peak of natremia) associated with mortality.

RESULTS

Patients and controls were comparable in terms of drugs and underlying diseases, except for history of dementia, which was more frequent in patients than in controls. Patients were significantly more likely than controls to have low blood pressure, tachycardia, dry oral mucosa, abnormal skin turgor, and recent change of consciousness. Only three clinical findings were found in at least 60% of patients with hypernatremia: orthostatic blood pressure and abnormal subclavicular and forearm skin turgor. The latter two signs were significantly more frequent in patients with hypernatremia. Four other signs (tachycardia, abnormal subclavicular skin turgor, dry oral mucosa, and recent change of consciousness) had a specificity of greater than 79%. Using logistic regression, four signs were significantly and independently associated with hypernatremia: abnormal subclavicular and thigh skin turgor, dry oral mucosa, and recent change of consciousness. The mortality rate was 41.5% and was significantly higher in patients with hypernatremia. The status of consciousness when hypernatremia was diagnosed was the single prognostic indicator associated with mortality (odds ratio=2.3, 95% confidence interval=1.01-5.2).

CONCLUSION

Most of the classical signs of dehydration are irregularly present in patients with hypernatremia. Caregivers should carefully screen any variations in consciousness, because they may reveal severe hypernatremia.