Hyponatraemia in elderly emergency department patients: a marker of frailty.

BACKGROUND: Details on hyponatraemia in the emergency department are limited, especially regarding older patients, a population more susceptible to hyponatraemia and its effects. Our objective was to gain insight into the prevalence, aetiology, treatment and prognosis of clinically relevant hyponatraemia in elderly emergency department patients. The impact of the severity of hyponatraemia on outcome was a secondary objective. METHODS: A retrospective cohort study of 1438 internal medicine patients aged ≥ 65 years presenting to the emergency department between 1 September 2010 and 31 August 2011 was performed. Clinically relevant hyponatraemia was defined as a serum sodium level < 130 mmol÷l. The reference group had a serum sodium level of 130-145 mmol÷l. Hyponatraemia was subdivided into moderate (129-125 mmol÷l), and severe (< 125 mmol÷l). RESULTS: Ninety-one elderly patients (6.3%) were hyponatraemic at presentation to the emergency department. The main causes were the use of diuretics, hypovolaemia, and the syndrome of inappropriate antidiuretic hormone secretion (57.1%). Hyponatraemia was associated with higher admission rates (93.4 vs. 72.9%) and longer hospital stay (8 vs. 6 days) vs. the reference group. Three-month survival rate in hyponatraemic elderly patients was 74% (95% CI 64-84%) vs. 83% (95% CI 81-85%) in the reference group. Moderate hyponatraemia was associated with an increased risk of death (HR 1.7, 95% CI 1.2-2.4) vs. the reference group after multivariable adjustment for age and comorbidity. CONCLUSION: Hyponatraemia, a common electrolyte disturbance among elderly internal medicine patients presenting to the emergency department, was associated with higher admission rates, longer hospital stay, and higher mortality rates. In particular, moderate hyponatraemia was a marker of underlying frailty and predictive of mortality.

[The Kleine-Levin syndrome and the treatment with methylphenidate]. / Het syndroom van Kleine-Levin en de behandeling met methylfenidaat.

A 17-year-old man was referred to the Med-Psych-Unit because of recurrent episodes of hypersomnia, megaphagia, hypersexual behaviour and cognitive disturbances. Over the period of three years he suffered more than 10 episodes of hypersomnia each lasting 8 to 16 days. The clinical presentation was suggestive of the Kleine-Levin syndrome. The symptoms disappeared after treatment with methylphenidate, but it was not clear whether this could be attributed to the medication or to the self-limiting character of the illness. The Kleine-Levin syndrome is often clinically not recognised due to the variation in the symptoms and the lack of objective diagnostic examination.