What is Hyponatremia?

Hyponatremia is the most common form of electrolyte imbalance.  It is a condition of abnormally low sodium concentration, usually defined as serum sodium <135 mEq/L.

Although it has been recognized for decades, hyponatremia is still not fully understood.  This may be partially due to the fact that it is associated with a wide range of underlying disease states.  Hyponatremia is a potentially serious condition, yet assessment can be challenging and strategies for treatment have traditionally been suboptimal.  A better understanding of hyponatremia and knowledge of recent advances in treatment, are therefore an important part of improving patient care.

Types:

There are 3 types of hyponatremia that are differentiated by volume status: hypervolemic, euvolemic, and hypovolemic.

Hyponatremia results from a relative excess of water in relation to sodium.  In dilutional hyponatremia, total body water is increased.

Symptoms:

Hyponatremia is more likely to be symptomatic when the decrease in serum sodium concentration is large and occurs rapidly.  It is important to recognize, however, that the clinical presentation of hyponatremia can be quite variable.

Acute symptomatic—In acute symptomatic hyponatremia, serum sodium concentration falls rapidly (in less than 48 hours).

Chronic (symptomatic or asymptomatic)—Chronic hyponatremia is defined as hyponatremia lasting more than 48 hours or with an unknown duration.  In patients with chronic hyponatremia, treatment must be addressed cautiously because of adaptation by the brain to this prolonged state.  Chronic asymptomatic hyponatremia generally calls for a more conservative approach than chronic symptomatic hyponatremia.

Interestingly, although mild, chronic hyponatremia is often thought to be asymptomatic, a recent study found that it actually can be accompanied by impairments in both gait and attention.  In a case-control study, Renneboog et al found that 21.3% of patients with chronic, asymptomatic hyponatremia were admitted to the ER with falls, compared with 5.3% of control patients—the authors hypothesized a link between falls and the impairments in gait and attention.

In patients with severe hyponatremia (serum sodium <125 mEq/L), central nervous system symptoms predominate and can progress to seizures, coma, or death.  Other neurological symptoms include:

P      Headache

P      Muscle cramps

P      Reversible ataxia

P      Psychosis

P      Lethargy

P      Restlessness

P      Disorientation

P      Apathy

P      Anorexia

P      Agitation

Neurological symptoms are generally less common in patients with chronic or mild hyponatremia (serum sodium >125 mEq/L).

Nonneurological symptoms of hyponatremia include:

P      Fatigue

P      Thirst

P      Weakness

P      Cramping

P      Nausea

P      Vomiting

P      Bloating

P      Swelling

P      Tightness of hands and feet

Do you know someone who has Euvolimic Hyponatremia?

UCRT is participating in a clinical research trial for a study drug looking at individuals with mild to moderate Euvolimic Hyponatremia.  Qualified participants will receive study-related evaluations, lab work, electrocardiograms, and doctor’s consultation at no charge while taking part in the study.

Eligible participants must:

• Be male or female, at least 18 years of age
• Be diagnosed with Euvolimic Hyponatremia (Na+ < 135mEq/L)
• Be willing to be observed in a monitored setting for approximately the first 8 hours following treatment initiation (first dose)

     If someone you know has Euvolimic Hyponatremia and you think they meet the above criteria for eligibility to enrol in this study, please contact us at Universal Clinical Research & Technology (UCRT) at 407.574-3801 or 407.574-7361.

     For more information on this and other clinical studies, please call Garry or Marla at 407-574-3801.