An elderly man with diabetes presents with dehydration and confusion after being found outdoors in cold weather. Which condition is most likely to explain his acute mental status changes?

An elderly man with diabetes presents with dehydration and confusion after being found outdoors in cold weather. Which condition is most likely to explain his acute mental status changes?

• A. Hyperglycemic hyperosmolar state
• B. Lactic acidosis
• C. Stroke
• D. Urinary tract infection

Answer: (A)

The situation points to hyperosmolar hyperglycemic state. In elderly diabetics, especially type 2, dehydration from osmotic diuresis can be precipitated by illness or stress—cold exposure with poor intake fits this pattern. The resulting severe hyperglycemia raises serum osmolality, which pulls water out of brain cells and leads to confusion and other mental status changes. Unlike diabetic ketoacidosis, there is little or no significant ketosis or acidosis, even though glucose levels are very high and volume depletion is marked. This combination—very high glucose with high osmolality and notable dehydration—best explains the acute mental status change. Lactic acidosis would typically present with metabolic acidosis and signs of hypoperfusion; a stroke would usually produce focal neurological deficits; a urinary tract infection can cause delirium but not the dramatic hyperglycemia and osmolar disturbance seen here.

The situation points to hyperosmolar hyperglycemic state. In elderly diabetics, especially type 2, dehydration from osmotic diuresis can be precipitated by illness or stress—cold exposure with poor intake fits this pattern. The resulting severe hyperglycemia raises serum osmolality, which pulls water out of brain cells and leads to confusion and other mental status changes. Unlike diabetic ketoacidosis, there is little or no significant ketosis or acidosis, even though glucose levels are very high and volume depletion is marked. This combination—very high glucose with high osmolality and notable dehydration—best explains the acute mental status change.

Lactic acidosis would typically present with metabolic acidosis and signs of hypoperfusion; a stroke would usually produce focal neurological deficits; a urinary tract infection can cause delirium but not the dramatic hyperglycemia and osmolar disturbance seen here.