Objectives
To assess symptoms and characteristics of hyponatremia, the most common electrolyte disturbance in hospitalized individuals and a condition that is associated with substantial morbidity and mortality.
Design
Prospective observational multicenter study.
Setting
Two Swiss academic centers.
Participants
Individuals with profound hypoosmolar hyponatremia (sodium <125 mmol/L) (N = 298).
Measurements
All symptoms and complete medical history including current medications, therapy management, and in‐hospital outcomes were recorded.
Results
The median age of all participants was 71 (interquartile range (IQR) 60–80), 195 (65%) were female, and mean serum sodium value on admission was 120 mmol/L (IQR 116–123 mmol/L). Frequent clinical symptoms were nausea (n = 130, 44%), acute vomiting (n = 91, 30%), generalized weakness (n = 205, 69%), fatigue (n = 175, 59%), gait disturbance (n = 92, 31%), recurrent falls (n = 47, 16%), and acute falls (n = 60, 20%). Fractures were reported in 11 participants (4%). More‐severe symptoms such as acute epileptic seizures and focal neurological deficits were identified in 16 (5%) and 17 (5%) participants, respectively. The most common comorbidities were hypertension (n = 199, 67%), congestive heart failure (n = 44, 15%), chronic renal failure (n = 64, 21%), pulmonary disease (82, 28%), and central nervous system disease (n = 114, 38%). During hospitalization, 12 (4%) participants died, and 103 (35%) needed treatment in the intensive care unit.
Conclusion
A wide spectrum of symptoms accompanies profound hyponatremia. Most participants had moderate symptoms mirroring chronic hyponatremia with brain cell adaptation. Participants with profound hyponatremia had several comorbidities.