An interventional study of Standard Care and aSID/ChU Guided Therapy in Thiazide Associated Hyponatremia, sponsored by University Hospital, Basel, Switzerland. Recruiting at 1 site in Switzerland. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-02-11.
Sponsored by University Hospital, Basel, Switzerland · Not applicable, Interventional, and Treatment
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.
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.
164 studies on the registry are indexed under Hyponatremia; 16 are open to participants now.
This study's planned enrollment of 136 is above the median of 60 across 98 interventional studies indexed under Hyponatremia.
Browse Hyponatremia studies →University Hospital, Basel, Switzerland is the lead sponsor of 990 studies on the registry; 189 are open to participants now.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
TAH patients randomised to the Standard Care Group will be followed by a physician not involved in the study.
Other: Standard Care
TAH patients randomised to the aSID/ChU Guided Therapy Group will have aSID and ChU determined and, depending on the results, will be assigned to fluid administration with saline or drinking restriction.
Other: aSID/ChU Guided Therapy
Standard diagnosis and therapy procedures at physician's discretion.
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.
Serum Sodium Level
Percentage of patients with an increase in serum sodium level \> 4 mmol/l at day 1 or \> 134 mmol/l in maximum 3 days in the aSID/ChU guided therapy group as compared to the standard care (control) group.
Time frame: at baseline, 24 hours and up to 72 hours
Descriptive analyses: Changes in aSID in relation to changes in serum sodium levels
Descriptive analyses: Changes in aSID in relation to changes in serum sodium levels.
Time frame: at baseline, 24 hours and up to 72 hours
Descriptive analyses: Changes in ChU in relation to changes in serum sodium levels
Descriptive analyses: Changes in ChU in relation to changes in serum sodium levels.
Time frame: at baseline, 24 hours and up to 72 hours
Diagnostic performance analyses of: aSID and ChU
Sensibility, specificity, negative predictive value and positive predictive value at different cut-offs for adequate therapy of TAH. An adequate therapy of TAH is a therapy by which the patient reaches the primary endpoint independent from randomization arm.
Time frame: at baseline, 24 hours and up to 72 hours
Diagnostic performance analyses of: aSID measured in blood gas analysis
Sensibility, specificity, negative predictive value and positive predictive value at different cut-offs for adequate therapy of TAH. An adequate therapy of TAH is a therapy by which the patient reaches the primary endpoint independent from randomization arm.
Time frame: at baseline, 24 hours and up to 72 hours
Diagnostic performance analyses of: clinical volume status assessment
Sensibility, specificity, negative predictive value and positive predictive value at different cut-offs for adequate therapy of TAH. An adequate therapy of TAH is a therapy by which the patient reaches the primary endpoint independent from randomization arm.
Time frame: at baseline, 24 hours and up to 72 hours
Diagnostic performance analyses of: not-invasive instrumental volume status assessment
Sensibility, specificity, negative predictive value and positive predictive value at different cut-offs for adequate therapy of TAH. An adequate therapy of TAH is a therapy by which the patient reaches the primary endpoint independent from randomization arm.
Time frame: at baseline, 24 hours and up to 72 hours
Diagnostic performance analyses of: other hormones such as aldosterone, renin, arginine-vasopressin
Sensibility, specificity, negative predictive value and positive predictive value at different cut-offs for adequate therapy of TAH. An adequate therapy of TAH is a therapy by which the patient reaches the primary endpoint independent from randomization arm.
Time frame: at baseline, 24 hours and up to 72 hours
Plan to share: Undecided
Started May 2024 (actual). Primary completion is estimated for Apr 2027, 35 months after the start.
Of 24 interventional studies with no phase under Hyponatremia, half reached primary completion within 24 months of starting (the median), counting those still running; a quarter within 12 and three quarters within 48. This study's planned 35 months is above that.
How these figures are worked out, and which studies are left out of them.
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