Endocrine Abstracts

Introduction: Disorders of plasma sodium are one of the commonest electrolyte abnormalities affecting acutely unwell patients. The North Middlesex is a busy district general hospital with a diverse population. We reviewed our hypernatraemic population to identify possible trends in age, demographics and outcomes.

Methods: Through the biochemistry laboratory, we identified all patients with sodium level above 145 mmol/L who were acute inpatients or attended the Emergency Department in May or October 2017. Using the hospital records system, we matched patients to their demographic details, place of residence on admission and discharge, sodium level on admission, peak sodium during admission and final outcome including mortality in-hospital and within 30 days of discharge. We performed simple descriptive statistics by applying correlation coefficient calculation and t-test analysis.

Results: The hospital pathology system returned serum sodium results above 145 mmol/L for 589 patients, of which 84 were analysed in detail. Patients with peak sodium above 165mmol/L represented 1% of all results. Mean age increased with severity of hypernatraemia. There was a moderately positive relationship between degree of hypernatraemia at point of discharge and mortality (r=0.49). There was a statistically significant difference between sodium on admission and on discharge (P<0.05). There was no significant difference between the sodium values on admission for nursing home versus non-nursing home residents (P=0.18). All patients with peak sodium >165 mmol/L had an unplanned re-admission to hospital within 3 months.

Discussion/Conclusion: Hypernatraemia is associated with increased mortality and is more common with advancing age. There was no difference between nursing home versus non-nursing home residents but this could be specific to our patient demographic and associated cultural backgrounds. Our data suggests that hypernatraemia is a potentially correctable medical problem but the patients are nonetheless at increased risk of future acute hospital admissions.