***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: A study of prognosis over the first six weeks following admission to a department of geriatric medicine compared the predictive value of a clinical assessment at admission with other more objective parameters such as profile investigations , mental test score and assessment of dehydration and constitutional upset .  A total of 739 patients were studied prospect ively . The  clinical assessment  proved to be by far the strongest predictor of six-week mortality . In men the prediction it gave was not improved significantly by addition of the other factors . In women serum albumin , blood urea and assessment of constitutional upset added significantly to the prediction , thought the overall improvement in classification was small and mental test score made a borderline contribution only Background and Purpose Abnormal physiological parameters after acute stroke may induce early neurological deterioration . Studies of the effect of dehydration on stroke outcome are limited . We examined the association of raised plasma osmolality on stroke outcome at 3 months and the change of plasma osmolality with hydration during the first week after stroke . Methods Acute stroke patients had their plasma osmolality measured at admission and at days 1 , 3 , and 7 . Maximum plasma osmolality and the area under curve ( AUC ) were also calculated during the first week . Patients were stratified according to how they were hydrated : orally , intravenously , or both . Outcome included survival at 3 months after stroke . Logistic regression was performed to examine the association between raised plasma osmolality ( > 296 mOsm/kg ) and survival , adjusting for stroke severity . Linear regression was performed to examine the pattern of plasma osmolality across hydration groups . Results One hundred sixty-seven patients were included . Mean admission ( 300 mOsm/kg , SD 11.4 ) , maximum ( 308.1 mOsm/kg , SD 17.1 ) , and AUC ( 298.3 mOsm/kg , SD 11.7 ) plasma osmolality were significantly higher in those who died compared with survivors ( 293.1 mOsm/kg [ SD 8.2 ] , 297.7 mOsm/kg [ SD 8.7 ] , and 291.7 mOsm/kg [ SD 8.1 ] , respectively;P < 0.0001 ) . Admission plasma osmolality > 296 mOsm/kg was significantly associated with mortality ( OR 2.4 , 95 % CI 1.0 to 5.9 ) . In patients hydrated intravenously , there was no significant fall in plasma osmolality compared with patients hydrated orally ( P = 0.68 ) . Conclusions Raised plasma osmolality on admission is associated with stroke mortality , after correcting for case mix . Correction of dehydration after stroke requires a more systematic approach . Trials are required to determine whether correcting dehydration after stroke improves outcome OBJECTIVES Multi-Frequency Bioelectrical Impedance Analysis ( MFBIA ) is a quick , simple , and inexpensive method to assess body fluid compartments . This study aim ed at determining the validity of MFBIA in detecting clinical ly relevant changes of fluid balance in geriatric patients . DESIGN A prospect i ve , observational study . SETTING The 22-bed Geriatric Department of the University Hospital Nijmegen . PARTICIPANTS Hospitalized patients were eligible if they did not have a pacemaker , were not suffering from terminal illnesses , and did not have psychogeriatric diseases likely to interfere with capacity to consent or comply . During a 16-months period , 218 patients were admitted , of whom 78 patients were eligible and 53 consented to participate . MEASUREMENTS Each subject 's fluid balance was diagnosed twice a week as dehydrated , overhydrated , or euvolemic , based on st and ardized physical examination , laboratory tests , and weight evaluation . Changes in fluid balance were quantified by measuring total body water ( TBW ) and extracellular fluid ( ECF ) applying deuterium- and bromide-dilution techniques . Impedance at 1 , 5 , 50 , and 100 kHz and body weight were measured daily . Sensitivity and Guyatt 's responsiveness indexes of MFBIA in detecting dehydration and overhydration were determined . RESULTS In total , 1071 MFBIA measurements were performed , during which 14 transitions from dehydration to euvolemia and 13 transitions from overhydration to euvolemia were monitored . Rehydration of dehydrated patients caused an increase in TBW and ECF of 3.4 + /- 1.8 L and 1.9 + /- 1.9 L , respectively , which result ed in significant decreases in impedance of 133 + /- 67 omega at 1 kHz and 93 + /- 61 omega at 100 kHz ( P = .001 ) . Treatment of overhydrated patients caused a TBW and ECF loss of 3.8 + /- 4.2 L and 3.1 + /- 3.8 L , respectively , which result ed in significant increases in impedance of 104 + /- 72 omega at 1 kHz and 81 + /- 68 omega at 100 kHz ( P < .001 ) . Sensitivity of a single MFBIA in diagnosing dehydration and overhydration was 14 % and 17 % , respectively . Responsiveness indexes of weighing and MFBIA for dehydration and overhydration were similar at all frequencies and greater than one . CONCLUSION The sensitivity of a single impedance measurement in detecting dehydration and overhydration was low . However , responsiveness of serial measurements to intra-individual changes in fluid balance was good . Therefore , this noninvasive technique may be used in clinical practice to improve monitoring fluid balance in geriatric patients , especially when daily weighing is difficult Whole blood viscosity , plasma viscosity , hematocrit , and fibrinogen are considered independent risk factors for coronary heart disease and can be elevated by dehydration . The associations between fatal coronary heart disease and intake of water and fluids other than water were examined among the 8,280 male and 12,017 female participants aged 38 - 100 years who were without heart disease , stroke , or diabetes at baseline in 1976 in the Adventist Health Study , a prospect i ve cohort study . A total of 246 fatal coronary heart disease events  occurred during the 6-year follow-up . High daily intakes of water ( five or more glasses ) compared with low ( two or fewer glasses ) were associated with a relative risk in men of 0.46 ( 95 % confidence interval ( CI ) : 0.28 , 0.75 ; p trend = 0.001 ) and , in women , of 0.59 ( 95 % CI : 0.36 , 0.97 ) . A high versus low intake of fluids other than water was associated with a relative risk of 2.47 ( 95 % CI : 1.04 , 5.88 ) in women and of 1.46 ( 95 % CI : 0.7 , 3.03 ) in men . All associations remained virtually unchanged in multivariate analysis adjusting for age , smoking , hypertension , body mass index , education , and ( in women only ) hormone replacement therapy . Fluid intake as a putative coronary heart disease risk factor may deserve further consideration in other population s or using other study design BACKGROUND Bedside ultrasound has been suggested as a non-invasive modality to estimate central venous pressure ( CVP ) . OBJECTIVE Evaluate a simple bedside ultrasound technique to measure the diameter of the inferior vena cava ( IVC ) and correlate to simultaneously measured CVP . Secondary comparisons include anatomic location , probe orientation , and phase of respiration . METHODS An unblinded prospect i ve observation study was performed in an emergency department and critical care unit . Subjects were a convenience sample of adult patients with a central line at the superior venocaval-atrial junction .  Ultrasound measured transverse and longitudinal diameters of the IVC at the subxiphoid , suprailiac , and mid-abdomen , each measured at end-inspiration and end-expiration . Correlation and regression analysis were used to relate CVP and IVC diameters . RESULTS There were 72 subjects with a mean age of 67 years ( range 21 - 94 years ) , 37 ( 53 % ) male , enrolled over 9 months . Seven subjects were excluded for tricuspid valvulopathy . Primary diagnoses were : respiratory failure 12 ( 18 % ) , sepsis 11 ( 17 % ) , and pancreatitis 3 ( 5 % ) . There were 28 ( 43 % ) patients mechanically ventilated . Adequate measurements were obtainable in 57 ( 89 % ) using the subxiphoid , in 44 ( 68 % ) using the mid-abdomen , and in 28 ( 43 % ) using the suprailiac views . The correlation coefficients were statistically significant at 0.49 ( 95 % confidence interval [ CI ] 0.26 - 0.66 ) , 0.51 ( 95 % CI 0.23 - 0.71 ) , and 0.50 ( 95 % CI 0.14 - 0.74 ) for end-inspiratory longitudinal subxiphoid , midpoint , and suprailiac views , respectively . Transverse values were statistically significant at 0.42 ( 95 % CI 0.18 - 0.61 ) , 0.38 ( 95 % CI 0.09 - 0.61 ) , and 0.67 ( 95 % CI 0.40 - 0.84 ) , respectively . End-expiratory measurements gave similar or slightly less significant values . CONCLUSION The subxiphoid was the most reliably viewed of the three anatomic locations ; however , the suprailiac view produced superior correlations to the CVP . Longitudinal views generally outperformed transverse views . A simple ultrasound measure of the IVC yields weak correlation to the CVP AIM Investigation was done in the institutionalized elderly in order to know the value of urine osmolality in this population . METHODS Cross sectional study was done in the government institutionalized elderly that localized in South Jakarta . By using simple r and om sampling , 50 elderly people were chosen from all of the residents in this institutionalized elderly aged more than 60 years . They were excluded if they had diabetes mellitus , abnormal cortisol ( reference range of morning cortisol , 5 - 25 ug/dL ) , potassium less than 3 meq/L , chronic diarrhoe , congestive heart failure , nephrotic syndrome , and cirrhosis of the liver , and also if they were in manitol or diuretic treatment , and not cooperative . All of these data were analyzed with descriptive analysis and comparative T-test of two non-related groups . RESULTS There were 28 elderly peoples consisted of 13 males and 15 females participated in this study . The mean of the urine osmolality was 581 + /- 174 mosmol/Kg . The mean of the urine osmolality in the female group ( 657.33 + /- 126.54 mosmol/kg ) was significantly higher than in the male group ( p = 0.01 ) . CONCLUSION The urine osmolality in the elderly is high and the so-called normal value is 407 - 755 mosmol/Kg . Further study is needed to investigate the lowest urine osmolality value as the diagnostic tool of hyponatremia due to water excretion disorder in the elderly BACKGROUND Well-recognized markers for static ( one time ) or dynamic ( monitoring over time ) dehydration assessment have not been rigorously tested for their usefulness in clinical , military , and sports medicine communities . OBJECTIVE This study evaluated the components of biological variation and the accuracy of potential markers in plasma , urine , saliva , and body mass ( B(m ) ) for static and dynamic dehydration assessment . DESIGN We studied 18 healthy volunteers ( 13 men and 5 women ) while carefully controlling hydration and numerous preanalytic factors . Biological variation was determined over 3 consecutive days by using published methods . Atypical values based on statistical deviations from a homeostatic set point were examined . Measured deviations in body fluid were produced by using a separate , prospect i ve dehydration experiment and evaluated by receiver operating characteristic ( ROC ) analysis to quantify diagnostic accuracy . RESULTS All dehydration markers displayed substantial individuality and one-half of the dehydration markers displayed marked heterogeneity of intraindividual variation . Decision levels for all dehydration markers were within one SD of the ROC criterion values , and most levels were nearly identical to the prospect i ve group means after volunteers were dehydrated by 1.8 - 7.0 % of B(m ) . However , only plasma osmolality ( P(osm ) ) showed statistical promise for use in the static dehydration assessment . A diagnostic decision level of 301 plusmn 5 mmol/kg was proposed . Reference change values of 9 mmol/kg ( P(osm ) ) , 0.010 [ urine specific gravity ( U(sg ) ) ] , and 2.5 % change in B(m ) were also statistically valid for dynamic dehydration assessment at the 95 % probability level . CONCLUSIONS P(osm ) is the only useful marker for static dehydration assessment . P(osm ) , U(sg ) , and B(m ) are valid markers in the setting of dynamic dehydration assessment BACKGROUND Older adults 
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No test was consistently useful in more than one study .Combining two tests so that an individual both missed some drinks between meals and expressed fatigue was sensitive at 0.71 ( 95 % CI 0.29 to 0.96 ) and specific at 0.92 ( 95 % CI 0.83 to 0.97).There was sufficient evidence to suggest that several st and -alone tests often used to assess dehydration in older people ( including fluid intake , urine specific gravity , urine colour , urine volume , heart rate , dry mouth , feeling thirsty and BIA assessment of intracellular water or extracellular water ) are not useful , and should not be relied on individually as ways of assessing presence or absence of dehydration in older people .
No tests were found consistently useful in diagnosing current water-loss dehydration .
AUTHORS ' CONCLUSIONS There is limited evidence of the diagnostic utility of any individual clinical symptom , sign or test or combination of tests to indicate water-loss dehydration in older people .
Individual tests should not be used in this population to indicate dehydration ; they miss a high proportion of people with dehydration , and wrongly label those who are adequately hydrated .
Combining several tests may improve diagnostic accuracy