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.     

Hydration in older adults: The contribution of bioelectrical impedance analysis

Abstract

The sensory and gastrointestinal changes that occur with ageing affect older adults’ food and liquid intake. Any decreased liquid intake increases the risk for dehydration. This increased dehydration risk is compounded in older adults with dysphagia. The availability of a non-invasive and easily administered way to document hydration levels in older adults is critical, particularly for adults in residential care. This pilot study investigated the contribution of bioelectrical impedance analysis to measure hydration in 19 older women in residential care: 13 who viewed themselves as healthy and six with dysphagia. Mann-Whitney U analyses documented no significant between-group differences for Total Body Water (TBW), Fat Free Mass (FFM), Fat Mass (FM), and percentage Body Fat (%BF). However, when compared to previously published data for age-matched women, the TBW and FFM values of the two participant groups were notably less, and FM and %BF values were notably greater than expected. If results are confirmed through continued investigation, such findings may suggest that long-term care facilities are unique environments in which all older residents can be considered at-risk for dehydration and support the use of BIA as a non-invasive tool to assess and monitor their hydration status.     

Oral hydration in older adults: greater awareness is needed in preventing, recognizing, and treating dehydration

Maintaining adequate fluid balance is an essential component of health at every stage of life. Age-related changes make older adults more vulnerable to shifts in water balance that can result in overhydration or, more frequently, dehydration. This article reviews age-related changes, risk factors, assessment measures, and nursing interventions for dehydration.     

Tips on promoting food and fluid intake in the elderly

Nurses have a crucial role in ensuring adequate food and fluid intake in the elderly. Nurses can improve the nutritional intake of their elderly patients by obtaining proper nutritional assessments, addressing risk factors for malnutrition and fluid deficit, providing enough staff and volunteers to help feed impaired patients, honoring each older person's meal pattern, scheduling drug regimens that do not interfere with food and fluid intake, not scheduling food-related activities and visits too near mealtime, serving food that is palatable and attractively served, ensuring adequate fluid intake, and being creative in finding ways to keep the restless, wandering patient well-nourished and hydrated. Monitoring food and fluid intake requires precise recording of what foods and fluids the older person is ingesting, keeping accurate intake and output records, determining periodic weights, informing the physician of patients' weight loss in a timely manner, and instituting corrective measures at once.     

Comparison of four standards for determining adequate water intake of nursing home residents

Adequate hydration for nursing home residents is problematic. The purpose of this study was to compare four standards used to determine a recommended water intake among nursing home residents. Inconsistencies in the amount of water intake recommended based on the standards compared were identified. The standard based on height and weight provides the most individualized recommendation. An individualized recommendation would facilitate goal setting for the care plan of each older person and assist in the prevention of dehydration. It is essential that a cost-effective and clinically feasible approach to determine adequate water intake be determined for this population to prevent the adverse outcomes associated with dehydration.     

Unrecognized chronic dehydration in older adults: examining prevalence rate and risk factors

Dehydration has serious consequences for older adults, including increased risk of illness or death. This retrospective review of medical records describes the prevalence, assessment, and risk factors for chronic dehydration in 185 older adults who visited an emergency department in June 2000. Results showed chronic dehydration was present in 89 (48%) patients. Physicians documented assessment for signs of dehydration in 23 (26%) of the dehydrated older adults, but no independent assessments for dehydration were recorded by nurses. These findings indicate many older adults may suffer from unrecognized dehydration, and nurses should be alert to the possibility that dehydration may be present in community-dwelling older adults as well as those who live in residential facilities.     

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

AIM: This article reviews the literature on how important water is to the world's elderly population. BACKGROUND: Water is a finite resource, so we must preserve the water that we have. Physiological aspects and what water requirements our bodies maintain sum up this essential nutrient for life. Dehydration is a concern in the elderly. CONCLUSIONS: Five strategies related to water intake can promote health: (1) assess for symptoms which may indicate dehydration, (2) encourage ingestion of fluids and foods to maintain an optimal fluid level, (3) be alert to physical and clinical conditions affecting hydration in the elderly, (4) consider environmental factors which may affect body fluids, electrolytes and acid-base balance, and (5) encourage methods to increase fluid consumption.     

Use of hypodermoclysis to manage dehydration

Older people, particularly those who are frail, are vulnerable to dehydration. Management of dehydration in older people can be more complex than in younger adults because of the physical effects of ageing. As the population ages, nurses will increasingly care for older patients in every setting. This article provides an overview of the physiological changes that affect the ability of older people to maintain a normal fluid balance. Risk factors for dehydration are reviewed and strategies for the prevention, detection and management of dehydration are discussed. The article focuses on subcutaneous fluid replacement for the management of dehydration in older adults.     

Dehydration: why is it still a problem?

Reports from organisations such as the Care Quality Commission have identified many hospital patients, particularly older people, are suffering from dehydration. A range of national initiatives have emphasised the importance of hydration and nutrition, and offered guidance to help address shortcomings, yet the problems persist. This article examines the interplay of factors that affect the assessment and identification of dehydration, and its prevention. It also offers strategies to help nurses to ensure patients receive adequate hydration.     

Oral hydration during growth hormone stimulation with clonidine

The arginine-clonidine growth hormone (GH) stimulation test causes hypotension, requiring intravenous fluids to stabilize blood pressure (BP) and delaying departure from clinic. We hypothesized that oral hydration during the stimulation test would decrease need for intravenous fluids and shorten clinic stay. Children drank a diet electrolyte drink (10 ml/kg) on arrival to the test, which was repeated after clonidine. Fifteen children (7 girls) were tested without oral hydration, and 23 (6 girls) were tested with oral hydration (age range, 2-15 years). Compared with no oral hydration, intake of >13 ml/kg rarely required intravenous fluids, improved diastolic BP, and permitted discharge at the end of the GH test, with a higher BP.     

Minimal fetal renal pyelectasis

To assess the possible relationship between the degree of maternal hydration and the sonographic identification of minimal fetal renal pyelectasis, a prospective study was performed in which fetuses demonstrating mild dilation of the renal pelvis (maximum diameter ranging from 3 to 11 mm) were reexamined after the mothers refrained from oral intake for 12 hours. Complete or almost complete resolution of the pyelectasis occurred in only four of 17 kidneys (23.5 per cent) while the remaining fetal kidneys demonstrated little or no change in the degree of pyelectasis following maternal dehydration. This observation, as well as previous experimental research, suggests that the state of maternal oral hydration is not a major cause of minimal fetal pyelectasis. Additionally, the observation of fetal pyelectasis measuring at least 3 mm in greatest dimension is common, occurring in approximately 18 per cent of fetuses older than 24 menstrual weeks.     

Dehydration in dying patients: study with physicians in French-speaking Switzerland

We surveyed physicians in French-speaking Switzerland to assess the perception of suffering resulting from dehydration and its relation to the clinical choice between oral and artificial hydration. A questionnaire describing hypothetical cases of dehydration in an elderly terminal cancer patient in different clinical situations (conscious, demented, comatose) was sent to 978 physicians. The physicians were asked to assess the discomfort due to dehydration and the treatment they would propose in order to correct this situation (oral or artificial hydration). The return rate was 41%. The results show that there is no consensus with respect to the assessment of suffering (it gets a "low" score from 33% of replies and a "high" score from 41% of replies) or of thirst ("low": 30%, "high": 43%). Only 28% of the replies indicated artificial hydration for conscious patients while 44% chose this treatment for comatose patients. Physicians choosing artificial hydration were significantly more prone to consider suffering and thirst as "serious" than those preferring hydration by mouth. It can be concluded that two thirds of the physicians who responded think that artificial hydration is not the best way to respond to dehydration in dying patients. The choice depends partly on the assessment of the suffering and thirst resulting from terminal dehydration.     

Participation in daily living tasks among older adults with fear of falling.

OBJECTIVE: This study investigated patterns of participation in daily living tasks by older adults with fear of falling. The relationship between reported participation in a broad set of daily living tasks and the risk of falling involved in task performance--or activity-related risk--as judged by occupational therapists was examined. Further, several characteristics of older adults that have been associated with fear of falling were examined to determine which older adults had patterns of participation most strongly associated with the activity-related risk. METHOD: Thirty-eight occupational therapists were surveyed and asked to judge the activity-related risk in performing specific daily living tasks. Additional data were obtained from 339 older adults with fear of falling who participated in a previous study on the effectiveness of an intervention to reduce fear of falling. Older adults' participation in daily living tasks as measured by items of the Sickness Impact Profile was correlated with the judgments of activity-related risk controlling for potential confounding factors. Univariate regression analyses and t tests were used to determine whether several characteristics of older adults were associated with the relationship between participation and activity-related risk. RESULTS: Small to moderate significant relationships were found between older adults' participation in daily living tasks and the activity-related risk as judged by occupational therapists (r = -.25, p < .0001). Older adults with the lowest confidence in ability regarding falls had the strongest relationships. CONCLUSION: Activity-related risk is an aspect of daily living tasks that relates to participation in activities by older adults with fear of falling. Knowledge of the activity-related risk involved in daily living tasks can be used to facilitate occupational performance in clients with fear of falling and associated activity restriction.     

Gastroenteritis in Children: Part II. Prevention and Management

The treatment of gastroenteritis in children focuses on preventing dehydration. A child with minimal or no dehydration should be encouraged to continue his or her usual diet plus drink adequate fluids. Many studies have shown that a child's regular diet reduces the duration of diarrhea. Oral rehydration therapy with a rehydration solution can be used to treat diarrhea in children with mild to moderate dehydration. Ondansetron can decrease vomiting or help avoid the need for intravenous fluid, but it increases episodes of diarrhea. Probiotics can be used to shorten the course of diarrhea. Good handwashing reduces the incidence of acute gastroenteritis, but not rotavirus. The introduction of two rotavirus vaccines in the United States in 2006 significantly reduced the incidence of rotavirus gastroenteritis. The oral, live vaccines have strong safety records, despite a minimal incidence of intussusception.     

Emergency Department Treatment of Viral Gastritis Using Intravenous Ondansetron or Dexamethasone in Children

Objectives To compare the efficacy of intravenous ondansetron or dexamethasone compared with intravenous fluid therapy alone in children presenting to the emergency department with refractory vomiting from viral gastritis who had failed attempts at oral hydration. Methods This double‐blind, randomized, controlled trial was performed in a tertiary care pediatric emergency department. Children aged 6 months to 12 years presenting with more than three episodes of vomiting in the past 24 hours, mild/moderate dehydration, and failed oral hydration were included. Patients with other medical causes were excluded. Subjects were randomized to dexamethasone 1 mg/kg (15 mg maximum), ondansetron 0.15 mg/kg, or placebo (normal saline [NS], 10 mL). All subjects also received intravenous NS at 10–20 mL/kg/hr. Oral fluid tolerance was evaluated at two and four hours. Those not tolerating oral fluids at four hours were admitted. Discharged patients were evaluated at 24 and 72 hours for vomiting and repeat health care visits. The primary study outcome was hospitalization rates between the groups. Data were analyzed using chi‐square test, Kruskal–Wallis test, Mantel–Haenszel test, and analysis of variance, with p < 0.05 considered significant. Results A total of 166 subjects were enrolled; data for analysis were available for 44 NS‐treated patients, 46 ondansetron‐treated patients, and 47 dexamethasone‐treated patients. Hospital admission occurred in nine patients (20.5%) receiving placebo (NS alone), two patients (4.4%) receiving ondansetron, and seven patients (14.9%) receiving dexamethasone, with ondansetron significantly different from placebo (p = 0.02). Similarly, at two hours, more ondansetron‐treated patients (39 [86.6%]) tolerated oral hydration than NS‐treated patients (29 [67.4%]; relative risk, 1.28; 95% confidence interval = 1.02 to 1.68). There were no differences in number of mean episodes of vomiting or repeat visits to health care at 24 and 72 hours in the ondansetron, dexamethasone, or NS groups. Conclusions In children with dehydration secondary to vomiting from acute viral gastritis, ondansetron with intravenous rehydration improves tolerance of oral fluids after two hours and reduces the hospital admission rate when compared with intravenous rehydration with or without dexamethasone.     

Postadmission Dehydration: Risk Factors,Indicators, and Outcomes

Detecting and treating dehydration in hospitalized patients is critical because of the adverse outcomes associated with this condition. Using a case‐control design, this study estimated the incidence, risk factors, and outcomes of dehydration in hospitalized adults. The overall incidence rate for developing one of three ICD‐9 codes for dehydration during a hospital stay was 3.5%. Cases and controls differed significantly on a number of clinical variables on admission; a large percentage of patients may have had dehydration on admission to the hospital. Mortality rates at 30 and 180 days postdischarge were significantly higher when dehydration was present. Patients may be discharged to rehabilitation settings in a dehydrated state, which prolongs recovery. Despite the increased risk for dehydration and higher rates of hospitalization in older populations, little systematic research has addressed the risk factors for and indicators of dehydration in hospitalized patients.     

Inadequate fluid intake in long term care residents: prevalence and determinants

Dehydration is estimated to be present in half of long term care residents, as many do not consume the recommended levels of fluid intake. This study aims to describe fluid intake in long term care residents and identify the factors associated with fluid intake. Data were collected from 622 long term care residents, with a mean age of 86.8?±?7.8. Total fluid intake was estimated over three non-consecutive days. Potential resident and unit-level variables risk factors for low fluid intake were collected, such as dementia status, activities of daily living, and eating challenges. Average daily fluid intake ranged from 311–2390?mL (1104.1?±?379.3). Hierarchical regression analysis revealed that fluid intake was negatively associated with increased age, cognitive impairment, eating challenges and increased dining room staffing. Being male and requiring more physical assistance were positively associated with intake. Variables identified to predict intake could help inform strategies and targeted interventions to improve fluid intake.     

Keeping nursing home residents hydrated

The purpose of this research is to ascertain nursing home (NH) staffs' perspectives of the problem of dehydration in NHs (skilled nursing facilities) and have them identify clinically practical interventions to ensure that NH residents consistently take adequate fluids. Four focus groups with 28 NH staff members in attendance are held in three NHs in metropolitan Los Angeles. The majority of participants are certified nursing assistants; however, licensed vocational nurses, registered nurses, and other NH staff also attend the groups. Content analytic techniques are used to analyze the data. Three themes emerge focusing on residents' reasons for not drinking, signs and symptoms of dehydration, and strategies for improving hydration in NH residents. NH staff members identify the complexity of providing adequate hydration that was influenced by the resident's relationship with family and NH staff and communication between staff members.     

Gastrointestinal dysfunction in the critically ill: nutritional implications

Parenteral therapy is frequently indicated for initial repletion in the severely malnourished patient. Attention should be paid to the nutrients required for initial repletion based on the patient's metabolic needs at the time of therapy, as well as allowance for adequate calories for repletion of body and muscle mass. After the initiation of parenteral therapy and the adequate replacement of fluids and electrolytes, slow introduction of oral or enteric feeding is reasonable. This probably is best handled initially by the use of a nasogastric or nasoenteric feeding tube. However, if the patient willingly ingests oral feedings, the oral route is certainly favorable. Close attention should be paid to the adequacy of gastric emptying. Symptoms of abdominal bloating and diarrhea may require modification of the rate at which oral intake is progressing.