Dehydration is a common health care problem in geriatric patients. The complexity of socio-medical problems and the interaction of risk factors add to the problem. An understanding of the problem volume, pathophysiology, and diagnosis, should enable the geriatric nurse to design and implement an individualized intervention plan.
The aim of this thesis is to explore the pathophysiological basis of geriatric dehydration, risk factors, diagnosis, and the geriatric nurse role in assessment, diagnosis, and intervention.
The diagnosis of dehydration in elderly patients links to significant mortality and morbidity. US studies show that 17% of dehydrated elderly patients die within 30 days of admission, extending the rate to one year mortality rate it comes to 50%. As regards contribution to morbidity, geriatric dehydration, even when mild, affects other systems functions, and results in decreased mental ability (Vivanti 2007).
Because of the complexity of the geriatric patient, geriatrics focuses on marinating the elderly functionality in its simple form. The socio-medical problems influencing functionality are instability (frailty), cognitive problems, iatrogenesis, and nutritional problems (Morley 2006).
There are specific concepts that control evaluation of geriatric patients, first, disease presentation is often atypical in the elderly, especially as age advances, second, because of decreased physiologic reserve, symptoms often develop at earlier disease stages.
Third, because symptoms in older people are often due to multiple causes, the diagnostic law of parsimony (using diagnostic reasoning to frame a single diagnosis explaining a collection of signs and symptoms) often does not apply (Resnick and Dosa 2008).
Pathophysiological basis of geriatric dehydration
Contrary to popular opinion, thirst is not the primary driving force behind fluid consumption. In the healthy and non-stressed adult, behavioral and non-regulatory psychosocial factors are the major determinants of fluid ingestion.
However, under physiologically stressful or threatening conditions, homeostatic mechanisms are triggered that motivate an active search for fluids and encourage drinking. Thus, under normal circumstances, fluid intake is primarily voluntary and subject to appetitive control. In contrast, the maintenance of fluid balance under physiological or pathological stress is primarily a homeostatic.
Thirst mechanisms may therefore be classified as either homeostatic or non-homeostatic. In geriatrics, homeostatic mechanisms include plasma osmolarity, intravascular volume plasma rennin activity, peripheral and central vasopressin levels, and oropharyngeal metering.
Non-homeostatic mechanisms include hedonic (suitable or pleasing) qualities of fluid, palatability of drink and taste preferences, access and availability, psychosocial factors, lifestyle habits, social isolation, and functional ability (Wilson 2006).
Faes et al (2007) suggested specific risk factors for dehydration in the elderly. They suggested that females aging 85 or more with low body weight and lower responsiveness to thirst are prone to dehydration. They also suggested, from a functional viewpoint, that patients with poor mobility, comprehension or communication problems, with self-neglect behavior, and with oral fluid intake less than 1500 ml per day are at higher risk.
Iatrogenic dehydration may be secondary to diuretics or laxatives chronic use, high protein intake, or long fasting periods as preoperatively or pre lab testing. Finally disease related dehydration may occur in Alzheimer patients, patients who are afraid of incontinence, anorexia or patients with dysphagia.
Diagnosis of dehydration in geriatrics
Clinical diagnosis of dehydration is often unreliable. Symptoms are usually nonspecific such as lethargy, muscle weakness, dizziness, and confusion.
Physical examination may not as well conclude the diagnosis. Reduced skin turgor from dehydration is not easily distinguished from age-related cutaneous atrophy, dry oral mucous membranes in older patients are not necessarily indicative of systemic dehydration.
Similar changes occur with chronic mouth breathing, supplemental oxygen use, pathological xerostomia. Reliability of orthostatic systolic hypotension as an index of dehydration in older adults is confirmed in recent studies (Sandra and Reilly 2007).
Weight loss is a significant sign of dehydration. Generally, rapid and acute weight loss in excess of 3% of baseline body weight is most likely due to reduced total body water from dehydration. Overall, the detection of dehydration is largely dependent on a high threshold of suspicion.
Laboratory indices are often relied on to support the diagnosis of dehydration, assess severity, and guide intervention. Serum osmolarity >300, blood urea nitrogen (BUN) >20, or BUN: Creatinine ratio >20 are useful indices of dehydration (Wilson 2006).
The implication to nursing in diagnosis is a key to diagnosis; fluid balance charts documenting input and output are helpful in determining the risk and characterizing the severity of dehydration (Wilson, 2006).
Complications of dehydration in geriatrics
Reduced skin integrity due to subcutaneous dehydration may result in xerosis, pruritus, recurrent skin infections, and pressure ulcers in the immobile patient. Cystitis and urinary tract infections may result from the irritant effect of highly concentrated urine on the vesical mucosa.
Inspissated oral and gastrointestinal secretions can lead to constipation, impaction, xerostomia, periodontal sepsis, and mouth ulcers. Neurological dysfunction in dehydrated older adults may present as delirium, dizziness, recurrent falls, and subsequent complications such as hip fractures or traumatic brain injury (Vivanti et al 2008).
Nursing Assessment, diagnosis, and interventions
Knowing that there is no agreed on clinical definition of dehydration, dehydration is not an isolated condition nor does it manifest in one presentation, besides, there is no standard clinical dehydration assessment protocol, nursing assessment gains importance to achieve patient wellness (Vivanti et al 2008).
For assessment purposes, a geriatric nurse must differentiate between isotonic dehydration that is decreased intravascular, interstitial, and-or intracellular fluid water alone without change in sodium. When serum sodium changes by increase or decrease, the condition is hypertonic or hypotonic dehydration respectively (Wilson 2007).
Nursing assessment includes patient’s health history as regards specific disease states like renal or cardiovascular disease, psychiatric disorder like dementia or depression. Nursing assessment should also include the presence of comorbidities, or prescription drug intake (number, type, and dosage) (Wilson 2007).
Important physical signs that are significant indicators for geriatric dehydration are body mass index, orthostatic systolic hypotension, and baseline temperature and pulse rate and the urine color (Vivanti 2008).
Important laboratory tests to request and follow up are urine specific gravity, BUN-Creatinine ratio, serum sodium, and serum osmolarity. A geriatric nurse should include the patient’s fluid intake behavior in the assessment sheet (Wilson 2007).
Nursing diagnosis of a geriatric dehydrated patient
For nursing diagnosis, the problem should be targeted, assessed, aiming to determine the goals and objectives within a time frame and put an intervention plan (Doegene et al 2008). The first nursing diagnosis is impaired fluid (with or without electrolyte) balance.
The subjective characteristics for this diagnosis are the patient willingness to fluid intake and enhance fluid balance, and expressing the need to have fluids. Objectively, weight gain (without evidence of edema), moist mucous membranes, intake of daily needs, return of urine color and specific gravity to normal, and urine output becoming appropriate for intake are characteristic.
The outcome desired is hydration, and control the risk of potential complications. Planning the intervention within a time frame aiming at maintaining fluid volume at a functional level, monitor fluid balance to ensure hydration and avoid excessive hydration (Wakfield et al 2008).
The second nursing diagnosis is the risk for imbalanced body temperature, being risk diagnosis is not evidenced by signs and symptoms, as the problem has not occurred and nursing interventions are directed at prevention.
The desired outcomes are to eliminate or reduce actual, personal, and modifiable health threats predisposing to imbalanced body temperature including dehydration. Planning intervention should aim at maintaining body temperature within normal range, understanding of individual risk factors and appropriate interventions, and monitoring and maintaining appropriate body temperature (Doegene et al 2008).
Nursing interventions for a geriatric dehydrating patient
On implementing a fluid restorative program, the client’s preferred fluids should be noted, which will be frequently and regularly presented especially for bedridden patients. This is better done by having the patient to verbalize the appropriate choices; thus demonstrate the patient’s understanding of the condition, and facilitate maintenance of adequate hydration status.
As a preventive practice, the geriatric nurse is required to regularly and frequently monitor dehydrated clients for adequate fluid intake, which is best done using a fluid input-output sheet. It is advised to utilize medication time to communicate with the patient and encourage fluid intake. Intervention follow up and reassessment in a pre-determined time period (3 days) (Newfield 2007).
Patient and caregivers education is essential to preventive practice; education should target obtaining relevant information from food labels, which helps in making appropriate choices. It should also target adjustment of fluid intake in the lights of physical activity performed by the patient.
Essential to patient education is knowledge about the signs and symptoms of fluid imbalances like concentrated urine, dry mucous membranes, in cases of infection, and when to report to healthcare (Newfield et al 2007).
Dehydration is common in geriatric patients, mostly because they do not have enough fluid intake secondary to a complex interacting array of risk factors. Geriatric assessment is a multidisciplinary, multidimensional diagnostic tool, in this case, the nursing process is one of problem solving models, and designed as an individualized plan depending on the risk factors and patient’s status.
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