Analysis of the Epidemiology, Clinical Presentation and Therapy as Well as Therapy-associated Risk of Demyelination Syndrome in Patients With Profound Hyponatremia in the Emergency Department (ProfHN_in_ZNA)

Retrospective Analysis of the Epidemiology, Clinical Presentation and Therapy as Well as Therapy-associated Risk of Demyelination Syndrome in Patients With Profound Hyponatremia in the Emergency Department

Hyponatremia is a frequent cause for presentation to the emergency department (ED). While patients with chronic hyponatremia often exhibit minor symptoms, acute development of hyponatremia can lead to global cerebral edema, transtentorial herniation and death. The time course of hyponatremia development is usually not known to the treating physician at presentation. Hence, type and extent of therapy depend on the presence or absence of severe symptoms such as coma, seizures, obtundation or vomiting. It is believed that these are suggestive of increased cerebral pressure and indicative of cerebral edema. International guidance thus demands aggressive therapy with hypertonic saline at their occurrence. However, severe symptoms can also be found in patients with chronic hyponatremia (i.e., development in more than 48 hours) which are not at risk for developing cerebral edema due to adaptive counter measures in the brain. Although the percentage of patients with severe symptoms in chronic hyponatremia is considerably smaller than in acute hyponatremia, a higher incidence of chronic hyponatremia may lead to a larger overall number of severely symptomatic patients with chronic hyponatremia. The precise distribution of acute and chronic cases in the ED has not been established yet. In consequence, many patients with hyponatremia presenting with severe symptoms receive aggressive treatment in order to raise sodium levels, exposing them to the risk for overly rapid correction and osmotic demyelination syndrome (ODS). Current U.S. recommendations limit the sodium increase to a maximum of 8 mmol/L and 10-12 mmol/L in the first 24 hours in patients with high or low-to-moderate ODS risk, respectively. Similarly, the 2014 European Clinical Practice Guideline (ECPG) recommends a limit of 10 mmol/L in each 24h-period. These limits are often not accomplished in the real-world setting. In summary, weighing the risk of hyponatremia against complications associated with its (over-)correction constitutes a dilemma for the clinician. It will be strived to refine guidance on management of hyponatremia in patients with profound hyponatremia. Therefore, a better understanding of the proportions and characteristics of patients at risk for both cerebral edema and ODS is needed. The primary objective of this study is to determine the rate of hyponatremic patients who had already developed cerebral edema on admission and to identify patients who developed ODS during the index hospital stay. A secondary objective is a more detailed characterization of these subsets.

Study Overview

• Status: Completed
• Conditions: Hyponatremia

• Study Type: Observational
• Enrollment (Actual): 1000

Contacts and Locations

Study Locations

• Germany
  • Cologne, Germany, 50937
    • University Hospital of Cologne

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients with profound hyponatremia presenting to the emergency department

Description

Inclusion Criteria:

• Adult patients ≥18 years
• Plasma sodium ≤125 mmol/L in the initial blood sample after admission to the Emergency Department

Exclusion Criteria:

• Lack of follow-up sodium analyses within the first 24 hours after admission
• initial blood glucose >300 mg/dL

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rate of patients with cerebral edema	The primary aim is to determine the patient´s risk to develop cerebral edema, associated with hyponatremia and osmotic demyelination as a result of therapy, respectively. Determination at admission as evidenced by imaging studies in the time period index admission in the Emergency Department until referral from the Emergency Department	on admission and within 2 hours after admission
rate of patients who develop osmotic demyelination syndrome (ODS)	The primary aim is to determine the patient´s risk to develop cerebral edema, associated with hyponatremia and osmotic demyelination as a result of therapy, respectively. Determination as evidenced by imaging studies in the time period index admission until 90 days thereafter.	on admission and 90 days after admission

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Risk factors associated with hyponatremia	Are there specific risk factors apart from hyponatremia or its management that influence the development of cerebral edema, respectively?	on admission
Risk factors associated with osmotic demyelination syndrome	Are there specific risk factors apart from hyponatremia or its management that influence the development of osmotic demyelination syndrome, respectively?	on admission
Proportion of patients with severe symptoms and characterization of severe symptoms of hyponatremia	Determine the rate of patients with profound hyponatremia that exhibit severe symptoms such as vomiting, obtundation, seizures, coma and cardiorespiratory distress.	on admission
Proportion of patients, in which ODS was considered "confirmed", "highly likely" and "possible", considering clinical and/or radiological features of ODS	Determine the rate of patients, in which ODS was considered "confirmed" in patients with classical radiological findings, "highly likely" in patients with clinical features of and radiological findings consistent with ODS, and "possible" in patients with clinical but no radiological features (or that had not received imaging)	at study end, 1 year after study start

Collaborators and Investigators

• Sponsor: University of Cologne
• Investigators: Principal Investigator: Volker Burst, MD, University Hospital Cologne

Publications and helpful links

General Publications

• Burst V, Rabii R, Peto-Madew J, Persigehl T, Haneder S, Hackl MJ, Huser C, Trappe M, Cukoski S, Mollenhoff K, Suarez V. Severe Hyponatremia in the Emergency Department Incidence of Cerebral Edema and Risk of Osmotic Demyelination Syndrome. Acad Emerg Med. 2026 Jan;33(1):e70158. doi: 10.1111/acem.70158. Epub 2025 Oct 9.

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2024
• Primary Completion (Actual): December 31, 2025
• Study Completion (Actual): December 31, 2025

Study Registration Dates

• First Submitted: December 17, 2024
• First Submitted That Met QC Criteria: January 15, 2025
• First Posted (Actual): January 17, 2025

Study Record Updates

• Last Update Posted (Actual): April 30, 2026
• Last Update Submitted That Met QC Criteria: April 29, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Hyponatremia; demyelination; ODS; overcorrection
• Additional Relevant MeSH Terms: Nervous System Diseases; Metabolic Diseases; Water-Electrolyte Imbalance; Nutritional and Metabolic Diseases; Demyelinating Diseases; Hyponatremia
• Other Study ID Numbers: V1.0_23.09.2022; 22-1373-retro (Other Identifier: Ethics Committee)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Data base will be shared upon request

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No