Endocrine Abstracts

Hyponatraemia is common in acute medical admissions, to district general hospitals presenting with neurological complications and increasing length of stay. We have carried out an audit against the following standards: full drug history; assessment of volume status; paired plasma and urinary osmolalities; appropriate fluid and Na⁺ management and monitoring; and target Na⁺>125 mmol/l on discharge.

Fifty two patients with hyponatraemia defined as serum Na⁺<125 mmol/l, were identified by computerised search of biochemistry lab data over a period of 57 days. An audit proforma was used and individual case notes were reviewed. We included patients who had a hospital stay for at least 48 h. ITU, palliative, post surgical patients, patients with uncontrolled diabetes (psuedohyponatraemia), advanced cardiac, renal and liver disease were excluded, five notes could not be traced.

The remaining 20 patients had documentation of relevant drug history.13/20 (65%) were on diuretics; which were continued in 4/13 (30.7%) anticonvulsants were identified as cause in 3/20 (15%), which were continued in all. Malignancy was identified as the cause in 2/20 (10%). No cause was documented in 4/20 (20%). All patients had documentation of volume status. Of 9/20 (45%) patients had paired plasma and urinary osmolalities and sodium in the first 24 h. Fluid management was appropriate in 7/20 (35%) of patients. Of 8/20 (40%) of patients had appropriate monitoring of sodium levels, in relation to the degree of hyponatraemia. Sodium shifts were appropriate, less than 10 mmol/l in 24 h, in 16/20 (80%) patients.2/20 (10%) had more than 10 mmol/l increase in sodium in 24 h. Of 2/20 (10%) did not have sodium levels monitored.18/20 (90%)patients on discharge had Na⁺>125 mmol/l.

Where drugs were thought to be the cause they were stopped appropriately. We have identified significant deficiencies in initial biochemical investigations, fluid management and lack of appropriate monitoring during correction of hyponatraemia. We are now implementing guidelines and education strategies to improve management of hyponatraemia to reduce length of stay and potential further morbidity.