Clinical Research Directory

Hyponatremia - Complications, Prognosis, Epidemiology in Finnish Tertiary Care

Study Objectives and Hypothesis To determine the incidence of hyponatremia at TYKS and the factors associated with it. To assess how rapidly hyponatremia was corrected and how the rate of correction affected patient prognosis. To evaluate treatment modalities and their impact on patient prognosis, length of hospital stay, and their appropriateness in comparison with national and international treatment guidelines. To determine the incidence of osmotic demyelination at TYKS and the factors associated with it. To assess other complications and their clinical significance. To evaluate the impact of hyponatremia on various endpoints, such as mortality, length of hospital stay, seizures, confusion, and similar outcomes.

Effect of Protein Supplementation and Fluid Restriction on Plasma Sodium Levels in Patients Undergoing Pituitary Surgery

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.

Effects of the SGLT2 Inhibitor Empagliflozin in Patients With Euvolemic and Hypervolemic Hyponatremia

Hyponatremia is the most common electrolyte derangement occurring in hospitalized patients. It is usually classified as hypovolemic, euvolemic or hypervolemic. The most common aetiology of euvolemic hyponatremia is the syndrome of inappropriate antidiuresis (SIAD). Hypervolemic hyponatremia is common in patients with congestive heart failure (CHF) (10-27%) and liver cirrhosis (up to approximately 50%). In SIAD, the regulation of arginine vasopressin (AVP) secretion is impaired which leads to free water retention. In CHF and liver cirrhosis, the effective arterial blood volume is decreased leading to non-osmotic baroreceptor mediated AVP release and consecutive free water retention. Current treatments of euvolemic and hypervolemic hyponatremia, including the most used treatment fluid restriction, are of limited efficacy. Sodium-Glucose-Co-Transporter 2 (SGLT2) inhibitors reduce glucose reabsorption in the proximal tubule, resulting in glucosuria and consecutive osmotic diuresis. A placebo-controlled randomized trial of our group has shown that a short-term, i.e. a 4-days administration of the SGLT2 inhibitor empagliflozin (Jardiance)® in addition to fluid restriction was effective in increasing the serum sodium concentration in 87 patients with SIAD-induced hyponatremia. The effect of empagliflozin (Jardiance)® without additional fluid restriction is however not yet known. Large randomized controlled trials have shown that SGLT2 inhibitors reduced hospitalization for heart failure in patients with, and more recently without type 2 diabetes. No studies have investigated the effect of SGLT2 inhibitors in hypervolemic hyponatremia. To evaluate the effect of empagliflozin (Jardiance)® in eu- and hypervolemic hyponatremia, a randomized placebo-controlled study is needed.

Regulation of Extracellular Sodium in End Stage Renal Disease Upon Volume and Electrolyte Challenges

Hyponatremia is the most common electrolyte disorder of all and can be observed in more than 30% of all patients in hospitals. Osmotic homeostasis of body fluids is essential for survival of all living creatures. It is widely accepted that extra- and intracellular osmolalities are in equilibrium at all times and thus, changes in the extracellular osmolality will lead to either shrinkage or swelling of cells which can be detrimental. In severe cases, it can lead to swelling of the brain and death. Even in less dramatic scenarios, symptoms such as epileptic seizures, headaches, depression and dizziness exist, leading to an increased risk of fractures, hospital admissions and a considerable burden for affected patients. As short-term defense against osmotic stress, each individual cell is capable of actively externalizing or internalizing osmotically active solutes which restores normal or near-normal cell volume at the expense of an altered milieu interior. Obviously, there must be limitations to this strategy if intracellular integrity is meant to be kept stable. It has therefore been postulated that, apart from this cell-immanent mechanism, extracellular and intracellular electrolyte stores could assist in buffering osmotic imbalances. The Edelman formula states that extracellular sodium is determined by the total amount of exchangeable body sodium (the major extracellular cation) plus potassium (the major intracellular cation) divided by total body water. Several studies have shown, that it only partially explains the changes in patients outside the osmotic equilibrium. To better understand these physiological responses might not only promote the researcher's insight into the most basic cellular self-defense systems by measuring and comparing extra- and intracellular electrolyte concentrations with estimated changes in a patient that will be intravenously challenged with either water or sodium chloride 3%. The evolution over time of extra- and intracellular sodium and other electrolytes will be assessed quantitatively in patients with impaired renal function after water or sodium chloride (NaCl) administration.

Protein Supplementation in Hyponatremia Due to the Syndrome of Inappropriate Antidiuresis

The goal of this study is to assess the impact of protein supplementation on hyponatremia caused by the syndrome of inappropriate antidiuresis during hospitalization.

Systematic Use of DDAVP to Prevent Serum Sodium Overcorrection in Severe Hyponatremia

ICU patients with severe hyponatremia and a high risk of rapid SNa overcorrection.

Urea Therapy for Hyponatremia in Subarachnoid Hemorrhage

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.

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.

Hyponatremia Volume Status Analysis by Point-of-care Ultrasound

This observational study aims to analyze the time of correction of hyponatremia in patients within an internal medicine ward. The researchers will assess volume status using both clinical evaluation and point-of-care ultrasound. Patients will be categorized based on whether they have the same volume status determined clinically and by ultrasound or a different status between the two methods. By tracking sodium levels daily until normalization, the study will compare the time of hyponatremia correction between the two groups.

Saline Infusion Test in Hyponatremia

Observational study of biochemical volume biomarker levels in response to a standardized intravenous isotonic saline infusion in patients with hyponatremia.