Introduction: Hyponatraemia is defined as serum sodium concentration <135 mmol/l. It is the most common electrolyte disorder encountered in clinical practise. It is associated with an increase in mortality and length of stay, independent of diagnosis and clinical variables. Despite this it is often inadequately investigated and poorly managed. As a number of endocrine conditions can cause hyponatraemia, endocrinologists often have the necessary clinical skills and expertise to manage these patients.
Methods: A retrospective audit was performed of patients admitted to The Great Western Hospital (GWH) serum sodium of 127 mmol/l or less on admission, over a 3-month period. The aims were to evaluate how hyponatraemia is investigated and whether specialist input from the endocrinology team improves the management of these patients.
Results: Seventy-five patients were included in the audit; 27 males (36%) and 48 females (64%). The mean age was 75 years (range 3794 years). All patients had a serum sodium of 127 mmol/l or less on admission: mean 122 mmol/l (range 108127 mmol/l). Only 65% of patients had hyponatraemia documented as either a diagnosis or problem. Only 28% of patients had their fluid status documented. Eight investigations were identified as essential when investigating patients with hyponatraemia. Only 4% of patients had all eight investigations completed during admission. Less than 27% of patients had a urine sodium, urine osmolality and serum osmolality requested during admission. Only seven patients (9%) admitted with hyponatraemia were either referred to the endocrinology team or were reviewed by the endocrinology team during admission. These patients had an average of 6.9 out of eight of the essential investigations, whereas those patients not reviewed by endocrinology had an average of 3.4 out of the eight.
Discussion: This audit confirms that hyponatraemia is often not recognised, inadequately investigated and poorly managed. Results suggest that an endocrine opinion is rarely requested and that patients who are reviewed by a specialist are more likely to have appropriate investigations requested, thereby increasing the chance of a being correctly diagnosed and managed.