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Thirst in the elderly with and without heart failure
Archives of Gerontology and Geriatrics 53 (2011) 174–178
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Thirst in the elderly with and without heart failure Nana Waldre´us a,*, Fredrik Sjo¨strand b, Robert G. Hahn a,c a
Department of Research, House 10, 3rd Floor, So¨derta¨lje Hospital SE-152 86 So¨derta¨lje, Sweden Department of Clinical Science and Education, Karolinska Institutet, So¨dersjukhuset, SE-118 83 Stockholm, Sweden c Faculty of Health Sciences, Linko¨ping University, SE-581 85 Linko¨ping, Sweden b
A R T I C L E I N F O
A B S T R A C T
Article history: Received 3 June 2010 Received in revised form 27 September 2010 Accepted 28 September 2010 Available online 28 October 2010
Elderly patients with heart failure (HF) may be troubled by thirst, despite the fact that elderly have an impaired ability to sense thirst. The present study was undertaken to compare the intensity of thirst in patients with and without HF and to evaluate how this symptom relates to the health-related quality of life and indices of the fluid balance. Forty-eight patients (mean age 80 years) admitted to hospital with worsening HF (n = 23) or with other acute illness (n = 25) graded their thirst and estimated their healthrelated quality of life (HRQoL). Serum sodium was measured and urine samples were assessed for color and electrolyte content. The HF patients reported significantly more intensive thirst (median = 75 mm) compared with those in the control group (median = 25 mm; p < 0.0001). There was no statistically significant relationship between thirst and HRQoL, which was low overall. Serum sodium and urine color did not differ significantly between the groups, but the urine of the HF patients had a lower sodium concentration and osmolality. We conclude that elderly patients with worsening HF have considerably increased thirst and, hence, intense thirst should be regarded as a symptom of HF. ß 2010 Elsevier Ireland Ltd. All rights reserved.
Keywords: Thirst of elderly Aged heart failure patients Quality of life Dehydration
1. Introduction HF is a progressive, complex clinical syndrome featured by gradual development of symptoms like dyspnoe, fatigue and peripheral edema. The overall prevalence of HF is increasing not only because of aging of the population but also because of successful treatment of cardiovascular diseases (Dickstein et al., 2008). Structural and/or functional cardiac disorders that impair systolic and/or diastolic ventricular function lead to inability of the heart to pump blood with normal filling pressures. This elicits a hormonal cascade which acts to retain sodium and water in the body (So¨derberg et al., 2001; Sergi et al., 2004) although experience holds that many of these patients still complain of excessive thirst (Nordgren and So¨rensen, 2003; Bra¨nnstro¨m et al., 2006; Falk et al., 2007; Holst et al., 2008). This symptom may also seem paradoxical considering that the ability to sense thirst is impaired in the elderly (Rolls and Phillips, 1990; Stachenfeld et al., 1997; Farrell et al., 2008). The relationship between fluid balance and thirst is well studied in young and healthy individuals (Sewards and Sewards, 2000), but rarely in the elderly. Moreover, it is essentially unknown if frequent events with excessive thirst affect the QoL. The purpose of the present study was to compare the intensity of the thirst experience in a group of elderly patients admitted to
* Corresponding author. Tel.: +46 76 774 5199; fax: +46 8 5502 4375. E-mail address: [email protected] (N. Waldre´us). 0167-4943/$ – see front matter ß 2010 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.archger.2010.10.003
hospital due to aggravated HF with those admitted to the same hospital due to other diseases. We also evaluated how thirst affects the HRQoL, and if worsening of HF can be indicated by a urine color chart (Armstrong et al., 1998). 2. Subjects and methods 2.1. Design and setting This open controlled study was performed at the Departments of Internal Medicine and Geriatrics at a middle-sized hospital in the county of Stockholm, Sweden. The local Ethics Committee of Stockholm had approved the study, which complied with the Declaration of Helsinki, and each patient gave his/her informed consent for participation. 2.2. Study cohort Forty-eight patients (65 years of age) were consecutively enrolled and arranged into two groups, depending on the presence of HF. Patients with diabetes or in the end of life with symptom relieving treatment alone were excluded. In the HF group, the patients had just been admitted to hospital due to the worsening of previously known HF, which was their main diagnosis. All patients in the control group had been admitted to the Department of Geriatrics to receive treatment for acute illness, but none of them had been diagnosed with HF.
N. Waldre´us et al. / Archives of Gerontology and Geriatrics 53 (2011) 174–178
2.3. Data collection The collection of data was performed between 7:00 and 8:00 AM in the morning after admission to hospital and consisted of an assessment of thirst, and the completion of a questionnaire designed to measure HRQoL, and urine sampling. NYHA classification was made in the HF group. The patients were studied before breakfast and before taking any daily medication. Data on sociodemographic characteristics, co-morbid conditions, hospital stay, admission serum sodium, and current drugs for all patients, as well as echocardiography for ejection fraction for the HF group, were retrieved from the hospital medical records. Occasionally patients were also interviewed. 2.4. Assessment of thirst A visual analogue scale (VAS) was used to assess perceived thirst (Holst et al., 2003). This scale is commonly used to estimate pain and quality of life (Flaherty, 1996), and to evaluate thirst in patients with cancer and renal failure (Wirth and Folstein, 1982; Morita et al., 2001). It has also been validated and used to assess thirst in HF patients (Holst et al., 2003). Study participants were asked to mark with a cross on a 100 mm line to grade their thirst from none (0 mm) to constant thirst (100 mm). 2.5. The HRQoL The study was registered by the Euroqol Group, Rotterdam, Netherlands. The patients completed the Euroqol Group protocol which is a standardized tool for describing and assessing healthrelated quality of life in elderly patients (Brooks, 1996). The instrument can be used regardless of the patient’s illness or treatment. It can also be used both in clinical trials and population studies. Euroqol consists of the questionnaire (EQ-5D), the calculated health profile (EQ-5Dindex), and a VAS ruler for rating selfperceived health (EQ-VAS) (EuroQol Group, 2007). EQ-5D includes five health dimensions: mobility; self-care; usual activities; pain; and anxiety. The severity of his/her problems was classified into one of the three categories: no problems, some problems or extreme problems. The scores for the EQ-5Dindex range from 0.624 to 1, where 1 is the best possible health. In EQVAS the patient selects his/her current self-perceived health status on a scale from 0 = worst health to 100 = best possible health (EuroQol Group, 2007). Response, validity, and reliability of the Euroqol have been tested in several different populations (Brooks et al., 1991; Hurst et al., 1997). 2.6. Urine analyses Urine samples were collected to evaluate the hydration status by a standardized visual assessment of the urine color and by measuring the specific gravity. Directly after collection, the sample was placed in a clear test tube and held against a urine color chart with a white background. The chart had 8 numbered colors ranging from pale straw (urine color = 1) to greenish brown (urine color = 8) (Armstrong et al., 1998) in which 3 indicates dehydration (Casa et al., 2000). Every assessment of color was performed under the same lighting conditions. The highest number was taken if urine color fell between two colors on the chart (Mentes et al., 2006). Urine specific gravity was determined directly after urine color by using the Urisys 1100 (Roche Diagnostics Scandinavia, Bromma, Sweden) along with chemistrip Combur10 Test M urine test. The specific gravity readings obtainable from this analyzer ranged from 1.000
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to 1.030 in 0.005 intervals. Finally, the urine samples were sent to the routine hospital laboratory for the measurement of the potassium and sodium concentrations and of the osmolality. 2.7. NYHA classification The severity of HF was described based on the New York Heart Association classification (NYHA class) which was applied according to the guidelines of the European Society of Cardiology (Dickstein et al., 2008). Patients were asked if they suffered from shortness of breath, fatigue, or palpitations, and if they experienced symptoms during ordinary or less ordinary activity, or at rest. In short, a NYHA class I patient has no symptoms or physical limitations while a NYHA class II patient has slight limitations. NYHA class III implies marked physical limitations. In NYHA class IV, a patient is unable to carry any physical activity without discomfort and has symptoms at rest. NYHA class III was subdivided into IIIa and IIIb, where IIIb described an improved outcome from NYHA class IV, but where the patient was unable to walk 200 m on flat ground without significant physical limitations. 2.8. Statistical analyses A difference in perceived thirst of 20 mm was determined to be clinically interesting. A previous study indicated that the S.D. when a VAS scale is applied on thirst does not exceed 25 mm (Holst et al., 2003). Power analysis then showed that including 50 patients would detect this clinically important difference with a certainty of 80%. Continuous data showing a normal distribution were expressed as the mean S.D. Factors of importance to continuous data were identified by one-, two- or three-way ANOVA or, if data were unbalanced, by multiple regression analysis. The data on perceived thirst were square-root transformed to achieve a normal distribution before being used in these factor analyses. Other data with a skewed distribution, such as the quality of life measures, were expressed as the median (interquartile range) and studied by the Mann–Whitney U-test. The distribution of categorical data (such as urine color and medication) was analyzed by contingency table analysis. A p < 0.05 was considered significant.
3. Results Between February and July 2009, 41 elderly patients with worsening of HF were admitted to the Department of Internal Medicine. Between February and April 2009, 164 patients were admitted to the Department of Geriatrics. Eighteen of the HF and 134 of the control group patients were not asked to participate in the study because they did not meet the inclusion criteria. Only one patient, without HF, declined to participate. Forty-eight patients completed the study, with 23 in the HF group and 25 in the control group. No significant differences between these groups were found with respect to age, gender, length, living alone, or the number of daily medications. However, all the HF patients but only 40% of the controls used diuretics (p < 0.001). The body weight, the number of diagnoses, and the time in hospital also differed between the groups (Table 1). All of the HF patients suffered from shortness of breath and tiredness or fatigue. Fourteen patients (61%) had leg edema and six (26%) reported palpitations. Three patients (13%) had a pacemaker. Fourteen (61%) were classified as NYHA class IIIa, six (26%) as NYHA class IIIb, and three (13%) as NYHA class IV. Thirteen patients in the HF group were examined for ejection fraction in the hospital (mean 32 12%).
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Table 1 Socio-demographic, clinical characteristics analyses of the urine samples and results of the assessment of HRQoL, n, mean S.D., n (%). HF group
Control group
p
23 80.6 6.7 15 (65) 76 12 122 20
25 80.4 8.4 18 (72) 65 19 133 14
NS NS NS <0.02 <0.04
70 10
69 10
NS
15 (63) 52 72 5, 2–6
17 (68) 41 94 13, 9–18
NS <0.03 NS <0.0001
Pharmacotherapy ACE ARB Beta blockers Spironolactone Furosemide Antidepressants Antihistamines Benzodiazepines Opioids Omeprazol
7 (30) 4 (17) 12 (52) 6 (26) 23 (100) 4 (17) 2 (9) 3 (13) 1 (4) 3 (13)
3 (12) 0 (0) 7 (28) 1 (4) 10 (40) 6 (24) 2 (8) 1 (4) 15 (60) 11 (44)
NS NS NS NS <0.0001 NS NS NS <0.0002 <0.04
Co-morbidities Atrial fibrillation Hypertension Angina Myocardial infarction Cardiomyopathy Renal failure Cancer
14 (61) 7 (30) 3 (13) 3 (13) 1 (4) 4 (17) 5 (21)
3 (12) 11 (44) 4 (16) 2 (8) 0 (0) 2 (8) 7 (28)
<0.0003 NS NS NS NS NS NS
2.9 1.2 70 36 32 13 418 131
2.9 1.0 107 51 41 21 527 174
NS <0.006 NS <0.02
1.013 0.005
1.015 0.006
NS
0.50, 0.27–0.72 34, 24–46
0.59, 0.37–0.71 49, 39–54
NS NS
Number of patients Age (years) Women Weight (kg) Systolic blood pressure (mmHg) Diastolic blood pressure (mmHg) Living alone Diagnoses Medications Hospital time (days, median, IQR)
Urine analyses Urine color (shade) Urine sodium (mmol/l) Urine potassium (mmol/l) Urine osmolality (mosmol/kg) Urine specific gravity Quality of life measures EQ-5Dindex EQ-VAS (scale unit)
Notes: NS; not significant, ACE: angiotensin-converting enzyme inhibitor, ARB: angiotensin II receptor blocker.
The main causes of admission for patients in the control group were: musculoskeletal injuries (11 patients, or 44%); infections (6, 24%); brain disorders (3, 12%); tumor (2, 8%); atrial fibrillation (1, 4%); dehydration (1, 4%); and dizziness (1, 4%). The VAS score was much higher for thirst in elderly patients with worsening HF (median 75 mm, interquartile range 56–90) compared with elderly acutely ill patients without HF (median 25 mm, 11–40; p < 0.0001) (Fig. 1). Factors of age, gender, living alone, or taking diuretics were not found to be statistically significant predictors of thirst when analyzed together with the presence or absence of HF (two- or three-way ANOVA and/or multiple linear regression). There was a trend toward more severe thirst for the highest NYHA classes (Fig. 2). The serum sodium concentration on admission was 140.1 3.7 mmol/l in the HF group and 138.7 3.1 mmol/l in the controls (p = 0.15). There were no significant differences between the groups with respect to health-related quality of life (measured by EQ-5Dindex) and self-perceived health (according to EQ-VAS) (Table 1). There was no overall significant linear relationship between these
Fig. 1. Perceived thirst, as expressed by a visual analogue scale (VAS), in 23 patients admitted to hospital for worsening of HF and in 25 other patients admitted to the geriatric department of the same hospital for reasons other than HF. The plot shows the median (central line) and the IQR (box) and 10–90th percentiles (error bars). A difference between the groups was significant by p < 0.0001 (Mann–Whitney Utest).
measures and perceived thirst. However, an exploratory analysis of the HF group showed that the 15 patients with anxiety (according to EQ-5D) graded their thirst higher (median = 85) compared to the other 8 patients (median = 57; p < 0.04). The women had lower EQ-5Dindex values than the men (median = 0.39 and 0.72, respectively; p < 0.03) while a similar difference was not seen among the controls. The urine samples collected from the HF patients had a lower sodium concentration and a lower osmolality than the urine collected from the control patients (Table 1). The urine color chart indicated the presence of dehydration (urine color 3) in 14 patients (61%) in the HF group and in 16 (64%) of the control patients. Perceived thirst did not increase with the presence of darker urine. Instead, there was a tendency toward more severe thirst among those with light urine color (urine color 1–2) in both the HF group (median 80 vs. 65) and in the control group (median 31 vs. 20).
Fig. 2. Perceived thirst, as expressed by a visual analogue scale (VAS), in all individual patients. Those suffering from HF are grouped depending on their NYHA class.
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4. Discussion The results show that elderly patients perceive intensive thirst when admitted to hospital for worsening of HF. Their self-reported thirst score was three times higher than the average for the control group of patients of the same age admitted to hospital for other acute physical diseases. When controlling for the presence of HF, we could not identify statistically any other factor that could call this conclusion into question. The presence of such a remarkable and systematic difference in perceived thirst between the groups was unexpected when the study started. Despite the limited number of studied patients, there even tended to be a direct relationship between the severity of the syndrome and the intensity of the thirst experience (Fig. 2). In the search for confounders it is of interest that not even the daily use of diuretics aggravated perceived thirst. Patients in both groups had a relatively low health-related quality of life and self-perceived health. In a report from Stockholm County, people of the same age without acute illness had about 50% higher scores for life quality than found in the present study (ESH, 2002). However, all of our patients had health problems severe enough for acute admission to hospital. Their quality of life was probably reduced due to a host of factors related to complex and severe disease, such as hip fracture and infection, as well as several symptoms in HF (Blinderman et al., 2008). These health problems probably overshadowed the impact of intense thirst on healthrelated quality of life and self-perceived health. The data on serum sodium, urine sodium and urine osmolality are all consistent with the neurohumoral activation associated with this syndrome, although the marginal rise in serum sodium (1.4 mmol/l) is hardly sufficient to explain the greatly increased thirst among the HF patients. On the other hand, dehydration as evidenced by urine color was as common among the HF patients as in the control group (about 60%). Moreover, urine specific gravity did not differ between the groups. As HF is clearly associated with fluid retention and overhydration, our results show that urine color and specific gravity cannot be used to indicate worsening of HF. So far, urine color has been validated as a simple and practical index of dehydration in sportsmen (Armstrong et al., 1998) but its value in diseased humans remains to be decided. To our knowledge, the present work is the first controlled study to assess thirst in HF patients. The mechanism explaining the marked difference between the two groups is unknown. In healthy humans, thirst is primarily induced by the raised serum osmolality that accompanies dehydration (Sewards and Sewards, 2000). An increased plasma level of angiotensin II is closely linked to the development of HF, but the view that this hormone per se stimulates thirst (Sewards and Sewards, 2000) has recently been challenged by fluid balance experiments in knock-out mice (McKinley et al., 2008). The issue is further complicated by thirst signal impairment in the elderly (Rolls and Phillips, 1990; Stachenfeld et al., 1997; Farrell et al., 2008) that is relevant to the present study as the average age of our patients was 80 years. Current hypotheses that service to explain impairment include reduced cerebral blood flow or changes in higher cortical functioning (Farrell et al., 2008), and attenuated sensitivity of receptors responding to changes in central blood volume (Stachenfeld et al., 1997). Fluid restriction is widely used to combat worsening HF, although studies have shown that this treatment provides unclear clinical benefits in these patients (Travers et al., 2007; Holst et al., 2008). From an ethical perspective, fluid restriction may be questioned as patients with worsening of HF experience severe thirst even before the decision about fluid restriction is made. Peritoneal dialysis has been used in a limited number of HF patients to relieve fluid and osmotic overload, as well as to remove neurohumoral factors that are part of this syndrome (Davies et al.,
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2009; Sa´nchez et al., 2010). We believe that peritoneal dialysis could possibly relieve intense thirst as well. Ions such as sodium would then be replaced by glucose, which, after metabolism into carbon dioxide and water, does not add to the patient’s osmotic burden. This rarely used treatment could be of value for selected patients suffering from debilitating thirst in association with HF. A limitation of the present study is that the ejection fraction was only measured in half of the HF patients and in none of the controls. Moreover, invasive analyses of the neurohumoral factors associated with worsened HF, as well as of the serum osmolality, were not made. Such data could have been used to explore a possible mechanism that, already at this time, could serve to explain the increased thirst. Conclusion Worsening of HF in elderly patients was associated with marked thirst, compared with a group of patients of the same age who were admitted to hospital for other diseases. Health-related quality of life and self-perceived health was low in both groups. Conflict of interest statement None. Acknowledgements We are grateful for the continuous assistance of the medical staff at the Departments of Medicine and Geriatrics at So¨derta¨lje Hospital for collecting the urine samples. We also thank Monica Rydell-Karlsson, RN, Ph.D., at the Sophiahemmet University College, Sweden for valuable support and suggestions concerning this work. References Armstrong, L.E., Soto, J.A., Hacker F.T.Jr., Casa, D.J., Kavouras, S.A., Maresh, C.M., 1998. Urinary indices during dehydration, exercise, and rehydration. Int. J. Sport Nutr. 8, 345–355. Blinderman, C.D., Homel, P., Billings, A., Portenoy, R.K., Tennstedt, S.L., 2008. Symptom distress and quality of life in patients with advanced congestive heart failure. J. Pain Symptom Manage. 35, 594–603. Bra¨nnstro¨m, M., Ekman, I., Norberg, A., Boman, K., Strandberg, G., 2006. Living with severe chronic heart failure in palliative advanced home care. Eur. J. Cardiovasc. Nurs. 5, 295–302. Brooks, R., 1996. EuroQol: the current state of play. Health Policy 37, 53–72. Brooks, R.G., Jendteg, S., Lindgren, B., Persson, U., Bjo¨rk, S., 1991. EuroQol: healthrelated quality of life measurement. Results of the Swedish questionnaire exercise. Health Policy 18, 37–48. Casa, D.J., Armstrong, L.E., Hillman, S.K., Montain, S.J., Reiff, R.V., Rich, B.S., Roberts, W.O., Stone, J.A., 2000. National athletic trainers’ association position statement: fluid replacement for athletes. J. Athl. Train. 35, 212–224. Davies, S., Carlsson, O., Simonsen, O., Johansson, A.C., Venturoli, D., Ledebo, I., Wieslander, A., Chan, C., Rippe, B., 2009. The effects of low-sodium peritoneal dialysis fluids on blood pressure, thirst and volume status. Nephrol. Dial. Transplant. 24, 1609–1617. Dickstein, K., Cohen-Solal, A., Filippatos, G., McMurray, J.J., Ponikowski, P., PooleWilson, P.A., Stro¨mberg, A., van Veldhuisen, D.J., Atar, D., Hoes, A.W., Keren, A., Mebazaa, A., Nieminen, M., Priori, S.G., Swedberg, K., Vahanian, A., Camm, J., De Caterina, R., Dean, V., Funck-Brentano, C., Hellemans, I., Kristensen, S.D., McGregor, K., Sechtem, U., Silber, S., Tendera, M., Widimsky, P., Zamorano, J.L., Auricchio, A., Bax, J., Bo¨hm, M., Corra`, U., della Bella, P., Elliott, P.M., Follath, F., Gheorghiade, M., Hasin, Y., Hernborg, A., Jaarsma, T., Komajda, M., Kornowski, R., Piepoli, M., Prendergast, B., Tavazzi, L., Vachiery, J.L., Verheugt, F.W., Zamorano, J.L., Zannad, F., 2008. ESC guidelines for the diagnosis and treatment of acute and chronic heart failure 2008: the Task Force for the diagnosis and treatment of acute and chronic heart failure 2008 of the European Society of Cardiology. Developed in collaboration with the Heart Failure Association of the ESC (HFA) and endorsed by the European Society of Intensive Care Medicine (ESICM). Eur. J. Heart Fail. 10, 933–989. ESH: Enheten fo¨r socialmedicin och ha¨lsoekonomi, 2002. Geografiska skillnader i ha¨lsorelaterad livskvalitet i Stockholms la¨n 2002. Resultat per kommun och stadsdel, geografisk beredning samt besta¨llaravdelning. Rapport 2006:2. Downloaded 15 June, 2009, from Centrum fo¨r folkha¨lsa, forum fo¨r kunskap och gemensam utveckling. Stockholm County. http://www.folkhalsoguiden.se/ upload/J%c3%a4mlik%20h%c3%a4lsa/GeografNSka%20skillnader%20i%20h%
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Thirst in the elderly with and without heart failure Nana Waldre´us a,*, Fredrik Sjo¨strand b, Robert G. Hahn a,c a
Department of Research, House 10, 3rd Floor, So¨derta¨lje Hospital SE-152 86 So¨derta¨lje, Sweden Department of Clinical Science and Education, Karolinska Institutet, So¨dersjukhuset, SE-118 83 Stockholm, Sweden c Faculty of Health Sciences, Linko¨ping University, SE-581 85 Linko¨ping, Sweden b
A R T I C L E I N F O
A B S T R A C T
Article history: Received 3 June 2010 Received in revised form 27 September 2010 Accepted 28 September 2010 Available online 28 October 2010
Elderly patients with heart failure (HF) may be troubled by thirst, despite the fact that elderly have an impaired ability to sense thirst. The present study was undertaken to compare the intensity of thirst in patients with and without HF and to evaluate how this symptom relates to the health-related quality of life and indices of the fluid balance. Forty-eight patients (mean age 80 years) admitted to hospital with worsening HF (n = 23) or with other acute illness (n = 25) graded their thirst and estimated their healthrelated quality of life (HRQoL). Serum sodium was measured and urine samples were assessed for color and electrolyte content. The HF patients reported significantly more intensive thirst (median = 75 mm) compared with those in the control group (median = 25 mm; p < 0.0001). There was no statistically significant relationship between thirst and HRQoL, which was low overall. Serum sodium and urine color did not differ significantly between the groups, but the urine of the HF patients had a lower sodium concentration and osmolality. We conclude that elderly patients with worsening HF have considerably increased thirst and, hence, intense thirst should be regarded as a symptom of HF. ß 2010 Elsevier Ireland Ltd. All rights reserved.
Keywords: Thirst of elderly Aged heart failure patients Quality of life Dehydration
1. Introduction HF is a progressive, complex clinical syndrome featured by gradual development of symptoms like dyspnoe, fatigue and peripheral edema. The overall prevalence of HF is increasing not only because of aging of the population but also because of successful treatment of cardiovascular diseases (Dickstein et al., 2008). Structural and/or functional cardiac disorders that impair systolic and/or diastolic ventricular function lead to inability of the heart to pump blood with normal filling pressures. This elicits a hormonal cascade which acts to retain sodium and water in the body (So¨derberg et al., 2001; Sergi et al., 2004) although experience holds that many of these patients still complain of excessive thirst (Nordgren and So¨rensen, 2003; Bra¨nnstro¨m et al., 2006; Falk et al., 2007; Holst et al., 2008). This symptom may also seem paradoxical considering that the ability to sense thirst is impaired in the elderly (Rolls and Phillips, 1990; Stachenfeld et al., 1997; Farrell et al., 2008). The relationship between fluid balance and thirst is well studied in young and healthy individuals (Sewards and Sewards, 2000), but rarely in the elderly. Moreover, it is essentially unknown if frequent events with excessive thirst affect the QoL. The purpose of the present study was to compare the intensity of the thirst experience in a group of elderly patients admitted to
* Corresponding author. Tel.: +46 76 774 5199; fax: +46 8 5502 4375. E-mail address: [email protected] (N. Waldre´us). 0167-4943/$ – see front matter ß 2010 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.archger.2010.10.003
hospital due to aggravated HF with those admitted to the same hospital due to other diseases. We also evaluated how thirst affects the HRQoL, and if worsening of HF can be indicated by a urine color chart (Armstrong et al., 1998). 2. Subjects and methods 2.1. Design and setting This open controlled study was performed at the Departments of Internal Medicine and Geriatrics at a middle-sized hospital in the county of Stockholm, Sweden. The local Ethics Committee of Stockholm had approved the study, which complied with the Declaration of Helsinki, and each patient gave his/her informed consent for participation. 2.2. Study cohort Forty-eight patients (65 years of age) were consecutively enrolled and arranged into two groups, depending on the presence of HF. Patients with diabetes or in the end of life with symptom relieving treatment alone were excluded. In the HF group, the patients had just been admitted to hospital due to the worsening of previously known HF, which was their main diagnosis. All patients in the control group had been admitted to the Department of Geriatrics to receive treatment for acute illness, but none of them had been diagnosed with HF.
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2.3. Data collection The collection of data was performed between 7:00 and 8:00 AM in the morning after admission to hospital and consisted of an assessment of thirst, and the completion of a questionnaire designed to measure HRQoL, and urine sampling. NYHA classification was made in the HF group. The patients were studied before breakfast and before taking any daily medication. Data on sociodemographic characteristics, co-morbid conditions, hospital stay, admission serum sodium, and current drugs for all patients, as well as echocardiography for ejection fraction for the HF group, were retrieved from the hospital medical records. Occasionally patients were also interviewed. 2.4. Assessment of thirst A visual analogue scale (VAS) was used to assess perceived thirst (Holst et al., 2003). This scale is commonly used to estimate pain and quality of life (Flaherty, 1996), and to evaluate thirst in patients with cancer and renal failure (Wirth and Folstein, 1982; Morita et al., 2001). It has also been validated and used to assess thirst in HF patients (Holst et al., 2003). Study participants were asked to mark with a cross on a 100 mm line to grade their thirst from none (0 mm) to constant thirst (100 mm). 2.5. The HRQoL The study was registered by the Euroqol Group, Rotterdam, Netherlands. The patients completed the Euroqol Group protocol which is a standardized tool for describing and assessing healthrelated quality of life in elderly patients (Brooks, 1996). The instrument can be used regardless of the patient’s illness or treatment. It can also be used both in clinical trials and population studies. Euroqol consists of the questionnaire (EQ-5D), the calculated health profile (EQ-5Dindex), and a VAS ruler for rating selfperceived health (EQ-VAS) (EuroQol Group, 2007). EQ-5D includes five health dimensions: mobility; self-care; usual activities; pain; and anxiety. The severity of his/her problems was classified into one of the three categories: no problems, some problems or extreme problems. The scores for the EQ-5Dindex range from 0.624 to 1, where 1 is the best possible health. In EQVAS the patient selects his/her current self-perceived health status on a scale from 0 = worst health to 100 = best possible health (EuroQol Group, 2007). Response, validity, and reliability of the Euroqol have been tested in several different populations (Brooks et al., 1991; Hurst et al., 1997). 2.6. Urine analyses Urine samples were collected to evaluate the hydration status by a standardized visual assessment of the urine color and by measuring the specific gravity. Directly after collection, the sample was placed in a clear test tube and held against a urine color chart with a white background. The chart had 8 numbered colors ranging from pale straw (urine color = 1) to greenish brown (urine color = 8) (Armstrong et al., 1998) in which 3 indicates dehydration (Casa et al., 2000). Every assessment of color was performed under the same lighting conditions. The highest number was taken if urine color fell between two colors on the chart (Mentes et al., 2006). Urine specific gravity was determined directly after urine color by using the Urisys 1100 (Roche Diagnostics Scandinavia, Bromma, Sweden) along with chemistrip Combur10 Test M urine test. The specific gravity readings obtainable from this analyzer ranged from 1.000
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to 1.030 in 0.005 intervals. Finally, the urine samples were sent to the routine hospital laboratory for the measurement of the potassium and sodium concentrations and of the osmolality. 2.7. NYHA classification The severity of HF was described based on the New York Heart Association classification (NYHA class) which was applied according to the guidelines of the European Society of Cardiology (Dickstein et al., 2008). Patients were asked if they suffered from shortness of breath, fatigue, or palpitations, and if they experienced symptoms during ordinary or less ordinary activity, or at rest. In short, a NYHA class I patient has no symptoms or physical limitations while a NYHA class II patient has slight limitations. NYHA class III implies marked physical limitations. In NYHA class IV, a patient is unable to carry any physical activity without discomfort and has symptoms at rest. NYHA class III was subdivided into IIIa and IIIb, where IIIb described an improved outcome from NYHA class IV, but where the patient was unable to walk 200 m on flat ground without significant physical limitations. 2.8. Statistical analyses A difference in perceived thirst of 20 mm was determined to be clinically interesting. A previous study indicated that the S.D. when a VAS scale is applied on thirst does not exceed 25 mm (Holst et al., 2003). Power analysis then showed that including 50 patients would detect this clinically important difference with a certainty of 80%. Continuous data showing a normal distribution were expressed as the mean S.D. Factors of importance to continuous data were identified by one-, two- or three-way ANOVA or, if data were unbalanced, by multiple regression analysis. The data on perceived thirst were square-root transformed to achieve a normal distribution before being used in these factor analyses. Other data with a skewed distribution, such as the quality of life measures, were expressed as the median (interquartile range) and studied by the Mann–Whitney U-test. The distribution of categorical data (such as urine color and medication) was analyzed by contingency table analysis. A p < 0.05 was considered significant.
3. Results Between February and July 2009, 41 elderly patients with worsening of HF were admitted to the Department of Internal Medicine. Between February and April 2009, 164 patients were admitted to the Department of Geriatrics. Eighteen of the HF and 134 of the control group patients were not asked to participate in the study because they did not meet the inclusion criteria. Only one patient, without HF, declined to participate. Forty-eight patients completed the study, with 23 in the HF group and 25 in the control group. No significant differences between these groups were found with respect to age, gender, length, living alone, or the number of daily medications. However, all the HF patients but only 40% of the controls used diuretics (p < 0.001). The body weight, the number of diagnoses, and the time in hospital also differed between the groups (Table 1). All of the HF patients suffered from shortness of breath and tiredness or fatigue. Fourteen patients (61%) had leg edema and six (26%) reported palpitations. Three patients (13%) had a pacemaker. Fourteen (61%) were classified as NYHA class IIIa, six (26%) as NYHA class IIIb, and three (13%) as NYHA class IV. Thirteen patients in the HF group were examined for ejection fraction in the hospital (mean 32 12%).
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Table 1 Socio-demographic, clinical characteristics analyses of the urine samples and results of the assessment of HRQoL, n, mean S.D., n (%). HF group
Control group
p
23 80.6 6.7 15 (65) 76 12 122 20
25 80.4 8.4 18 (72) 65 19 133 14
NS NS NS <0.02 <0.04
70 10
69 10
NS
15 (63) 52 72 5, 2–6
17 (68) 41 94 13, 9–18
NS <0.03 NS <0.0001
Pharmacotherapy ACE ARB Beta blockers Spironolactone Furosemide Antidepressants Antihistamines Benzodiazepines Opioids Omeprazol
7 (30) 4 (17) 12 (52) 6 (26) 23 (100) 4 (17) 2 (9) 3 (13) 1 (4) 3 (13)
3 (12) 0 (0) 7 (28) 1 (4) 10 (40) 6 (24) 2 (8) 1 (4) 15 (60) 11 (44)
NS NS NS NS <0.0001 NS NS NS <0.0002 <0.04
Co-morbidities Atrial fibrillation Hypertension Angina Myocardial infarction Cardiomyopathy Renal failure Cancer
14 (61) 7 (30) 3 (13) 3 (13) 1 (4) 4 (17) 5 (21)
3 (12) 11 (44) 4 (16) 2 (8) 0 (0) 2 (8) 7 (28)
<0.0003 NS NS NS NS NS NS
2.9 1.2 70 36 32 13 418 131
2.9 1.0 107 51 41 21 527 174
NS <0.006 NS <0.02
1.013 0.005
1.015 0.006
NS
0.50, 0.27–0.72 34, 24–46
0.59, 0.37–0.71 49, 39–54
NS NS
Number of patients Age (years) Women Weight (kg) Systolic blood pressure (mmHg) Diastolic blood pressure (mmHg) Living alone Diagnoses Medications Hospital time (days, median, IQR)
Urine analyses Urine color (shade) Urine sodium (mmol/l) Urine potassium (mmol/l) Urine osmolality (mosmol/kg) Urine specific gravity Quality of life measures EQ-5Dindex EQ-VAS (scale unit)
Notes: NS; not significant, ACE: angiotensin-converting enzyme inhibitor, ARB: angiotensin II receptor blocker.
The main causes of admission for patients in the control group were: musculoskeletal injuries (11 patients, or 44%); infections (6, 24%); brain disorders (3, 12%); tumor (2, 8%); atrial fibrillation (1, 4%); dehydration (1, 4%); and dizziness (1, 4%). The VAS score was much higher for thirst in elderly patients with worsening HF (median 75 mm, interquartile range 56–90) compared with elderly acutely ill patients without HF (median 25 mm, 11–40; p < 0.0001) (Fig. 1). Factors of age, gender, living alone, or taking diuretics were not found to be statistically significant predictors of thirst when analyzed together with the presence or absence of HF (two- or three-way ANOVA and/or multiple linear regression). There was a trend toward more severe thirst for the highest NYHA classes (Fig. 2). The serum sodium concentration on admission was 140.1 3.7 mmol/l in the HF group and 138.7 3.1 mmol/l in the controls (p = 0.15). There were no significant differences between the groups with respect to health-related quality of life (measured by EQ-5Dindex) and self-perceived health (according to EQ-VAS) (Table 1). There was no overall significant linear relationship between these
Fig. 1. Perceived thirst, as expressed by a visual analogue scale (VAS), in 23 patients admitted to hospital for worsening of HF and in 25 other patients admitted to the geriatric department of the same hospital for reasons other than HF. The plot shows the median (central line) and the IQR (box) and 10–90th percentiles (error bars). A difference between the groups was significant by p < 0.0001 (Mann–Whitney Utest).
measures and perceived thirst. However, an exploratory analysis of the HF group showed that the 15 patients with anxiety (according to EQ-5D) graded their thirst higher (median = 85) compared to the other 8 patients (median = 57; p < 0.04). The women had lower EQ-5Dindex values than the men (median = 0.39 and 0.72, respectively; p < 0.03) while a similar difference was not seen among the controls. The urine samples collected from the HF patients had a lower sodium concentration and a lower osmolality than the urine collected from the control patients (Table 1). The urine color chart indicated the presence of dehydration (urine color 3) in 14 patients (61%) in the HF group and in 16 (64%) of the control patients. Perceived thirst did not increase with the presence of darker urine. Instead, there was a tendency toward more severe thirst among those with light urine color (urine color 1–2) in both the HF group (median 80 vs. 65) and in the control group (median 31 vs. 20).
Fig. 2. Perceived thirst, as expressed by a visual analogue scale (VAS), in all individual patients. Those suffering from HF are grouped depending on their NYHA class.
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4. Discussion The results show that elderly patients perceive intensive thirst when admitted to hospital for worsening of HF. Their self-reported thirst score was three times higher than the average for the control group of patients of the same age admitted to hospital for other acute physical diseases. When controlling for the presence of HF, we could not identify statistically any other factor that could call this conclusion into question. The presence of such a remarkable and systematic difference in perceived thirst between the groups was unexpected when the study started. Despite the limited number of studied patients, there even tended to be a direct relationship between the severity of the syndrome and the intensity of the thirst experience (Fig. 2). In the search for confounders it is of interest that not even the daily use of diuretics aggravated perceived thirst. Patients in both groups had a relatively low health-related quality of life and self-perceived health. In a report from Stockholm County, people of the same age without acute illness had about 50% higher scores for life quality than found in the present study (ESH, 2002). However, all of our patients had health problems severe enough for acute admission to hospital. Their quality of life was probably reduced due to a host of factors related to complex and severe disease, such as hip fracture and infection, as well as several symptoms in HF (Blinderman et al., 2008). These health problems probably overshadowed the impact of intense thirst on healthrelated quality of life and self-perceived health. The data on serum sodium, urine sodium and urine osmolality are all consistent with the neurohumoral activation associated with this syndrome, although the marginal rise in serum sodium (1.4 mmol/l) is hardly sufficient to explain the greatly increased thirst among the HF patients. On the other hand, dehydration as evidenced by urine color was as common among the HF patients as in the control group (about 60%). Moreover, urine specific gravity did not differ between the groups. As HF is clearly associated with fluid retention and overhydration, our results show that urine color and specific gravity cannot be used to indicate worsening of HF. So far, urine color has been validated as a simple and practical index of dehydration in sportsmen (Armstrong et al., 1998) but its value in diseased humans remains to be decided. To our knowledge, the present work is the first controlled study to assess thirst in HF patients. The mechanism explaining the marked difference between the two groups is unknown. In healthy humans, thirst is primarily induced by the raised serum osmolality that accompanies dehydration (Sewards and Sewards, 2000). An increased plasma level of angiotensin II is closely linked to the development of HF, but the view that this hormone per se stimulates thirst (Sewards and Sewards, 2000) has recently been challenged by fluid balance experiments in knock-out mice (McKinley et al., 2008). The issue is further complicated by thirst signal impairment in the elderly (Rolls and Phillips, 1990; Stachenfeld et al., 1997; Farrell et al., 2008) that is relevant to the present study as the average age of our patients was 80 years. Current hypotheses that service to explain impairment include reduced cerebral blood flow or changes in higher cortical functioning (Farrell et al., 2008), and attenuated sensitivity of receptors responding to changes in central blood volume (Stachenfeld et al., 1997). Fluid restriction is widely used to combat worsening HF, although studies have shown that this treatment provides unclear clinical benefits in these patients (Travers et al., 2007; Holst et al., 2008). From an ethical perspective, fluid restriction may be questioned as patients with worsening of HF experience severe thirst even before the decision about fluid restriction is made. Peritoneal dialysis has been used in a limited number of HF patients to relieve fluid and osmotic overload, as well as to remove neurohumoral factors that are part of this syndrome (Davies et al.,
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2009; Sa´nchez et al., 2010). We believe that peritoneal dialysis could possibly relieve intense thirst as well. Ions such as sodium would then be replaced by glucose, which, after metabolism into carbon dioxide and water, does not add to the patient’s osmotic burden. This rarely used treatment could be of value for selected patients suffering from debilitating thirst in association with HF. A limitation of the present study is that the ejection fraction was only measured in half of the HF patients and in none of the controls. Moreover, invasive analyses of the neurohumoral factors associated with worsened HF, as well as of the serum osmolality, were not made. Such data could have been used to explore a possible mechanism that, already at this time, could serve to explain the increased thirst. Conclusion Worsening of HF in elderly patients was associated with marked thirst, compared with a group of patients of the same age who were admitted to hospital for other diseases. Health-related quality of life and self-perceived health was low in both groups. Conflict of interest statement None. Acknowledgements We are grateful for the continuous assistance of the medical staff at the Departments of Medicine and Geriatrics at So¨derta¨lje Hospital for collecting the urine samples. We also thank Monica Rydell-Karlsson, RN, Ph.D., at the Sophiahemmet University College, Sweden for valuable support and suggestions concerning this work. References Armstrong, L.E., Soto, J.A., Hacker F.T.Jr., Casa, D.J., Kavouras, S.A., Maresh, C.M., 1998. Urinary indices during dehydration, exercise, and rehydration. Int. J. Sport Nutr. 8, 345–355. Blinderman, C.D., Homel, P., Billings, A., Portenoy, R.K., Tennstedt, S.L., 2008. Symptom distress and quality of life in patients with advanced congestive heart failure. J. Pain Symptom Manage. 35, 594–603. Bra¨nnstro¨m, M., Ekman, I., Norberg, A., Boman, K., Strandberg, G., 2006. Living with severe chronic heart failure in palliative advanced home care. Eur. J. Cardiovasc. Nurs. 5, 295–302. Brooks, R., 1996. EuroQol: the current state of play. Health Policy 37, 53–72. Brooks, R.G., Jendteg, S., Lindgren, B., Persson, U., Bjo¨rk, S., 1991. EuroQol: healthrelated quality of life measurement. Results of the Swedish questionnaire exercise. Health Policy 18, 37–48. Casa, D.J., Armstrong, L.E., Hillman, S.K., Montain, S.J., Reiff, R.V., Rich, B.S., Roberts, W.O., Stone, J.A., 2000. National athletic trainers’ association position statement: fluid replacement for athletes. J. Athl. Train. 35, 212–224. Davies, S., Carlsson, O., Simonsen, O., Johansson, A.C., Venturoli, D., Ledebo, I., Wieslander, A., Chan, C., Rippe, B., 2009. The effects of low-sodium peritoneal dialysis fluids on blood pressure, thirst and volume status. Nephrol. Dial. Transplant. 24, 1609–1617. Dickstein, K., Cohen-Solal, A., Filippatos, G., McMurray, J.J., Ponikowski, P., PooleWilson, P.A., Stro¨mberg, A., van Veldhuisen, D.J., Atar, D., Hoes, A.W., Keren, A., Mebazaa, A., Nieminen, M., Priori, S.G., Swedberg, K., Vahanian, A., Camm, J., De Caterina, R., Dean, V., Funck-Brentano, C., Hellemans, I., Kristensen, S.D., McGregor, K., Sechtem, U., Silber, S., Tendera, M., Widimsky, P., Zamorano, J.L., Auricchio, A., Bax, J., Bo¨hm, M., Corra`, U., della Bella, P., Elliott, P.M., Follath, F., Gheorghiade, M., Hasin, Y., Hernborg, A., Jaarsma, T., Komajda, M., Kornowski, R., Piepoli, M., Prendergast, B., Tavazzi, L., Vachiery, J.L., Verheugt, F.W., Zamorano, J.L., Zannad, F., 2008. ESC guidelines for the diagnosis and treatment of acute and chronic heart failure 2008: the Task Force for the diagnosis and treatment of acute and chronic heart failure 2008 of the European Society of Cardiology. Developed in collaboration with the Heart Failure Association of the ESC (HFA) and endorsed by the European Society of Intensive Care Medicine (ESICM). Eur. J. Heart Fail. 10, 933–989. ESH: Enheten fo¨r socialmedicin och ha¨lsoekonomi, 2002. Geografiska skillnader i ha¨lsorelaterad livskvalitet i Stockholms la¨n 2002. Resultat per kommun och stadsdel, geografisk beredning samt besta¨llaravdelning. Rapport 2006:2. Downloaded 15 June, 2009, from Centrum fo¨r folkha¨lsa, forum fo¨r kunskap och gemensam utveckling. Stockholm County. http://www.folkhalsoguiden.se/ upload/J%c3%a4mlik%20h%c3%a4lsa/GeografNSka%20skillnader%20i%20h%
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