Hyponatremia in Geriatric Inhospital Patients: Effects on Results of a Comprehensive Geriatric Assessment

Abstract

Objectives: To study whether geriatric patients with mild-to-moderate hyponatremia (≤131 mmol/l) reveal different outcomes in structured tests for functional and cognitive impairments, depression and malnutrition compared to normonatremic patients. Design: Single-center, retrospective case control study. Setting: The study was conducted in a Geriatric Evaluation and Management Unit of a Department for Geriatrics and Internal Medicine. Methods and Participants: We included 2,880 elderly patients (75.6% female, mean age 78.6 ± 6.98 years), consecutively admitted to the GEMU primarily or from another hospital or emergency department. Results were compared between a group of 129 patients with mild-to-moderate hyponatremia (118–131 mmol/l) and an age- and sex-matched control group of 129 patients with normal serum sodium values (>135 mmol/l). To assess functional and cognitive status, depression and malnutrition we used standardized tests of a geriatric assessment. Results: 16.7% (n = 477) of the total 2,880 patients were hyponatremic (≤135 mmol/l), 4.5% (n = 129) revealed moderate hyponatremia. Compared to the control group, these patients had significantly worse results in all tests of the Geriatric Assessment, including Activities of Daily Living, Mini Mental State Examination, Clock Completion Test, Geriatric Depression Score, Tinetti Mobility Test and the Timed Up&Go Test and the Mini Nutritional Assessment. Comorbidities were assessed by the Charlson Comorbidity Index and the Cumulative Illness Rating Scale with no significant difference between the two groups. The hyponatremic patients received significantly more medications than the normonatremic control group, but we could not find a significant difference with respect to the use of a distinct single drug therapy. Conclusion: We were able to demonstrate that geriatric patients with mild-to-moderate hyponatremia revealed a significantly worse outcome in all standardized tests of the geriatric assessment compared to a normonatremic control group. Serum sodium levels should therefore be considered when interpreting common tests of geriatric assessment.

Prognosis of Hyponatremia in Elderly Patients With Fragility Fractures

“…Consequently, serum sodium measurements were missing in 56% of total patient-days in hospital. This same limitation has previously been encountered by various other groups and confirms concerns that clinical awareness of hyponatremia is low, predisposing already frail patients to worsened clinical outcomes [5, 27, 28]. Since patients did not have daily serum sodium measurements, it is likely that our report may underestimate the true incidence of hyponatremia in EPFF.…”

Hyponatraemia in older patients: a clinical and practical approach

“…Renneboog et al found that patients with mild/moderate chronic 'asymptomatic' hyponatraemia present cognitive impairment upon testing, whereas the same patients with eunatraemia do not. 23 24 Gait instability is frequent in patients with mild/moderate hyponatraemia, and induces falls. In fact, 'asymptomatic' hyponatraemic patients were 67 times more likely to fall than normonatraemic controls in Renneboog's study.…”

“…28 Mild hyponatraemia can induce marked anorexia and hyponatraemic patients on a geriatric ward present significantly lower mini-nutritional assessment scores than matched eunatraemic controls. 24 Non-correction of S Na for TP can also cause the frequency/severity of hyponatraemia to be underestimated. Correct evaluation of nutritional status is therefore essential, as are the detection and treatment of hyponatraemia in the malnourished elderly.…”

Hyponatremia in hospitalised patients with heart failure in internal medicine: Analysis of the Spanish national minimum basic data set (MBDS) (2005–2011)

“…These results underline the fact that hyponatremia with heart failure tends to afflict clinically frail older patients with malnutrition and neurological dysfunction [24][25][26]. Indeed, numerous hospital registries show that hyponatremia is associated to older age, the use of diuretics and an increasing comorbidity with conditions that predispose patients to the onset of this ion abnormality disorder (HF, cirrhosis, nephrotic syndrome, hypothyroidism, etc.)…”

“…This limitation makes it difficult to compare the results obtained with other HF registries. Regarding the type of hyponatremia, we have not been able to obtain variables associated with patients' degree of congestion (dilutional hyponatremia), NYHA functional classes, natriuretic peptide levels or hyponatremia treatment variables (particularly diuretics) [26,18]. The study design also did not allow us to differentiate between patients with HF who acquired hyponatremia during their hospital stay and those who already had chronic hyponatremia before the onset of decompensated heart failure.…”