Osmotic stress and mortality in elderly patients with kidney failure: a retrospective study

• Published in: Clinical interventions in aging Vol. 14; pp. 225 - 229
• Main Authors: Grangeon-Chapon, Caroline, Dodoi, Manuella, Esnault, Vincent Lm, Favre, Guillaume
• Format: Journal Article
• Language: English
• Published: New Zealand Dove Medical Press Limited 01-01-2019; Taylor & Francis Ltd; Dove Medical Press
• Subjects: Acute kidney injury; Acute Kidney Injury - epidemiology; Acute Kidney Injury - mortality; Acute Kidney Injury - physiopathology; Aged; Aged patients; Aged, 80 and over; Aging; Analysis; Azotemia - epidemiology; Bacterial infections; Care and treatment; Chronic kidney failure; Diabetes; Diagnosis; Disability; Female; Health aspects; Hospitals; Humans; Hypernatremia; Hypernatremia - epidemiology; Hyponatremia - epidemiology; Intensive care; Kidney diseases; Male; Mortality; Multivariate analysis; Nephrology; Older people; Original Research; Osmoregulation; Osmoregulation - physiology; Osmotic Pressure - physiology; Patient outcomes; Physiological aspects; Retrospective Studies; Risk Factors; Systematic review; Water balance (Hydrology); Water-electrolyte balance (Physiology); France; osmoregulation; acute kidney injury; aging; chronic kidney failure; hypernatremia
• ISSN: 1178-1998; 1176-9092; 1178-1998
• DOI: 10.2147/CIA.S158987

Water balance disorders are associated with a high risk of death in elderly patients. The role of osmotic stress intensity and its direction toward hypo- or hypernatremia is a matter of controversy regarding patients' survival. The aims of this study were, first, to measure the frequency of cellular hydration disorders in patients over 75 years old hospitalized in nephrology department for reversible acute renal failure, and second, to compare the impact of hyperhydration and hypohydration on the risk of death at 6 months.
We retrospectively studied the data of 279 patients with chronic kidney disease (CKD), aged 75 years or older, with pre-renal azotemia who experienced dysnatremia. We classified them according to natremia levels and compared their outcome in univariate and multivariate analysis.
The patients were on average 83.2±5.4 years old. Among them, 128 were normonatremic, 82 were hyponatremic and 69 were hypernatremic. Osmotic stress intensity appreciated by the variation rate of natremia did not differ significantly between hyper- and hyponatremic patients. Patients had CKD stage 3B and 4 with acute kidney injury (AKI) of different severities. We observed that only hypernatremia was linked to death in the first 6 months following hospital discharge.
Hypernatremia is a strong predictor of fatal outcome in elderly patients suffering from chronic kidney impairment and referred for pre-renal azotemia.