Simple guidelines for diagnosing and treating a salt imbalance occurring in up to 30% of hospitalised patients are published in the European Journal of Endocrinology. The guidelines recommend that any hospital-based clinician must be able to correctly diagnose, classify and treat hyponatraemia, which is associated with morbidity, mortality and length of hospital stay in a wide range of conditions.
Hyponatraemia is a complicated disorder of water balance, with a relative excess of body water compared to sodium and potassium (defined as a serum sodium concentration <135mmol/l). It has a wide variety of underlying causes, and results in swelling (known as cellular oedema). Cells of the brain are particularly vulnerable to damage by swelling, making severe cases medical emergencies. Milder cases can be associated with impaired mobility and cognition, as well as osteoporosis and fracture.
The guideline development group, comprising representatives from the European Society of Intensive Care Medicine (ESICM), the European Society of Endocrinology (ESE) and the European Renal Association - European Dialysis and Transplant Association (ERA-EDTA), conducted a literature review to collate the best available evidence on the diagnosis and management of hypotonic hyponatraemia.
The guidelines describe a pathway for diagnosis which is less reliant on specialist laboratory resources, and can be conducted in the general hospital setting, in particular during 'out-of-office hours'.
The treatment pathway described in the document focuses more closely on the patients' symptoms, giving lower priority to biochemical diagnosis. The guidelines recommend that as the risks to the patient's brain are so great, in severe cases action is more important than investigation until the patient is stabilised.
The full guidelines can be downloaded for free from the European Journal of Endocrinology, the official journal of the European Society of Endocrinology.
Speaking on behalf of the European Society of Endocrinology, Professor Bruno Allolio said:
"Hyponatraemia can be a life-threatening condition seen by any doctor in the hospital setting, at any time of day. It is a significant clinical problem which we see quite often on the wards, and it is associated with morbidity, mortality and a longer hospital stay.
"In an emergency situation any hospital-based doctor may need to recognise and treat hyponatraemia.
"Our new guidelines represent the best available evidence in an easy to follow format. We have laid out our diagnosis and treatment strategies in simple algorithms, always bearing in mind the generalist audience that may most frequently encounter the condition."