NCT06381934

Validation of New Diagnostic Indices to Simplify Hyponatremia Therapy Assessment in Patients on Thiazide Diuretics

Validation of Diagnostic Indices to Simplify Hyponatremia Therapy Assessment - A Randomized, Controlled, Parallel-group Clinical Trial in Hospitalized Patients on Thiazide Diuretics (THAT Study)

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 136 (estimated)
• Sponsor: University Hospital, Basel, Switzerland · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

This study is looking at two new parameters, aSID and ChU, to see if these can help physicians to distinguish between different causes of low sodium levels (hyponatremia) in Patients taking a medicament against high blood pressure (thiazide). Researchers also want to see if using these new parameters to decide on treatment works just as well, or better, than the current standard treatments.

Detailed description

Thiazide or thiazide-like diuretics associated hyponatremia (thiazide associated hyponatremia, TAH) has a high prevalence in hospitalized patients. Patients might present either with a hypovolemic hyponatremia due to volume loss as a diuretic effect of thiazide, or with a syndrome of inadequate antidiuresis (SIAD) like hyponatremia in need of fluid restriction. Canonical urine indices are not useful in differential diagnosis, being directly influenced by thiazide itself. Current guidelines suggest the use of a clinical volume status assessment, but this approach has a poor diagnostic performance, with less than 50% of patients being rightly diagnosed thru that. The investigators showed in a retrospective analysis the possible role of strong apparent ion difference (aSID) and of chloride and potassium levels in urine (ChU) in differential diagnosis of TAH. The goal of this study is to investigate prospectively whether implementation of aSID and, in case of inconclusive aSID, ChU, allows a correct differential diagnosis and treatment of TAH.

Conditions

• Thiazide Associated Hyponatremia

Interventions

Type	Name	Description
OTHER	Standard Care	Standard diagnosis and therapy procedures at physician's discretion.
OTHER	aSID/ChU Guided Therapy	Stopping of thiazide therapy. Measure aSID: * aSID between 39 and 42 mmol/l : measure ChU * ChU lower than 15mmol/l : fluid administration (0.9% NaCl infusion, 250-500 ml over 2 hours followed by 10-20 ml/kg/24h) * ChU higher than 14.9 mmol/l : drinking restriction (of at least 50% of usual drinking volume) * aSID higher than 42 mmol/l : fuid administration (fluid administration (0.9% NaCl infusion, 250-500 ml over 2 hours followed by 10-20 ml/kg/24h) * aSID lower than 39 mmol/l : drinking restriction (of at least 50% of usual drinking volume) The aSID/ChU guided therapy will take place for a minimum of 1- and a maximum of 3 days after enrolment. Treatment and adherence to the treatment will be assessed and re-evaluated at least daily for 3 days or till discharge or sodium normalization.

Timeline

• Start date: 2024-05-06
• Primary completion: 2027-04-01
• Completion: 2027-04-01
• First posted: 2024-04-24
• Last updated: 2026-02-11

Locations

1 site across 1 country: Switzerland