A Case of Postpartum Hypopituitarism (Sheehan's syndrome) Associated with Severe Hyponatremia and Congestive Heart Failure

A case of a 69-year-old woman with postpartum hopopituitarism (Sheehan's syndrome) associated with congestive heart failure and severe hyponatremia is reported. She developed congestive heart failure after cholecystectomy, and marked improvement was noted by treatment with oxygen, digoxin, furosemide, and dopamine. Two weeks after surgery, she became confused, and hyponatremia, 106 mEq/l, was detected. She was referred to us. Past history revealed postpartum hemorrhage at the age of 34, followed by a failure to lactate, menoschesis, and loss of pubic hair and axillary hair. Hypertonic saline (1.5%) infusion and water restriction increased her serum sodium concentration into the low normal range. Despite hyponatremia, serum vasopressin was not suppressed. Basal levels of pituitary hormones were low, and they did not respond to provocation tests. Marked impairment of water excretion was noted, and plasma vasopressin was not suppressed during a water-loading test. These results suggest that inappropriately increased vasopressin played an important role in impaired water excretion, and this defect could have been responsible for the development of hyponatremia and congestive heart failure in this patient.