Indices of dehydration among frail nursing home patients: highly variable but stable over time

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.

A pilot clinical evaluation of oral mucosal dryness in dehydrated patients using a moisture-checking device

This study included 30 patients (17 males and 13 females; mean age, 73.7 ± 13.1 years) who were diagnosed with dehydration based on vital signs, skin symptoms, and blood test findings by emergency medicine physicians. First, the attending physician of our department measured oral mucosal dryness. Subsequently, the emergency medicine physician blindly divided the severity of dehydration into three stages according to clinical findings and blood test results. In this study, the oral moisture-checking device (Mucus®; Life Co., Ltd., Saitama, Japan) was used to measure the oral mucosal dryness. We examined the oral moisture level for each dehydration severity level and the correlations of each severity level of dehydration with the measured values. Spearman's correlation coefficient (Medcalc version 11.3 for Windows) was used for statistical analysis. P < 0.05 indicated significant differences. Twenty-six patients were diagnosed with dry mouth, and a moderate negative correlation was found between the severity of dehydration and oral moisture degree (r = -0.686). The correlation coefficient for the relationship between oral moisture degree and severity of dehydration was -0.686, indicating a negative correlation (P < .05). These results suggest that the oral mucosal dryness may be a useful index of dehydration severity.

Evaluation of water balance in a population of older adults. A case control study

Older adults are at risk for dehydration and its' potentially life-threatening consequences. Unrecognized dehydration can complicate chronic medical problems and increase morbidity. The objective of the study was to estimate water balance, intake and loss in elderly people living in Greece using the Water Balance Questionnaire (WBQ). WBQ was administered in winter to 108 independents (65-81yrs) (Group A), 94 independents (82-92yrs) (Group B) and 51 hospitalized (65-92yrs) (Group C). A database from previous study of 335 adults (18-65yrs) (Control Group) used for comparison. Mean estimates of water balance, intake and loss were, respectively, for Group A -749 ± 1386 mL/day, 2571 ± 739 mL/day and 3320 ± 1216 mL/day, for Group B -38 ± 933 mL/day, 2571 ± 739 mL/day and 3320 ± 1216 mL/day, for Group C 64 ± 1399 mL/day, 2586 ± 1071 mL/day and 2522 ± 1048 mL/day and for Control Group -253 ± 1495 mL/day, 2912 ± 1025 mL/day and 3492 ± 2099 mL/day. Significant differences were detected in water balance, intake and loss (p < 0.01). Water balance and water intake in Group A was the lowest. For Groups A, B, C and Control, contribution of solid foods to water intake was 36%, 29%, 32%, 25%, of drinking water was 32%, 48%, 45%, 47%, of beverages was 32%, 23%, 23% and 28% respectively. Significant differences observed in the contribution of drinking water and beverages (p < 0.01). Group A had lower water balance and water intake. Groups B and C had lower water intake from beverages.

Dehydration in the Elderly: A Review Focused on Economic Burden

BACKGROUND

Dehydration is the most common fluid and electrolyte problem among elderly patients. It is reported to be widely prevalent and costly to individuals and to the health care system. The purpose of this review is to summarize the literature on the economic burden of dehydration in the elderly.

METHOD

A comprehensive search of several databases from database inception to November 2013, only in English language, was conducted. The databases included Pubmed and ISI Web of Science. The search terms «dehydration» / "hyponaremia" / "hypernatremia" AND «cost» AND «elderly» were used to search for comparative studies of the economic burden of dehydration. A total of 15 papers were identified.

RESULTS

Dehydration in the elderly is an independent factor of higher health care expenditures. It is directly associated with an increase in hospital mortality, as well as with an increase in the utilization of ICU, short and long term care facilities, readmission rates and hospital resources, especially among those with moderate to severe hyponatremia.

CONCLUSIONS

Dehydration represents a potential target for intervention to reduce healthcare expenditures and improve patients' quality of life.

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.

Morphometric changes in lateral ventricles of patients with recent-onset type 2 diabetes mellitus

It is becoming increasingly evident that type 2 diabetes mellitus can have effects on global and regional brain morphology. Ventricular enlargement reflecting cerebral atrophy has been reported particularly in elderly type 2 diabetes patients. However, little is known about its timing through the disease course and morphological variability. Using the combined volumetric and advanced three-dimensional morphological approach, we identified differences in size and shape of the lateral ventricles between recent-onset type 2 diabetes patients and healthy individuals. High-resolution T1-weighted images were obtained from 23 type 2 diabetes patients whose illness duration was less than 1 year and 23 carefully matched healthy individuals. By volume measurement, we found enlarged lateral and third ventricles in type 2 diabetes patients, relative to healthy individuals (F_1,41 = 7.96, P = 0.007; F_1,41 = 11.16, P = 0.002, respectively). Morphological analysis revealed that the expansion of lateral ventricles in the diabetic brain was prominent in the bilateral frontal horns. The current findings suggest that atrophic changes particularly of the anterior frontal lobe can occur as early as the first year after the clinical diagnosis of type 2 diabetes mellitus.

[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.

Interpreting routine biochemistry in those aged over 65 years: a time for change

In clinical practice, routine biochemistry tests are often performed for diagnostic or screening purposes. We reviewed papers that have reported reference values for people older than 65 years with or without overt health problems. Wider intervals have generally been reported for sodium, potassium, calcium and C-reactive protein (CRP) in the elderly. Higher levels of creatinine and lower levels of total cholesterol (TC) and serum albumin (SA) are observed with ageing. Elderly people have been found to be at greater risk for overt abnormalities in sodium, potassium, creatinine, TC, SA and CRP. The consequences of these abnormalities could be severe. For instance, even mild hyponatremia was associated with increased risk of mortality, disability and myocardial infarction. Mild hypernatremia was associated with severe disability. Mild increases in CRP levels were associated with an increased risk of sarcopenia, disability, cardiovascular disease and cognitive decline. Mild decreases in TC levels were associated with an increased risk of disability or mortality, and mild decreases in SA were associated with an increased risk of mortality, disability, sarcopenia and frailty. Nutritional factors could not wholly explain these effects. Modified biochemical reference values are required for elderly patients, as biochemical results can serve as markers of vulnerability to age-related diseases, linked to metabolism. Careful diagnosis and corrective interventions are needed for patients in this age group.

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.

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.

Strategies for Ensuring Good Hydration in the Elderly

Dehydration is a frequent etiology of morbidity and mortality in elderly people. It causes the hospitalization of many patients and its outcome may be fatal. Indeed, dehydration is often linked to infection, and if it is overlooked, mortality may be over 50%. Older individuals have been shown to have a higher risk of developing dehydration than younger adults. Modifications in water metabolism with aging and fluid imbalance in the frail elderly are the main factors to consider in the prevention of dehydration. Particularly, a decrease in the fat free mass, which is hydrated and contains 73% water, is observed in the elderly due to losses in muscular mass, total body water, and bone mass. Since water intake is mainly stimulated by thirst, and since the thirst sensation decreases with aging, risk factors for dehydration are those that lead to a loss of autonomy or a loss of cognitive function that limit the access to beverages. The prevention of dehydration must be multidisciplinary. Caregivers and health care professionals should be constantly aware of the risk factors and signs of dehydration in elderly patients. Strategies to maintain normal hydration should comprise practical approaches to induce the elderly to drink enough. This can be accomplished by frequent encouragement to drink, by offering a wide variety of beverages, by advising to drink often rather than large amounts, and by adaptation of the environment and medications as necessary.

Early identification of hypovolemia using total body resistance measurements in long-term care facility residents

BACKGROUND

Clinical management of fluid imbalance continues to be a major challenge in the long-term care industry. A proactive method of recognizing hypovolemia (reduced total body fluid) in its early stages is greatly needed.

OBJECTIVES

The goals of this research were 3-fold: (1) to determine the mean total body resistance(TBR) of an unmatched population of long-term care facility (LTCF) residents and correlate increased levels of TBR with evidence of fluid imbalance; (2) to identify patients at risk for hypovolemia by using TBR measurements as an objective guide; and (3) to suggest nursing practices designed to increase hydration in LTCF residents.

METHODS

Two pairs of electrocardiograph-type electrodes were placed on the right humeral-carpal junction and at the level of the right lateral malleolus of each patient. A 50-kHz signal was introduced to the outer electrode of each pair; the inner electrode detected variation of the resistance to the signal as a function of ionic conduction through the electrolyte content of body fluids. Resistance, reactance, and phase angle were measured.

RESULTS

The medical records of patients in 26 LTCFs (17 urban, 9 rural) in north-central and east Texas were reviewed during 2001. The mean age of the 1225 study patients (754 women, 471 men) was 76 years; mean height was 165.8 cm, and mean body weight was 71.9 kg. The mean TBR (right wrist-right ankle) for men and women was 504.81 ohms. Based on this measurement and a measurement of 629 ohms in residents judged to be hypovolemic on the basis of abnormal clinical laboratory data, patients with a wrist-ankle resistance >550 ohms were considered at risk for hypovolemia and possibly clinically significant dehydration. Subsequent measurements of TBR revealed a reduction consistent with levels in the normal range.

CONCLUSIONS

In these studies, TBR measurements correlated inversely with total body water and fluid compartments. Extracellular fluid compartments were found to be larger in females than in males, reflecting larger cellular mass in males. Total body resistivity was found to be higher in females than in males, which may have implications for body composition metrics. TBR provides a reference for comparison with both clinical and laboratory findings. The ability to identify LTCF residents at risk for hypovolemia, using noninvasive bedside measurements, may offer a definitive guideline for management of adequate fluid balance.

Changes in eating behavior during the aging process

The changing demographics of the world population necessitate a review of normative eating behavior in order to better differentiate eating pathologies from age-associated changes. This review examines the psychological, social, and physiological changes in aging as they affect eating behavior. Neurochemical and neurophysiological bases of appetite, psychobehavioral models of eating, and concomitant variables of depression, bereavement, and social interactions are examined. As many sensory systems decline with aging, these declines influence food choice and acceptability and may manifest conditions such as geriatric anorexia. Special circumstances of centenarians are discussed to provide further insights into pathological, normative, and superlative aging.

Cognitive Impairment in Heart Failure: Issues of Measurement and Etiology

• Background Clinicians need easy methods of screening for cognitive impairment in patients with heart failure. If correlates of cognitive impairment could be identified, more patients with early cognitive impairment could be treated before the problem interfered with adherence to treatment.

• Objectives To describe cognitive impairment in patients with heart failure, to explore the usefulness of 4 measures of cognitive impairment, and to assess correlates of cognitive impairment.

• Methods A descriptive, correlational design was used. Four screening measures of cognition were assessed in 42 patients with heart failure: Commands subtest and Complex Ideational Material subtest of the Boston Diagnostic Aphasia Examination, Mini-Mental State Examination, and Draw-a-Clock Test. Cognitive impairment was defined as performance less than the standardized (T-score) cutoff point on at least 1 of the 4 measures. Possible correlates of cognitive impairment included age, education, hypotension, fluid overload (serum osmolality &lt;269 mOsm/kg), and dehydration (serum osmolality ≥295 mOsm/kg).

• Results Cognitive impairment was detected in 12 (28.6%) of 42 participants. The 4 screening tests varied in effectiveness, but the Draw-a-Clock Test indicated impairment in 50% of the 12 impaired patients. A summed standardized score for the 4 measures was not significantly associated with age, education, hypotension, fluid overload, or dehydration in this sample.

• Conclusions Cognitive impairment is relatively common in patients with heart failure. The Draw-a-Clock Test was most useful in detecting cognitive impairment, although it cannot be used to detect problems with verbal learning or delayed recall and should not be used as the sole screening method for patients with heart failure. Correlates of cognitive impairment require further study.

An intervention to increase fluid intake in nursing home residents: prompting and preference compliance

OBJECTIVE

To evaluate a three-phase, behavioral intervention to improve fluid intake in nursing home (NH) residents.

DESIGN

Controlled clinical intervention trial.

SETTING

Two community NHs.

PARTICIPANTS

Sixty-three incontinent NH residents.

INTERVENTION

Participants were randomized into intervention and control groups. The intervention consisted of three phases for a total of 32 weeks: (1) 16 weeks of four verbal prompts to drink per day, in between meals; (2) 8 weeks of eight verbal prompts per day, in between meals; and (3) 8 weeks of eight verbal prompts per day, in between meals, plus compliance with participant beverage preferences.

MEASUREMENTS

Between-meal fluid intake was measured in ounces by research staff during all three phases of the intervention. Percentage of fluids consumed during meals was also estimated by research staff for a total of nine meals per participant (3 consecutive days) at baseline and at 8 and 32 weeks into the intervention. Serum osmolality, blood urea nitrogen, and creatinine values were obtained for all participants in one of the two sites at the same three time points.

RESULTS

The majority (78%) of participants increased their fluid intake between meals in response to the increase in verbal prompts (phase 1 to 2). A subset of residents (21%), however, only increased their fluid intake in response to beverage preference compliance (phase 3). There was a significant reduction in the proportion of intervention participants who had laboratory values indicative of dehydration compared with the control participants. Cognitive and nutritional status were predictive of residents' responsiveness to the intervention.

CONCLUSIONS

A behavioral intervention that consists of verbal prompts and beverage preference compliance was effective in increasing fluid intake among most of a sample of incontinent NH residents. Verbal prompting alone was effective in improving fluid intake in the more cognitively impaired residents, whereas preference compliance was needed to increase fluid intake among less cognitively impaired NH residents.

Dehydration: hazards and benefits

Dehydration is a serious risk for elders because total body water decreases with age, aging kidneys are less able to concentrate urine, and the sensation of thirst decreases. Geriatric nurses traditionally have assessed for dehydration, but its signs are difficult to detect in many patients. Instead, nurses, assistive personnel, and family members must work to prevent dehydration in elders. In contrast, dehydration may be beneficial to patients during the final stage of a terminal illness, although the decision to withhold or withdraw medical hydration may present a legal and ethical dilemma for nurses.

Dehydration: biological considerations, age-related changes, and risk factors in older adults

Maintenance of water balance is essential to normal physiologic function and vigorous aging. Older adults, however, frequently experience alterations in fluid homeostasis, which result in dehydration. This article describes the physiology of water balance, age-related changes that influence fluid regulation, and associated risk factors for dehydration in older adults. Fluid hygiene is an important health promotion activity for this age group, but when efforts to prevent imbalance are unsuccessful, early identification and intervention to correct problems should be done to minimize adverse consequences. Although much is known about fluid homeostasis, dehydration, and contributory factors in the aging process, water disorders remain prevalent in this group. A great deal of work is still needed to determine "best practices" and creative clinical interventions to support adequate fluid intake behaviors. Both quality management programs and research studies provide avenues for systematic evaluation.

What is the quality of the reporting of research ethics in publications of nursing home research?

OBJECTIVE

To assess the quality of reporting of research ethics in published clinical research that involves a particularly vulnerable population: nursing home residents.

DESIGN

A structured review of publications researched from 1992 to 1996 that involve nursing home residents. The review instrument assessed each publication's compliance with four common standards for research that involves nursing home residents or the cognitively impaired: justification of the use of nursing home residents, Institutional Review Board (IRB) review, nursing home committee review, and informed consent. For each publication, these results were summed into a quality score. The research ethics requirements contained in the journals' instructions for authors that corresponded with each publication were categorized in order to compare whether an association exists between the average quality score for each category and the detail of its research ethics instructions.

RESULTS

Forty-five publications were identified. The four quality measures of research ethics showed that (1) all 45 publications reported justification of use of nursing home residents, (2) 36 publications reported that informed consent was obtained or waived, (3) 18 publications reported IRB review, and (4) six publications reported nursing home committee review. Of the 35 publications reporting informed consent was obtained, 16 reported assessing subjects' decisional capacity, and 24 reported whether cognitively impaired subjects were included (19) or excluded (5). The research ethics requirements of each publication's instructions for authors ranked it in one of four categories: (A) None (9); (B) Less than "Uniform Requirements (UR) for Manuscripts Submitted to Biomedical Journals" (7); (C) UR (24); (D) UR plus Additional Instructions (5). A positive association exists between the detail of a research ethics instructions category and the average research ethics quality score for each category (Kruskal-Wallis chi2 = 11.2, P = .01). That is, the more detailed the instructions, the greater the quality score.

CONCLUSION

In publications of research that involves nursing home residents, basic standards of research ethics are not typically reported. However, the positive association between research ethics instructions category and research ethics quality score suggests that a journal's instructions for authors or other features of peer review and editing can affect the quality of reporting research ethics.

Effects of hypertonicity on water intake in the elderly: an age-related failure

Dehydration is a common clinical syndrome associated with many illnesses and treatments in the elderly. Prior studies have shown diminished sensation of thirst during water deprivation. It is currently unclear whether age-related decreases in thirst perception impair the defense against a hyperosmolar challenge. To examine the impact of water ingestion during hyperosmolality, young and old subjects were allowed free access to water during and after an intravenous infusion of 5% hypertonic saline. Cumulative water intake and serum osmolality were compared between seven healthy young (20-28 yrs) and seven healthy old (72-89 yrs) volunteers during and following a two hour hypertonic saline infusion at a rate of 0.06 mlxkg(-1) min(-1). Serum osmolality and water intake were markedly different between the two groups. In the old group, serum osmolality increased by 17 mosmol/kg above baseline despite free access to water. In contrast, serum osmolality increased to only 7 mosmol/kg above baseline in the young group and did not rise further. By ingesting water, the young were able to defend against an additional increase in serum osmolality. The young drank approximately twice that of the old during the infusion period. Healthy older individuals drink less than young despite a significantly increased serum osmolality. This hypodipsia in old individuals increases their susceptibility to hypertonicity.

Validation of multi-frequency bioelectrical impedance analysis in detecting changes in fluid balance of geriatric patients

OBJECTIVES

Multi-Frequency Bioelectrical Impedance Analysis (MFBIA) is a quick, simple, and inexpensive method to assess body fluid compartments. This study aimed at determining the validity of MFBIA in detecting clinically relevant changes of fluid balance in geriatric patients.

DESIGN

A prospective, observational study.

SETTING

The 22-bed Geriatric Department of the University Hospital Nijmegen.

PARTICIPANTS

Hospitalized patients were eligible if they did not have a pacemaker, were not suffering from terminal illnesses, and did not have psychogeriatric diseases likely to interfere with capacity to consent or comply. During a 16-months period, 218 patients were admitted, of whom 78 patients were eligible and 53 consented to participate.

MEASUREMENTS

Each subject's fluid balance was diagnosed twice a week as dehydrated, overhydrated, or euvolemic, based on standardized physical examination, laboratory tests, and weight evaluation. Changes in fluid balance were quantified by measuring total body water (TBW) and extracellular fluid (ECF) applying deuterium- and bromide-dilution techniques. Impedance at 1, 5, 50, and 100 kHz and body weight were measured daily. Sensitivity and Guyatt's responsiveness indexes of MFBIA in detecting dehydration and overhydration were determined.

RESULTS

In total, 1071 MFBIA measurements were performed, during which 14 transitions from dehydration to euvolemia and 13 transitions from overhydration to euvolemia were monitored. Rehydration of dehydrated patients caused an increase in TBW and ECF of 3.4 +/- 1.8 L and 1.9 +/- 1.9 L, respectively, which resulted in significant decreases in impedance of 133 +/- 67 omega at 1 kHz and 93 +/- 61 omega at 100 kHz (P = .001). Treatment of overhydrated patients caused a TBW and ECF loss of 3.8 +/- 4.2 L and 3.1 +/- 3.8 L, respectively, which resulted in significant increases in impedance of 104 +/- 72 omega at 1 kHz and 81 +/- 68 omega at 100 kHz (P < .001). Sensitivity of a single MFBIA in diagnosing dehydration and overhydration was 14% and 17%, respectively. Responsiveness indexes of weighing and MFBIA for dehydration and overhydration were similar at all frequencies and greater than one.

CONCLUSION

The sensitivity of a single impedance measurement in detecting dehydration and overhydration was low. However, responsiveness of serial measurements to intra-individual changes in fluid balance was good. Therefore, this noninvasive technique may be used in clinical practice to improve monitoring fluid balance in geriatric patients, especially when daily weighing is difficult.