Normo-osmolar, nonketotic, hyponatremic diabetic syndrome associated with impaired renal function

A case is reported of a nonketotic woman with diabetes who presented with a blood glucose of 72.8 mmol/L (1310 mg/dl), plasma sodium of 92 mmol/L, normal osmolality, impaired renal function, and alert clinical state. Before the implication of the unusual nature of the metabolic disturbance was fully considered, the initial treatment was with a rapid infusion of saline. On consideration, however, it was postulated that as her hyperglycemia had developed, the expected osmotic diuresis was prevented by the impairment of her renal function. This had allowed compensatory hyponatremia to develop to maintain normal osmolality and protect the patient from coma. The high-dose saline infusion was stopped, and she was successfully treated with insulin and potassium but only minimal saline. The use of large quantities of saline in normo-osmolar, nonketotic, hyponatremic diabetic syndrome associated with impaired renal function and alert mental state is unnecessary and potentially dangerous.