Background: Hyponatraemia is encountered in 15−20% of inpatients but remains suboptimally managed. It leads to increased morbidity, length of stay and mortality. A closed-loop audit on investigating and managing inpatients with hyponatraemia was conducted, to identify pitfalls in management.
Method: A retrospective audit of general medical inpatients admitted over three months with a serum sodium level of less than 130 mmol/l was conducted. Relevant initial and follow up investigations and outcomes were reviewed. Subsequent interventions included teach-in sessions for doctors and nurses as well as raising awareness through posters with an algorithm for investigation and management of hyponatraemia displayed in the wards. The audit was repeated after four months.
Results: There were 17 patients (mean age 74 years) in the first audit and 14 patients (mean age 76 years) in the second. The re-audit showed that volume status assessment improved from 65% to 78%. Fluid balance or daily weight recording improved from 17% to 71%. The use of appropriate further biochemical investigations (such as paired urine and serum osmolalities, urine sodium, cortisol and thyroid hormone levels) improved from 6% to 42%. Improvement in serum sodium levels in the first 24 h was similar in the two audits (82% vs.85%) and levels in all patients in both audits increased but not more than 10 mmol/l in 24 h. Mean length of stay was 9 days in the first audit and 11 days in the second. Mortality rates were 3/17 and 4/14 in the first and second audits respectively.
Conclusions: Management of hyponatraemia remains challenging but can be improved by raising awareness and through education. A local guideline is currently under development to facilitate this. Outcomes are more difficult to influence, which may reflect a cohort of older patients with co-morbidities.