Severe symptomatic hyponatraemia in Europe: Insights into current clinical practice

Introduction For the treatment of severe symptomatic hyponatremia, the European Society of Endocrinology (ESE) guidelines (2014) recommend a bolus-wise strategy using hypertonic saline (HTS). However, there are recent controversies regarding the risk of overcorrection and osmotic demyelination syndrome (ODS), leading to significant heterogeneity in practice. The aim of this survey was to evaluate clinical practices and perspectives of endocrinologists across Europe in managing severe symptomatic hyponatremia. Methods A web-based anonymous cross-sectional survey (REDCap®), endorsed by ESE, was disseminated from 06, 2024 to 02, 2025. Data were analyzed using R-Studio. Results A total of 662 responses were received. After excluding incomplete and non-European responses, 439 responses from 36 countries were analyzed. Most responses were received from university hospitals (68.6%) and senior clinicians (68.1%). Thirty-one percent of clinicians had experience using both bolus and continuous infusions in managing severe symptomatic hyponatremia, while sole bolus or continuous infusion therapy was preferred by 32% and 23%, respectively. Preferred bolus dosage and strength were 3% 100 mL (28%) and 3% 150 mL (19%), while 5% preferred a weight-based dosage. Most (84%) clinicians preferred one bolus infusion followed by a blood test before repeating a second. Thirty-four percent of respondents had encountered ≥1patient with suspected or confirmed ODS in their practice, with 55% reported ODS being associated with sodium overcorrection. Discussion This is the first European survey on the management of severe symptomatic hyponatremia, offering valuable insights into real-life clinical practice. Our findings highlight ongoing uncertainties in treatment strategies and underscore the need for future research and evidence-based review of the ESE guidelines.