[A case report of hyperosmolar hyperglycemic non-ketotic coma after aortic valve replacement].

A 56-year-old man without a past history of diabetes mellitus underwent aortic valve replacement. On the 8th postoperative day, the patient became confused with a peak blood glucose level of 600 mg/dl and peak serum osmolarity level of 411 mOsm/l, without ketotic urine. The diagnosis of hyperosmolar hyperglycemic non-ketotic coma (HHNKC) was made, and the patient was immediately treated with massive infusion of 0.45% saline water and continuous insulin administration, and the patient could completely recover. It is important to prevent and keep in mind the complication of HHNKC for the postoperative care after open heart surgery.