The most common ingredients in these ice melts are sodium chloride, potassium chloride, magnesium chloride, calcium carbonate, and calcium magnesium acetate. A few ice melts contain urea. Sodium chloride Sodium ion toxicosis is possible after large ingestions of ice melts, salt, or rock salt. Ingesting large amounts of sodium leads to hypernatremia, osmotic diuresis, and increased urine osmolality. Increases in sodium retention let sodium passively diffuse into the cerebrospinal fluid.
Active transport is required to remove sodium from the cerebrospinal fluid.
Because energy is required for active transport, extracellular sodium concentrations usually decrease faster than sodium concentrations in the cerebrospinal fluid. Sodium trapped in the central nervous system attracts water because of the osmotic gradient, resulting in cerebral edema. The gastroenteritis and diuresis that occur may combine to cause dehydration, further worsening the patient's condition. The clinical signs of hypernatremia are primarily neurologic and related to osmotic movement of water out of brain cells. The severity of the clinical signs is related more to the rapidity of the onset of hypernatremia than the magnitude.