Medical outcome of psychiatric inpatients with admission hyponatremia

Hyponatremia at time of inpatient admission is associated with increased severity of illness and mortality in patients hospitalized for treatment of medical conditions. This study was conducted to determine the clinical outcome of psychiatric inpatients with admission hyponatremia. The cohort comprised 1000 adults consecutively admitted to a free-standing psychiatric hospital in 2010. Emergency transfer to a general hospital was used as a proxy marker for poor medical outcome. The point prevalence of hyponatremia (sodium level < 136 mEq/l) at admission was 6.49%. Older age and a diagnosis of arterial hypertension were independent correlates of admission hyponatremia. Medical deteriorations occurred in 26.7% of hyponatremic patients and 13.1% of those with normal sodium levels. Admission hyponatremia is associated with an increased rate of significant medical deteriorations of psychiatric inpatients and should trigger enhanced clinical monitoring to identify and treat somatic disorders.