Endocrine Abstracts

Hyponatraemia is the commonest electrolyte disturbance in hospital patients. It may be observed in up to 30% of cases and it has been clearly associated with an increased morbidity and mortality in a diverse array of clinical scenarios. Despite the frequency of the problem, robust evidence examining its importance and comparing treatment options has traditionally been lacking. However, recent years have seen the publication of high-quality prospective studies evaluating the epidemiology, clinical importance and management of hyponatraemia. Several clinical practice guidelines for the assessment and management of hyponatraemia have been published. However, hyponatraemia is encountered in such a broad spectrum of patients, often with complex comorbidities, that a physician’s judgement and individualised management are still required in everyday clinical practice. The commonest cause of hyponatraemia in hospital is the syndrome of inappropriate anti-diuretic hormone secretion (SIADH). However, glucocorticoid deficiency can mimic this syndrome, accounting for up to 4% of cases originally diagnosed as SIADH. Fluid restriction has been the mainstay of treatment for SIADH for many decades. The safety and efficacy of this treatment has not been rigorously examined in prospective trials. Furthermore, it can be practically difficult to implement and maintain in hospital patients. Recently, following the publication of prospective, randomised controlled trials, vasopressin receptor antagonists have been approved for the treatment of SIADH. Clinical experience with these agents is growing worldwide. Severe symptomatic hyponatraemia is particularly challenging. It requires urgent, careful management, with frequent monitoring of serum sodium, to reduce the risk of mortality and avoid permanent neurological injury. This interactive clinical session will discuss cases of hyponatraemia in hospital patients to illustrate complexities in management and suggest approaches to assessment and treatment.