An interventional study of Fluid restriction and Dietary protein supplementation in Hyponatremia and Pituitary Surgery, 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 2026-02-03.
Sponsored by University Hospital, Basel, Switzerland · Not applicable, Interventional, and Prevention
The investigators are conducting this study to investigate new preventive measures for patients with low sodium levels (hyponatremia), which can occur after surgery on the pituitary gland. This hyponatremia is often caused by the syndrome of inappropriate antidiuresis (SIAD). SIAD occurs when the pituitary gland secretes too much antidiuretic hormone. The antidiuretic hormone causes the kidneys to absorb more water. This dilutes the sodium in the blood and leads to hyponatremia. Low sodium levels are particularly common after pituitary surgery, as the procedure on the pituitary gland can lead to increased reactive secretion of antidiuretic hormone. At present, apart from educating patients about the symptoms of hyponatremia, there are no established standard measures for prevention after pituitary surgery. If hyponatremia is present, it is currently treated primarily by fluid restriction, which is not always pleasant or easy to adhere to. With this study, the investigators want to investigate whether protein supplementation or fluid restriction between day 4 and day 9 after surgery can serve as a preventive measure to stabilize sodium levels after pituitary surgery and improve the quality of life of patients.
Disturbances in water balance, often due to disturbed arginine vasopressin (AVP) secretion from pituitary stalk and/or posterior lobe damage/manipulation, are common complications following pituitary surgery. This can result in either AVP deficiency, causing polyuria and polydipsia, or AVP excess, leading to water retention and dilutional hyponatremia (syndrome of inappropriate antidiuresis, SIAD). SIAD affects up to 30% of patients, typically developing between days 4 and 14 post-surgery, with a peak around day 7. While usually mild, severe hyponatremia is a leading cause of hospital readmission. Management includes fluid restriction, oral urea, or, in severe cases, hypertonic saline and AVP receptor antagonists.
Non-medicinal preventive strategies, such as prophylactic fluid restriction, have demonstrated efficacy in reducing SIAD incidence and hospital readmissions, but the optimal protocol remains unestablished. Dietary protein supplementation has recently emerged as a potential novel intervention, leveraging osmotic diuresis from increased endogenous urea production derived from the physiological amino-acid metabolism to raise plasma sodium levels. However, no data in the postoperative setting are available
This study aims to compare protein supplementation and fluid restriction to standard care (no specific intervention) in preventing post-pituitary surgery hyponatremia. From days 4 to 9 post-surgery, participants will receive one of the three treatments: Treatment A: Patients will limit their total daily fluid intake to a maximum of 1000 ml Treatment B: Patients will consume an additional 80 grams of protein daily through two 150 ml protein drinks (40 grams of protein each, MOLTEIN PURE Drink, OMANDA) in various flavors. Treatment C: Patients will not receive specific instructions. They will follow standard post-operative care and serve as a control group.
164 studies on the registry are indexed under Hyponatremia; 16 are open to participants now.
This study's planned enrollment of 282 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:
Post-Inclusion Exclusion criteria (day 3 post-surgery, i.e.,time of randomization): - AVP deficiency diagnosed on post-operative day 3
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.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
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.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Patients will limit their total daily fluid intake
Dietary Supplement: Fluid restriction
Patients will consume additional protein daily
Dietary Supplement: Dietary protein supplementation
Patients will not receive specific instructions.
Dietary Supplement: Standard post-operative care
Patients will limit their total daily fluid intake to a maximum of 1000 ml, including any liquids of their choice, such as water, milk, or juice.
Patients will consume an additional 80 grams of protein daily through two 150 ml protein drinks (40 grams of protein each, MOLTEIN PURE Drink, OMANDA) in various flavors. They can distribute the drinks throughout the day and drink other fluids freely based on thirst.
Patients will not receive specific instructions on protein supplementation or fluid restriction. They will follow standard post-operative care and drink or eat freely based on natural appetite and thirst.
Odds ratio of treatment failure (intervention compared to standard of care)
The primary objective is to evaluate the effectiveness of fluid restriction (Treatment A), and dietary protein supplementation (Treatment B) compared to the current standard care with no specific intervention and no fluid management guidance (Treatment C) in preventing treatment failure, defined at day 9 as a decrease in plasma sodium by at least 4 mmol/lL from baseline, and hyponatremia (plasma sodium \<135mmol/L) or a decrease of at least 1 point in the MoCa score compared to baseline.
Time frame: 3 days post-surgery (time of randomization), and day 9 post-surgery.
Plan to share: Undecided
No publications or documents are linked to this record.
Started Jan 2026 (actual). Primary completion is estimated for Oct 2028, 32 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 32 months is above that.
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