Urea Therapy for Hyponatremia in Subarachnoid Hemorrhage (NAT-URE)

Hyponatremia is defined as a plasma sodium concentration below 135 mmol / L. This is a common occurrence (20-50%) during subarachnoid hemorrhage (SAH). Its appearance is often associated with vasospasm. It is associated with an increase in morbidity and mortality linked to induced neurological disorders. Hyponatremia is caused by two etiologies: the syndrome of inappropriate secretion of anti-diuretic hormone (SIADH), and the cerebral salt wasting syndrome, CSWS. Theoretically, these two entities are differentiated by the patient's volemia; in practice, this parameter is difficult to measure. In addition, the correction of hyponatremia is diametrically opposed according to its mechanism: water restriction in the case of SIADH, sodium intake in the event of CSWS. Urea is offered as a second-line treatment in the event of treatment failure to correct hyponatremia. However, the efficacy of this treatment is based on small, observational, retrospective studies. Moreover, the mechanism of action of urea remains poorly understood: it could be a hyperosmolar effect or passive renal reabsorption of sodium.

Study Overview

• Status: Active, not recruiting
• Conditions: Subarachnoid Hemorrhage; Hyponatremia; SIADH
• Intervention / Treatment: Drug: Urea; Other: PLACEBO

• Study Type: Interventional
• Enrollment (Actual): 52
• Phase: Not Applicable

Contacts and Locations

Study Locations

• France
  • Grenoble, France, 38043
    • University Hospital Grenoble

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients aged at least 18 years old
• Non-traumatic HSA
• Hyponatremia defined by a natremia less than 135 mmol / L and a high natriuresis, greater than 250 mmol / L despite well-managed saline intakes

Exclusion Criteria:

• Severe cardiac decompensation (LVEF <30%)
• Severe hepatic cirrhosis (PT <30%, ascites), known severe renal failure (GFR <30mL / min / 1.73m²)
• Blood urea> 25 mmol / L in the basal state
• Osmotherapy and diuretics in the last 48 hours
• Ongoing treatment with systemic corticosteroids
• Persons referred to in Articles L1121-5 to L1121-8 of the CSP corresponding to all protected persons: pregnant woman, parturient, nursing mother, person deprived of liberty by judicial or administrative decision, person subject to a legal protection measure.
• Patient not affiliated to a social security scheme
• Known hypersensitivity to any of the components of ergytonyl
• Contraindications to ergytonyl: taking curative anticoagulants, previously known and treated diabetic patients

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: EXPERIMENTAL GROUP; the experimental group will be treated during 5 days by urea dose per administration : 1g / kg / 24 hours in 2 or 3 doses morning, noon and evening (dose adjustment of urea according to weight)	Drug: Urea; the experimental group will be treated during 5 days by urea dose per administration : 1g / kg / 24 hours in 2 or 3 doses morning, noon and evening (dose adjustment of urea according to weight) If hyponatremia persists beyond D8 after initiation of the study treatment (urea or placebo), that is to say after the date of the collection of the primary endpoint, it will be possible to introduce corticosteroids (fludrocortisone or others). These treatments will be collated. If during patient monitoring the serum sodium exceeds 145 mmol / L, treatment should no longer be administered.
Placebo Comparator: CONTROL GROUP; the control group will be treated during 5 days by ergytonyl dose per administration : 5mL	Other: PLACEBO; the control group will be treated during 5 days by ergytonyl dose per administration : 5mL

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To demonstrate the effectiveness of urea therapy in correcting persistent hyponatremia despite adequate management during subarachnoid hemorrhage	Change in blood serum in mmol / L measured before initiation of treatment and on the day of discontinuation of treatment	5 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To compare the sodium intake required to correct the natremia.	Measurement of daily sodium intake in each group	8 days
To assess the impact of treatment on length of stay	Length of stay in intensive care and/or continuing care unit	3 months
To assess the impact of treatment on neurological outcome at 3 months from inclusion	Measurement of modified Rankin score	3 months
To assess the adverse effects of treatment	Prevalence of adverse effects of urea (headaches, digestive disorders, etc.)	3 months
Persistence of correction of natraemia 48H after cessation of treatment	Variation in natraemia mmol/L measured before introduction of treatment and 48 hours after cessation of treatment	48 hours after the end of treatment
To compare the speed of correction of natraemia	Average time taken for natraemia to correct to Na > 135 mmol/L after initiation of treatment.	5 days
To study the mechanism of action of urea	Daily plasma co-peptin levels in each group during treatment and 48 hours after cessation of treatment.	48 hours after the end of treatment

Collaborators and Investigators

• Sponsor: University Hospital, Grenoble
• Investigators: Principal Investigator: Perrine BOUCHEIX, MD, University Hospital, Grenoble

Publications and helpful links

General Publications

• Hall A, O'Kane R. The Extracranial Consequences of Subarachnoid Hemorrhage. World Neurosurg. 2018 Jan;109:381-392. doi: 10.1016/j.wneu.2017.10.016. Epub 2017 Oct 16.
• Mapa B, Taylor BE, Appelboom G, Bruce EM, Claassen J, Connolly ES Jr. Impact of Hyponatremia on Morbidity, Mortality, and Complications After Aneurysmal Subarachnoid Hemorrhage: A Systematic Review. World Neurosurg. 2016 Jan;85:305-14. doi: 10.1016/j.wneu.2015.08.054. Epub 2015 Sep 7.
• Hannon MJ, Behan LA, O'Brien MM, Tormey W, Ball SG, Javadpour M, Sherlock M, Thompson CJ. Hyponatremia following mild/moderate subarachnoid hemorrhage is due to SIAD and glucocorticoid deficiency and not cerebral salt wasting. J Clin Endocrinol Metab. 2014 Jan;99(1):291-8. doi: 10.1210/jc.2013-3032. Epub 2013 Dec 20. Erratum In: J Clin Endocrinol Metab. 2014 Mar;99(3):1096. Javadpur, M [corrected to Javadpour, M].
• Nakajima H, Okada H, Hirose K, Murakami T, Shiotsu Y, Kadono M, Inoue M, Hasegawa G. Cerebral Salt-wasting Syndrome and Inappropriate Antidiuretic Hormone Syndrome after Subarachnoid Hemorrhaging. Intern Med. 2017;56(6):677-680. doi: 10.2169/internalmedicine.56.6843. Epub 2017 Mar 17.
• Hoorn EJ, Zietse R. Diagnosis and Treatment of Hyponatremia: Compilation of the Guidelines. J Am Soc Nephrol. 2017 May;28(5):1340-1349. doi: 10.1681/ASN.2016101139. Epub 2017 Feb 7.

Study record dates

Study Major Dates

• Study Start (Actual): December 3, 2020
• Primary Completion (Actual): December 3, 2024
• Study Completion (Estimated): August 1, 2025

Study Registration Dates

• First Submitted: September 10, 2020
• First Submitted That Met QC Criteria: September 10, 2020
• First Posted (Actual): September 17, 2020

Study Record Updates

• Last Update Posted (Actual): April 16, 2025
• Last Update Submitted That Met QC Criteria: April 11, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Keywords: SAH; hyponatremia; SIADH; urea; copeptine
• Additional Relevant MeSH Terms: Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Pathologic Processes; Metabolic Diseases; Water-Electrolyte Imbalance; Intracranial Hemorrhages; Hemorrhage; Subarachnoid Hemorrhage; Hyponatremia
• Other Study ID Numbers: 38RC19.189

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No