What could be an undesired effect of a patient Overhydration prior to or during sample collection?

Nutr Healthy Aging. 2017; 4[3]: 227–237.

Published online 2017 Dec 7. Prepublished online 2017 Jul 8. doi: 10.3233/NHA-170026

Abstract

BACKGROUND:

Inadequate hydration in the elderly is associated with increased morbidity and mortality. However, few studies have addressed the knowledge of elderly individuals regarding hydration in health and disease. Gaps in health literacy have been identified as a critical component in health maintenance, and promoting health literacy should improve outcomes related to hydration associated illnesses in the elderly.

METHODS:

We administered an anonymous survey to community-dwelling elderly [n = 170] to gauge their hydration knowledge.

RESULTS:

About 56% of respondents reported consuming >6 glasses of fluid/day, whereas 9% reported drinking ≤3 glasses. About 60% of respondents overestimated the amount of fluid loss at which moderately severe dehydration symptoms occur, and 60% did not know fever can cause dehydration. Roughly 1/3 were not aware that fluid overload occurs in heart failure [35%] or kidney failure [32%]. A majority of respondents were not aware that improper hydration or changes in hydration status can result in confusion, seizures, or death.

CONCLUSIONS:

Overall, our study demonstrated that there were significant deficiencies in hydration health literacy among elderly. Appropriate education and attention to hydration may improve quality of life, reduce hospitalizations and the economic burden related to hydration-associated morbidity and mortality.

Keywords: Dehydration, aged, health literacy, hypernatremia, hyponatremia

1. Introduction

A number of common hydration-related medical conditions in the geriatric population are associated with either excess total body fluid [overhydration], or reduced total body fluid [dehydration] [1–10]. Dehydration occurs when there is excess fluid loss from the body, either due to an illness, exposure to high temperatures, exertion with inadequate fluid intake or use of diuretic medications. This can result in serious imbalance of sodium ranging from hypo to hypernatremia which if not treated promptly, could result in significant morbidity and mortality [1, 4–6]. The symptoms of dehydration can range from simple dizziness and confusion to seizures and death. Some of the physical signs of dehydration that have demonstrated good specificity for detection include dry axillae, sunken eyes, and a delayed capillary refill time [2, 3].

In some individuals, the loss of as little as 2-3% of body fluid can cause physical and cognitive impairment [4]. The elderly population is at an increased risk for dehydration for a number of reasons, including a decrease in the thirst sensation, a decrease in renal perfusion, an altered sensitivity to antidiuretic hormone and neurocognitive deficits [1, 4–7] Notably, Rowat et al. identified 4 independent risk factors for dehydration upon admission to a hospital: 1] older age, 2] female gender, 3] total anterior circulation syndrome, and 4] prescribed diuretics [8].

Clinically, dehydration is a major predictor of morbidity and mortality in admitted patients [8, 9]. Rowat et al. assessed dehydration in hospitalized stroke patients and discovered that dehydrated patients were significantly more likely than hydrated patients to become dependent upon others at discharge or die during hospitalization [8]. Dehydration following a stroke also increases the risk of venous thromboembolism, and this is associated with poor health outcomes [8].

In addition to thromboembolism, there are numerous other consequences of dehydration among the elderly population, including delirium, confusion, infections, falls, and fractures [10–12]. Lastly, Hodgkinson et al. found that semi-independent patients in nursing homes who appear to be capable of obtaining their own fluids, but who cannot do so in practice, are most at risk for dehydration [13]. It is estimated that cognitively impaired residents in nursing facilities are at the highest risk of dehydration and more than one-third suffer from dehydration [14, 15]. In these cases, healthcare professionals do not present these patients with fluids because they do not perceive this group as being at risk for dehydration [15].

Dehydration also presents a tremendous economic burden some of which is potentially preventable [16]. A large retrospective study using the Healthcare Cost and Utilization Project [HCUP] project data revealed that the average age for patients admitted with the principal diagnosis of dehydration was 80.4 years. Approximately 64% of these were community dwelling white women [17]. The average length of stay [LOS] for dehydration in the HCUP data was 4.6 days and the total hospitalization charge per person was $7,442 [17].

The elderly population is also at risk for overhydration. Overhydration, or fluid overload, is caused by a number of conditions, including heart failure [18, 19], kidney failure [20, 21], and protein deficiency [22]. Iatrogenic overhydration can also occur as a result of receiving intravenous fluids [23], blood transfusions [24], and steroids [25]. The consequences of overhydration range from mild to life-threatening and include congestive heart failure and pulmonary edema, [26–28], confusion [29, 30], high blood pressure, seizure, and even death [31, 32].

The electrolyte abnormalities in elderly surgical patients and critically ill are often due to overhydration secondary to excess or inappropriate infusion of intravenous fluids [32–34]. Hence, overhydration is an independent risk factor for morbidity and mortality in elderly people with heart failure, acute or chronic renal failure or for those on dialysis [4, 5, 33, 34].

Despite numerous studies that describe why the elderly population is at an increased risk for hydration-related health issues compared to the younger population, there is little information on how much fluid elderly people consume or the health literacy of this population about proper hydration [13]. One of the few studies that investigated this, Goodman et al., concluded from the National Cancer Institute’s 2007 Food Attitudes and Behaviors Survey that a significantly greater number of individuals 55 years of age or older drink fewer than 4 cups of water per day compared to individuals between 18 and 34 years old [47% vs. 43%, p = 0.04] [35, 36]. This finding supported those of Sebastian et al. who found that while those 20–39 years of age reported drinking 4.7–5 cups of water/day, those 60+ years old reported drinking only 3.1–3.5 cups/day [37, 38]. While these data indicate that the elderly population consumes less water than the younger population, more work needs to be done to determine the specific amount of fluid that the elderly consume and to understand the elderly population’s general knowledge of hydration. In addition, there has been minimal research into how well elderly individuals understand the signs and symptoms of dehydration and overhydration.

Since the elderly are highly susceptible to problems associated with hydration, we conducted a survey to understand how much fluid elderly individuals consume on a daily basis and to determine their knowledge about optimal hydration status, the signs and symptoms of dehydration and overhydration, and some of the common associated medical conditions.

2. Materials and methods

2.1. Design

This was a cross-sectional study based using an anonymous survey and a convenience sample methodology. The questionnaire was designed to evaluate the health literacy of older adults in the geriatric age-group regarding the importance of hydration in health and different common disease conditions encountered in the elderly. The survey comprised of 5 demographic questions and 10 structured hydration related questions which addressed types and quantity of fluids consumed, the importance of hydration for health and the problems associated with dehydration or overhydration [Fig. 1]. The study was approved by the Institutional Review Board at the University of Arkansas for Medical Sciences [UAMS] [IRB protocol #202655].

Hydration questionnaire utilized in the study. Demographic questions have not been included in this figure.

2.2. Subjects

The survey was completed by 170 elderly, community-dwelling individuals [over the age of 60] who were patients at the Thomas and Lyon Longevity Clinic at the UAMS Reynolds Institute on Aging. A trained research technician administered the survey to participants. The participants either completed the survey themselves or the research technician read the questions and possible answers to them, and the participant indicated the answers verbally.

2.3. Analysis

The survey results were analyzed with SAS software [version 9.3, SAS Institute Inc.]. Categorical variables are presented as counts and percentages that were calculated with the PROC FREQ SAS procedure. Responses to questions were compared by group with either the chi-square test or Fisher’s exact test for contingency tables with cells having expected frequencies of 5 or less. The chi-square and Fisher’s exact tests were performed with the PROC FREQ SAS procedure with the options “chisq” and “fisher.” The α cut-off for significance was accepted as p < 0.05.

3. Results

3.1. Study participants

The demographic characteristics of the participants are detailed in Table 1. All of the survey respondents were community-dwelling, and most lived in the Central Arkansas area. The majority of survey respondents [57%] were between 70 and 79 years old, 80% were White, Non-Hispanic, and 20% were African Americans. There were 52% females. The majority were college graduates or greater [57%], but 35% had less than a high school education.

Table 1

Demographics [n = 170]

3.2. Fluid intake

Our survey began by gauging how much and what type of fluid the participants consumed each day through recall of fluid intake on an average day. We found that the majority of respondents [56%] drank more than 6 glasses of fluid each day, with 15% drinking 9 or more glasses [Fig. 2A]. Over 35% reported drinking at least 4 to 6 glasses each day, and only 9% drank 3 glasses or fewer [Fig. 2A].

Self-reported A] amounts and B] types of fluids the survey respondents consumed per day. Most respondents consumed 4–9 glasses of fluid per day, and the most popular drinks were water and coffee. “Other” drinks included milk, fruit and vegetable juices, and alcoholic beverages [e.g. beer or wine].

When asked about the kinds of fluids they drank, 90% reported drinking water, 66% drank coffee, and 47% drank tea [Fig. 2B]. Only 22% reported drinking soda [e.g., Coke or Pepsi] [Fig. 2B]. With respect to other kinds of fluids, about 12% of respondents mentioned drinking milk, fruit or vegetable juice and alcoholic beverages [e.g., beer or wine].

3.3. Importance of hydration

We next determined how much each participant knew about the importance of fluid intake for the function of the body. The majority of respondents [79%] were aware that adequate fluid intake was important for eliminating waste from the body, and at least 60% of respondents had significant knowledge about hydration to identify that cooling of the body, metabolism, and maintaining good circulation were related to adequate fluid intake [p < 0.05, Fig. 3A].

Survey respondents were asked about A] The importance of adequate fluid intake for bodily function. About 60–80% displayed sufficient hydration literacy regarding specific body functions requiring adequate fluid intake. B] Only 34% of respondents were able to correctly answer at what percentage of fluid loss dehydration signs and symptoms would begin to appear. *P-value