Approach to the Management of Hypernatraemia in Older Hospitalised Patients.

Hypernatraemia is associated with high morbidity and mortality and is more common in patients of older age, nursing home residents and those with cognitive impairment and restricted mobility. The most common cause in hospital settings is water dehydration due to reduced intake although other causes should be identified. Once identified, prompt management is necessary to avoid delayed correction as prolonged hypernatremia is associated with increased hospital stay and mortality. Comprehensive history-taking and physical examination, basic investigations and medication review are essential to identify causative and remediable factors in those admitted with hypernatraemia. Accurate calculation of fluid deficit and ongoing losses is essential in order to ensure adequate fluid replacement, The administration of appropriate, usually hypotonic, fluids is also essential to the timely restoration of eunatraemia. Although evidence of definite harm resulting from rapid correction is lacking, a serum sodium reduction rate of <12 mmol/l day is advised with the caveat that close monitoring of electrolytes is required to ensure the desired correction rate is being achieved. Medical and nursing professionals should have access to a local hospital protocol to guide management of patients with hypernatraemia to improve patient outcomes and mitigate the risk of harm, particularly from under-recognition and slow correction.

A Comparison of Community-Acquired and Hospital-Acquired Hypernatraemia in Patients who are Acutely Admitted to Hospital.

Background Hypernatraemia is associated with a short-term mortality of 20-60%. Age-related physiological changes predispose patients to hypernatraemia. This study reviewed acutely admitted patients comparing those with community-acquired (CAH) and hospital-acquired hypernatraemia (HAH). Methods A retrospective study of 102 consecutive acute medical in-patients with serum [Na]>145 mmol/L was conducted. Baseline characteristics, clinical presentation, laboratory values, monitoring, management and outcomes were compared between CAH and HAH groups. Results Patients were exclusively older (>69 years). Forty patients (39.2%) had CAH and sixty-two (61.8%) had HAH. Those with CAH were more likely to be NH residents, have dementia and reduced mobility. Most HAH patients had mild hypernatraemia initially (75.8%, n=47), and higher rates of acute kidney injury (27% (n=11) vs 8% (n=3)/p=0.02) were observed. Monitoring was inadequate and no patient had a free water deficit documented. Medication review and intravenous fluid prescribing was similar between groups. The median length of stay of discharged HAH patients was longer (22.5 vs 8 days/p=0.005). Mortality rates were similar (47% (n=29) vs 37% (n=15)/p=0.416). Time from admission to death was higher in HAH patients (16 vs 8 days/p=0.008). Conclusions Both CAH and HAH present similarly, however, older patients with cognitive/physical impairments are at an increased risk. Early identification of high-risk patients and adherence to best practice guidelines is required.