4CPS-018 Efficacy of urea in the treatment of hyponatraemia in syndrome of inappropriate antidiuretic hormone secretion

Background and importance The consequence of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) is a hypotonic hyponatraemia. Urea is a well tolerated therapeutic option indicated to correct sodium levels, acting as an osmotic diuretic, eliminating a large amount of water in urine accompanied by an increase in plasma sodium concentration. Aim and objectives To evaluate the efficacy of urea in controlling hypernatraemia due to SIADH in a third level hospital. Material and methods This was a quasi-experimental study. Patients with hyponatraemia treated with urea in 2019 were included. The main variable of our study was serum sodium level before treatment with urea at 24 hours, 48 hours, 14 days and 60 days. Age and sex were included as secondary variables. There were no extreme outliers and the data were normally distributed for each measured time, as assessed by box plot and the Shapiro–Wilk test (p>0.05), respectively. A one-way repeated measures ANOVA was conducted to determine whether there was a statistically significant difference in sodium concentration before and after treatment with urea. The analyses were performed using the SPSS/PC statistical programme (V.24.0 for Windows, SPSS Inc, Chicago, Illinois, USA). Results Thirty-three patients were treated with urea for 9 months. Of these, 67% were men and mean age was 77±13 years. Serum sodium levels before treatment and at 24 hours, 48 hours, 14 days and 60 days were 125±4, 127±5, 129±5, 134±4 and 134±4 mg/dL respectively. Time did not elicit statistically significant changes in sodium levels before and after treatment with urea (F=4.1, p=0.074). Conclusion and relevance In the study, there were no significant differences in plasma sodium values before and after urea treatment, so we did not demonstrate the efficacy of urea. The main drawback in the study was the small population analysed. References and/or acknowledgements No conflict of interest.