[Acute Aortic Dissection Surgery Complicated by Nephrogenic Diabetes Insipidus]

Hypernatremia due to polyuria following cardiac surgery is rare. We report a case that required to identify the cause of massive polyuria. A 50-year-old male underwent aortic arch replacement for acute aortic dissection. Early postoperatively, he developed marked polyuria [over 3,000 ml within 6 hours after intensive care unit (ICU) admission, over 15,000 ml within 24 hours] and hypernatremia (peak value 187 mEq/l). We first assumed vasopressin deficiency due to cardiopulmonary bypass, and desmopressin nasal spray was somewhat effective. Continuous vasopressin infusion combined with massive 5 % glucose infusion started to reduce serum sodium value to 160 mEq/l. Neither a vasopressin challenge test on post operative day 16 nor a water restriction test on post operative day 48 demonstrated an increase in urine osmolality, leading to a diagnosis of nephrogenic diabetes insipidus. This case highlighted the complexity of fluid management when nephrogenic diabetes insipidus complicates postoperative course after surgery using cardiopulmonary bypass.