Hyperosmolar nonketotic syndrome with hypernatremia: how can we monitor treatment?

We report the case of a 62 year-old symptomatic patient with severe hyperglycemic hyperosmolality associated with hypernatremia. During treatment, the progressive decrease in serum tonicity, which resulted in the amelioration of the neurological symptoms, followed the decrease in serum glucose and mainly the corrected serum sodium levels rather than the decrease in the uncorrected serum sodium levels. The case illustrates the usefulness of glucose - corrected serum sodium levels to monitor treatment in such conditions in order to avoid neurological consequences caused by the decrease in serum osmolality.