Severe hyponatraemia: complications and treatment

Area of Science:

• Nephrology
• Neurology
• Internal Medicine

Background:

• Severely hyponatraemic patients (sodium <= 120 mmol/l) admitted to hospitals often experience neurological complications.
• Chronic hyponatraemia (> 3 days duration) is prevalent in these patients, with 79% affected in this study.
• Neurological manifestations during hyponatraemia include altered consciousness, seizures, and long tract signs.

Purpose of the Study:

• To determine the incidence of complications in severely hyponatraemic patients.
• To investigate the relationship between the rate of sodium correction and patient outcomes.
• To establish safe correction rate guidelines for severe hyponatraemia.

Main Methods:

• Retrospective and prospective evaluation of 184 patients (84 in New York, 100 in Oxford) with serum sodium <= 120 mmol/l.
• Ascertainment of hyponatraemia cause, management strategies, and patient outcomes.
• Analysis of neurological complications during hyponatraemia and after correction, correlating them with correction rates.

Main Results:

• High incidence of neurological symptoms during hyponatraemia (76% with altered consciousness, 11% in coma).
• Observed complications post-correction include central pontine myelinolysis (0.5%) and seizures (1.0%).
• Faster correction rates (mean 12.1 mmol/l/24h) were significantly associated with neurological sequelae compared to slower rates (8.2 mmol/l/24h).

Conclusions:

• Neurological sequelae in severely hyponatraemic patients are linked to rapid correction rates.
• Correction of chronic severe hyponatraemia should ideally be maintained below 10 mmol/l within 24 hours.
• Careful monitoring and controlled correction are crucial to prevent adverse outcomes in hyponatraemia management.