Introduction: Hyponatraemia is the commonest electrolyte disturbance occurring in 1520% of inpatients (1), with significant clinical implications if mismanaged. We conducted a retrospective audit of our current management of hyponatraemia in our 1000 bedded trust.
Method: Data of patients with severe hyponatraemia (Na<125 mmol/l) admitted to hospital over 4 weeks (Aug 2011) was collected. Twenty randomly selected cases were reviewed focusing on initial assessment, management plan and associated morbidity.
Results: 218 cases were identified during the study period. Among the 20 selected cases, the lowest admission sodium was 112 mmol/l, the mean age was 73 years (2990) with 30% female, the cohort was also noted to have multiple co-morbidities (M=4.56). Assessment of hyponatraemia was only mentioned in 10 (50%) cases on the consultant post take ward round. Fluid balance was recorded only in eight (44%) cases and no patient was assessed for postural hypotension. Aetiologies identified were as follows; idiopathic (42%), drug induced (26%), SIADH (26%) and hypervolaemic causes (6%). Of the SIADH group the following investigations were performed; urinary sodium (60%), urine osmolality (60%) and serum osmolality (80%), thyroid function tests (20%) and 0900 h cortisol (14%). In relation to outcomes, fall in serum sodium was seen in 25%, with a rise evident in 65%, one case having >10 mmol rise in 24 h. The mean length of hospital stay (LOS) was 16 days (456 days) in comparison with a trust mean of 5 days, with 15% of prolonged LOS documented to be attributable to hyponatraemia. Mean sodium on discharge was 130 mmol/l (121137 mmol/l), one death occurred post discharge (Na 122 mmol/l).
Conclusion: Hyponatraemia is commonly seen in patients with multiple co-morbidities. Management remains challenging and attributes to prolonged LOS. A clear local guideline is needed and is currently under development, to improve the standard of care.
Huda MSB, Boyd A, Skagen K, Wile D, Van Heyningen C, Watson I, Wong S & Gill G. Investigation and management of severe hyponatraemia in a hospital setting. Postgrad Med J 2006 82 (965) 216219.