Fatal hypernatremia from exogenous salt intake: report of a case and review of the literature

Abstract

Hypernatremia is a common electrolyte disturbance, most often caused by volume depletion. Hypernatremia due to sodium excess occurs less frequently, and fatal hypernatremia solely from ingestion of table salt is rare. We describe a 41-year-old man who had seizures and hypernatremia after ingestion of a supersaturated salt water solution intended for gargling. He had consumed approximately a third cup of table salt (approximately 70 to 90 g of salt or 1,200 to 1,500 meq of sodium). His initial serum sodium concentration was 209 meq/liter. Hypotonic fluid therapy was given to provide free water and to correct the hypernatremia gradually. Our patient, however, failed to recover from the initial insult and died 3 days later. Review of the literature revealed 10 adult and 20 pediatric cases of hypernatremia attributable to exogenous intake of salt. The type of therapy (fluid or peritoneal dialysis), the type of fluid used, and the rate of correction of hypernatremia did not influence survival. The age of the patient and the initial serum sodium concentration were the most important prognostic indicators. Both very young patients and those with lesser degrees of hypernatremia had a better rate of survival than did other patients. In addition, our review illustrates the surprisingly small amount of salt that can cause severe hypernatremia and the danger of using salt or saline as an emetic.