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

Official title

Regulation of Extracellular Sodium in End Stage Renal Disease Upon Volume and Electrolyte Challenges - a Prospective Trial.

Overview

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.

Interventions

• Other Water administration
  Intravenous administration of water (Aqua ad injectabilia) until a decrease of plasma sodium of 5 to 8 mmol/l has been achieved
• Other NaCl-Administration
  Intravenous administration of NaCl 3% until an increase of plasma sodium of 5 to 8 mmol/l has been achieved

Primary outcome measures

• acute changes of extracellular osmolality [Time frame: 300 minutes after infusion]

Secondary outcome measures (4)

• change of extracellular electrolyte concentrations [Time frame: 300 minutes after infusion]
• change of intracellular electrolyte concentrations [Time frame: 300 minutes after infusion]
• change of osmolality [Time frame: 300 minutes after infusion]
• change of cell volume [Time frame: 300 minutes after infusion]

Eligibility criteria

Inclusion criteria

• Adult patients ≥18 years
• Requirement of renal replacement therapy due to surgical (i.e., nephrectomy) or non-surgical (chronic kidney disease) reason
• Stable hemodialysis treatment for at least 3 months
• Urine output <100ml in 24 hours
• Glucose-corrected plasma sodium between 135 mmol/l and 145 mmol/l
• Plasma potassium between 3.5 mmol/l and 5 mmol/l
• Written informed consent

Exclusion criteria

• Peritoneal dialysis patients
• Signs of volume expansion or contraction
• Congestive heart failure (NYHA ≥2)
• acute illness (infection, congestive heart failure, liver cirrhosis, etc.) requiring hospital admission
• Uncontrolled arterial hypertension
• Hemoglobin ≤8g/dL
• Alcohol abuse
• Malnutrition
• Persons, who are in a dependency/employment relationship with the investigators
• Accommodation in an institution by judicial or administrative order

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Non-randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Basic science

Study locations

Germany · 1 center

• Department II of Internal Medicine,University of Cologne — Cologne

Identifiers

NCT: NCT06408077 · V1.2_2023-06-06

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗